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BCA bolt action upper for $350? (Page 5 of 21)
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Originally Posted By PreacherOfGadget: You don't need to be an engineer to have a good idea, and this is one. Maybe it'll work fine as is. Maybe it'll only work if it's a bit shorter. Clearly you're good at working through this fairly logically. Lantac did something similar, so it's a matter of how to make it work. The absolute worst that happens is we'll all learn something if it fails. I'm in this for the process as much as the outcome.  |
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Originally Posted By NorthPolar: I wonder if you could get small enough roller bearings to mount to that, make the bolt movement smoother Took me a little while to envision what you are getting at. Am I on target? |
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Originally Posted By PreacherOfGadget: You don't need to be an engineer to have a good idea, and this is one. Maybe it'll work fine as is. Maybe it'll only work if it's a bit shorter. Clearly you're good at working through this fairly logically. Lantac did something similar, so it's a matter of how to make it work. The absolute worst that happens is we'll all learn something if it fails. I'm in this for the process as much as the outcome. |
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Originally Posted By VTD: Roller bearings on the back of the bracket that contact the outside of the receiver and take up the slack? Reducing the amount of side pressure? Took me a little while to envision what you are getting at. Am I on target? Yup, would need small ones so they can roll when the bolt moves but still |
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Bolt Catching During Cycling the cause Below is a TROMIX bolt. It differs in lug geometry in that one side has been The red rectangles indicate the radiused edge on a standard AR bolt that ensure the lugs disengage smoothly. The green rectangles indicate the edge that should be radiused to disengage when turning the opposite direction, as this bolt upper does.   the fix I haven't done it yet, but dollars to donuts the definitive solution is to lightly radius the green-rectangle edges all the way around the bolt using a stone, small metal file, etc. Then polish. Hmmm.... Would starting with a left handed bolt optimized with radii as above be a solution? Do left handed carriers rotate their bolts the opposite direction? ---------- Correction, while hard to see in my crumby pictures, the edge is actually chamfered, not radiused. Either should work as a fix. |
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Originally Posted By PreacherOfGadget: Bolt Catching During Cycling the cause Below is a TROMIX bolt. It differs in lug geometry in that one side has been The red rectangles indicate the radiused edge on a standard AR bolt that ensure the lugs disengage smoothly. The green rectangles indicate the edge that should be radiused to disengage when turning the opposite direction, as this bolt upper does. https://i.imgur.com/8h6b0zo.jpeg https://i.imgur.com/sE2E194.jpeg the fix I haven't done it yet, but dollars to donuts the definitive solution is to lightly radius the green-rectangle edges all the way around the bolt using a stone, small metal file, etc. Then polish. Hmmm.... Would starting with a left handed bolt optimized with radii as above be a solution? Do left handed carriers rotate their bolts the opposite direction? ---------- Correction, while hard to see in my crumby pictures, the edge is actually chamfered, not radiused. Either should work as a fix. I guess it does. Attached File |
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Attached File Attached File (Ignore the selector position....I popped it on an frt equipped sbr lower because it was the closest  )It took three tries but this one was the charm. As stated before, it moves the bolt handle 2" rearward. Being plastic I don't want to slam it back and forth super hard but running the bolt fairly quickly there is no binding going on at all. I think you could get away wth 2.5" without ill effect. The position is very nice and dramatically speeds things up IMO. If this was metal it could be a bit thinner. I broke the two first prints and ended up learning where the weakest spots were. Beefed them up on the third print. |
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Sweet work on the handle extension! I'm uncertain what length I'd personally prefer or what would work best. Maybe get a custom place like Paladin machine shop to make a steel prototype at some point? If that works... I'd be in for at least one. Also, I see no problem with a fully automatic bolt action rifle. Embrace the dichotomy and confusion! re: bolt retraction issues, cont'd I've started chamfering the edges on my BCA bolt to see if I could improve cycling reliability, and with my last grinding it drastically decreased, but didn't cease. There's more work to do, and my job was really rough, but I'm approaching proof of concept on nailing down a fix to the underlying issue. This is the first time I've modified a bolt in any way other than polishing the face |
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Originally Posted By PreacherOfGadget: Sweet work on the handle extension! I'm uncertain what length I'd personally prefer or what would work best. Maybe get a custom place like Paladin machine shop to make a steel prototype at some point? If that works... I'd be in for at least one. Also, I see no problem with a fully automatic bolt action rifle. Embrace the dichotomy and confusion! re: bolt retraction issues, cont'd I've started chamfering the edges on my BCA bolt to see if I could improve cycling reliability, and with my last grinding it drastically decreased, but didn't cease. There's more work to do, and my job was really rough, but I'm approaching proof of concept on nailing down a fix to the underlying issue. This is the first time I've modified a bolt in any way other than polishing the face Glad to see the progress on the bolt! |
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Originally Posted By VTD: I sent a couple of emails to different local machine shops to inquire about metal prototypes. We will see what happens. I have a feeling that another half inch would be the sweet spot. Glad to see the progress on the bolt! |
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Originally Posted By VTD: https://www.ar15.com/media/mediaFiles/26478/IMG_0347_JPEG-3486115.JPG https://www.ar15.com/media/mediaFiles/26478/IMG_0349_JPEG-3486116.JPG (Ignore the selector position....I popped it on an frt equipped sbr lower because it was the closest )It took three tries but this one was the charm. As stated before, it moves the bolt handle 2" rearward. Being plastic I don't want to slam it back and forth super hard but running the bolt fairly quickly there is no binding going on at all. I think you could get away wth 2.5" without ill effect. The position is very nice and dramatically speeds things up IMO. If this was metal it could be a bit thinner. I broke the two first prints and ended up learning where the weakest spots were. Beefed them up on the third print. I love it. |
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Originally Posted By ELittlefield: I'll just add that both of my uppers are still cycling very smoothly if I apply pressure to the left as I run the bolt. |
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Originally Posted By ELittlefield: It's disappointing that the gas cut off sleeves will not be included. It would have been a very, very easy inclusion that makes it easier for new buyers. I have spare gas blocks, but not everyone does. https://www.ebay.com/itm/133069054574?mkcid=16&;mkevt=1&mkrid=711-127632-2357-0&ssspo=1k0yVNwvROm&sssrc=4429486&ssuid=hkc3qm4orzw&var=&widget_ver=artemis&media=COPY |
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So, as far as the bolt catching the extension during cycling... I have greatly reduced this by beveling rear edges of the bolt face, but I've reached a point where I've removed more than I like. This is what happens when parts designed to only have linear forward-rearward forces applied are being manipulated by a force applied some distance from the center of rotation. This setup can have forces applied to the BCG that are panning and tilting, along with side-to-side and up-down forces. I feel it would require someone with proper machining skills to safely modify the bolt to reliably account for all of this. I'm not giving up, but I'm a bit discouraged. And stopping for the day. |
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Originally Posted By PreacherOfGadget: So, as far as the bolt catching the extension during cycling... I have greatly reduced this by beveling rear edges of the bolt face, but I've reached a point where I've removed more than I like. This is what happens when parts designed to only have linear forward-rearward forces applied are being manipulated by a force applied some distance from the center of rotation. This setup can have forces applied to the BCG that are panning and tilting, along with side-to-side and up-down forces. I feel it would require someone with proper machining skills to safely modify the bolt to reliably account for all of this. I'm not giving up, but I'm a bit discouraged. And stopping for the day. Looking at this video, as I'm sure we all have, this is probably why they move with authority running the action. With that said, I totally get they are combining two actions into one.  Failed To Load Title This is probably why in every video I've seen there is never a light BBL used with this gun. Which is telling me, yes I hear voices  sometimes, that this is intended for bench shooting. |
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Originally Posted By azoutdoorsman: Sucks but here's a solution. Put the set screw right over the gas port. https://www.ebay.com/itm/133069054574?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=1k0yVNwvROm&sssrc=4429486&ssuid=hkc3qm4orzw&var=&widget_ver=artemis&media=COPY Originally Posted By azoutdoorsman: Originally Posted By ELittlefield: It's disappointing that the gas cut off sleeves will not be included. It would have been a very, very easy inclusion that makes it easier for new buyers. I have spare gas blocks, but not everyone does. https://www.ebay.com/itm/133069054574?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=1k0yVNwvROm&sssrc=4429486&ssuid=hkc3qm4orzw&var=&widget_ver=artemis&media=COPY Yep, I tried something very similar, and went back to a spare gas block for the looks. |
| I second Paladin for a metal sample. He has done dozens of one-offs for me on my crazy projects and I feel this would be no hill for him to climb. Send him the sample and I am sure he can make it in either aluminum or steel or both, IF he wants the work. Contact him at tp555(at)vfemail.net. And the price is not going to break your wallet either and you'll have it in a week or two, not months. Email him with a sketch with measurements and a few pictures of your prototype and he'll get back with you in a few hours or a day at most. And he's honest, he is not going to take your project and patent it to screw you out of any royalties should you want to patent it later. |
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Originally Posted By TNRonin: At this point maybe look at the BBL extension? Looking at this video, as I'm sure we all have, this is probably why they move with authority running the action. With that said, I totally get they are combining two actions into one. [...] This is probably why in every video I've seen there is never a light BBL used with this gun. Which is telling me, yes I hear voices sometimes, that this is intended for bench shooting. Actually, I usually don't watch videos -- more of a reader than a watcher on most topics. Thanks for pointing me toward it. I think you're on the right track as far as the extension. The bolt needs pretty much every back edge of the lugs chamfered to account for all the "twisty" directional forces that come into play. As far as my barrel (Tromix) on this upper, I'm not touching the extension. And I have the barrel bedded with green locktite. Experimentation on extension will have to wait until I have another upper. One thing I will say, is if the radius of the rear screw head on the bolt handle is increased enough (beyond the diameter of the handle's base), it forces the handle slightly upward as it starts to retract, and this reduces this issue. It doesn't eliminate it, but it does help by reducing the effect of *some* of those sets of forces. |
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Originally Posted By ELittlefield: Range Report: This is a bit of a funky gun. It does not run like a typical bolt action at all. After fiddling with it indoors without ammo, and figuring out the motion to use, I was well equipped to run live ammo. Running the bolt briskly while maintaining gentle pressure toward the left resulted in perfectly smooth operation. There were no failures to feed, failures to extract, or bolt hang ups at all. However, you can forget about running the bolt like you might a purpose built bolt action like a mauser. It's simply not ergonomic, the bolt handle is way too far forward. My ear could not discern any difference between an inverted gas block and the McMaster Carr shaft collar. I was shooting suppressed, and it was easily hearing safe either way with subsonics. I stuck with the gas block because it looks a little better to me, but I would not hesitate to use the collar either. My alignment rod told me that the threads on the Bear Creek barrel were sufficiently concentric to use a silencer, and shooting it confirmed that, with no baffle strikes. Accuracy was okay. Comparable with several other guns I shot today, mostly non free floated 5.56 ARs with red dots. Here's 3 groups at 35 yards. I do not claim to be a good shooter. https://i.imgur.com/3qLCmoN.jpeg" target="_blank">https://i.imgur.com/3qLCmoN.jpeg The 450, I only shot 4 rounds to check basic function, because I don't have magazines yet. On this gun, I had to sharply run the bolt forward and down to get the extractor to snap over the rim. Extraction was again perfect when I ran the bolt as described. I would 100% recommend this upper platform for people who are willing to put up with some quirks as a novelty, or a pest control gun, or especially as a silencer host. I would not recommend it for hunting. It would be a shame to have the gun lock up if you get buck fever and run the bolt wrong. I'm eager to read other people's thoughts as they get some trigger time. Have you measured the ejection opening on the 450? Just wondering if it is more opened than the 223, 300 bo etc. to eject that fat case. You would think it would be. Thanks in advance, I still havent made up my mind which to order lol or to wait for the 308 version bolt and upper. I see they have the completed version out now for the 308..............also on the bolt handle, would it be possible to just take if off the bolt, heat it, and then bend it closer? Just a thought I had lol. |
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Originally Posted By Southernfried: Have you measured the ejection opening on the 450? Just wondering if it is more opened than the 223, 300 bo etc. to eject that fat case. You would think it would be. Thanks in advance, I still havent made up my mind which to order lol or to wait for the 308 version bolt and upper. I see they have the completed version out now for the 308..............also on the bolt handle, would it be possible to just take if off the bolt, heat it, and then bend it closer? Just a thought I had lol. I bought before the receiver sets were out. I am curious to any measured responses, as I believe there should be no difference in the port door opening, because expansion upward would expose the key and cam pin, the recess cut for those already provides an increase for part of the depth/length of the port door, and any expansion downward would cause the bolt to be misaligned with the receiver extension so the bolt wouldn't rotate far enough to unlock for extraction and would meet resistance closing. My upper was 5.56. I rebuilt it as a .375 SOCOM. .375 SOCOM case width is the same as .458 SOCOM, wider than .450 BM, and just a couple thousandths shy of the .50 Beowulf case width. I had issues cycling about 80% of (live) rounds initially due to ejection issues. It was caused by sharp edges along the port door on the inside of the receiver catching the brass instead of it sliding over those edges. There's posts with pictures in previous pages of how I did some light filing and sanding with 1k-3k grit sandpaper to smooth these edges. I may have gone a little heavy. After cleaning those edges up, 0 ejection issues. I don't know if those edges are so rough in all their receivers, or if mine was a fluke/QC-fail/non-issue because it wasn't to be sold as a large bore upper and could eject 5.56 just fine. Even if there isn't a separate large-bore receiver, unless you've found a round with a case larger than the Beowulf, you should be well within the realm of a functional solution either out of the box or with little, if any modification. |
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Originally Posted By Big-Bore: I second Paladin for a metal sample. He has done dozens of one-offs for me on my crazy projects and I feel this would be no hill for him to climb. Send him the sample and I am sure he can make it in either aluminum or steel or both, IF he wants the work. Contact him at tp555(at)vfemail.net. And the price is not going to break your wallet either and you'll have it in a week or two, not months. Email him with a sketch with measurements and a few pictures of your prototype and he'll get back with you in a few hours or a day at most. And he's honest, he is not going to take your project and patent it to screw you out of any royalties should you want to patent it later. |
| FYI, I mailed out a blank, reamer… to Paladin last Monday via FedEx for him to make a cat barrel and case gauge. He got it last Wednesday. I got an email about 3 hours ago that it’s on its way back to me. 4 day turn around. And that is typical for him. And I can speak from years of experience using him that the barrel will be a work of art when it gets here. |
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Originally Posted By Big-Bore: FYI, I mailed out a blank, reamer to Paladin last Monday via FedEx for him to make a cat barrel and case gauge. He got it last Wednesday. I got an email about 3 hours ago that it's on its way back to me. 4 day turn around. And that is typical for him. And I can speak from years of experience using him that the barrel will be a work of art when it gets here. I just fired off an email with pictures and a description a few minutes ago. |
| Yeah this is going to work out well. Went to the range when nobody was there. 10 round group at 62 yd roughly inch and a quarter. Not bad considering I had a stroke and I'm shooting from the affected side. If you'll do your job it'll do its job. And that was actually with the 77 grain OTM. |
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Originally Posted By thederrick106: I also found the bolt operation to be a bit fiddly at first vs a traditional bolt action rifle. The more I worked it the better it seemed to operate. When I put an empty mag in it greatly improved the opening and rearward movement of the bolt. I just got my first complete upper mated to a lower yesterday and haven't had a chance to function test it with live ammo yet. My first impressions are that the bolt will work smoother with a loaded mag and ammo. I also feel like these will have a bit of a "break in period" as well. I was doing this with a 556 upper. I finally got a chance to run the bolt on some live ammo. Bolt operates very well on live ammo with no issues. Once some of this snow melts, I will get it out on my range. Already have an optic mounted on it and ready to get it sighted in. |
Originally Posted By ar-jedi:
SO MUCH WIN IN ONE POST IT COULD CRASH ARFCOM !!!
SO MUCH WIN IN ONE POST IT COULD CRASH ARFCOM !!!
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Originally Posted By thederrick106: I finally got a chance to run the bolt on some live ammo. Bolt operates very well on live ammo with no issues. Once some of this snow melts, I will get it out on my range. Already have an optic mounted on it and ready to get it sighted in. Originally Posted By thederrick106: Originally Posted By thederrick106: I also found the bolt operation to be a bit fiddly at first vs a traditional bolt action rifle. The more I worked it the better it seemed to operate. When I put an empty mag in it greatly improved the opening and rearward movement of the bolt. I just got my first complete upper mated to a lower yesterday and haven't had a chance to function test it with live ammo yet. My first impressions are that the bolt will work smoother with a loaded mag and ammo. I also feel like these will have a bit of a "break in period" as well. I was doing this with a 556 upper. I finally got a chance to run the bolt on some live ammo. Bolt operates very well on live ammo with no issues. Once some of this snow melts, I will get it out on my range. Already have an optic mounted on it and ready to get it sighted in. What's your build again? |
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Originally Posted By ELittlefield: What's your build again? Originally Posted By ELittlefield: Originally Posted By thederrick106: Originally Posted By thederrick106: I also found the bolt operation to be a bit fiddly at first vs a traditional bolt action rifle. The more I worked it the better it seemed to operate. When I put an empty mag in it greatly improved the opening and rearward movement of the bolt. I just got my first complete upper mated to a lower yesterday and haven't had a chance to function test it with live ammo yet. My first impressions are that the bolt will work smoother with a loaded mag and ammo. I also feel like these will have a bit of a "break in period" as well. I was doing this with a 556 upper. I finally got a chance to run the bolt on some live ammo. Bolt operates very well on live ammo with no issues. Once some of this snow melts, I will get it out on my range. Already have an optic mounted on it and ready to get it sighted in. What's your build again? Complete 556 upper w/ 20" barrel. |
Originally Posted By ar-jedi:
SO MUCH WIN IN ONE POST IT COULD CRASH ARFCOM !!!
SO MUCH WIN IN ONE POST IT COULD CRASH ARFCOM !!!
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Originally Posted By thederrick106: Complete 556 upper w/ 20" barrel. Originally Posted By thederrick106: Originally Posted By ELittlefield: Originally Posted By thederrick106: Originally Posted By thederrick106: I also found the bolt operation to be a bit fiddly at first vs a traditional bolt action rifle. The more I worked it the better it seemed to operate. When I put an empty mag in it greatly improved the opening and rearward movement of the bolt. I just got my first complete upper mated to a lower yesterday and haven't had a chance to function test it with live ammo yet. My first impressions are that the bolt will work smoother with a loaded mag and ammo. I also feel like these will have a bit of a "break in period" as well. I was doing this with a 556 upper. I finally got a chance to run the bolt on some live ammo. Bolt operates very well on live ammo with no issues. Once some of this snow melts, I will get it out on my range. Already have an optic mounted on it and ready to get it sighted in. What's your build again? Complete 556 upper w/ 20" barrel. Will you have a can on it? |
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Originally Posted By ELittlefield: Will you have a can on it? Originally Posted By ELittlefield: Originally Posted By thederrick106: Originally Posted By ELittlefield: Originally Posted By thederrick106: Originally Posted By thederrick106: I also found the bolt operation to be a bit fiddly at first vs a traditional bolt action rifle. The more I worked it the better it seemed to operate. When I put an empty mag in it greatly improved the opening and rearward movement of the bolt. I just got my first complete upper mated to a lower yesterday and haven't had a chance to function test it with live ammo yet. My first impressions are that the bolt will work smoother with a loaded mag and ammo. I also feel like these will have a bit of a "break in period" as well. I was doing this with a 556 upper. I finally got a chance to run the bolt on some live ammo. Bolt operates very well on live ammo with no issues. Once some of this snow melts, I will get it out on my range. Already have an optic mounted on it and ready to get it sighted in. What's your build again? Complete 556 upper w/ 20" barrel. Will you have a can on it? Thats a negative. They are not legal in NY. |
Originally Posted By ar-jedi:
SO MUCH WIN IN ONE POST IT COULD CRASH ARFCOM !!!
SO MUCH WIN IN ONE POST IT COULD CRASH ARFCOM !!!
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Tips for Tuning the BCA Bolt Action So, I said I'd have some pictures, and I do. But, before I go through various things I've done, I'm gonna skip to the end: I stumbled on what is for me a complete solution regarding bolt lugs catching on the barrel extension during extraction. 2 Solutions For your Bolt Lugs Catching the Barrel Extension Solution 1(proof of concept/overkill): Chamfer Rear Edges of Your Bolt Lugs I did a shitty job of this. Why? I don't have a steady hand and do have impatience. Using a backup BCA bolt, I grabbed a Dremel grinding wheel went nuts to find if here was a point where chamfered lugs would solve the problem. It does. I overdid the chamfers. Somewhere before your lugs are ground to this point, they'll allow the bolt to start sliding out of battery as the receiver extension lug edges will align with a chamfered edge. There is some resistance, but it's the resistance of angled metal sliding over corners, not flats of metal pushing straight at each other. One of the confusing things here is *which* faces need to be chamfered. In a semi-auto bolt, left or right handed, the chamfers are on the clockwise or counter-clockwise rear edges, respectively. In the bolt action, lower edges, regardless of clockwise-direction also need addressing. The outer edge of the lower lugs and possibly side lugs need this. The outer edges of the top lugs should not need this treatment. Alternatively for the outer edges, the barrel extension, between the lugs, could have the edges smoothed/chamfered, and thus loose less bearing surface area when closed as the outer edges of the bolt lugs wouldn't need to be chamfered.  Solution 2 (THE SIMPLE SOLUTION): Expand the diameter of the charging handle base at rear screw. Using a hard, thick very hard rubber washer of unknown type or origin that I found in some old plumbing supplies, I put it on the screw, put the screw in a drill press chuck, and spun it up. I sanded the edges until it was a little larger than the width of the charging handle base and screw head. When doing this, it was so hard, I thought it was a non-rubberized plastic because it was so firm. I am working to identify it.  This allows for quieter operation, as hard rubber is contacting metal instead of metal-on-metal. It can be tuned to create some resistance at the rear of cycling so the bolt can hold itself back with friction, if desired. Just adjusting the rear screw adjusts this tension effectively.  It also lifts the charging handle base high enough while retracting that I cannot, in this setup, recreate the bolt lugs catching malfunction. There isn't even perceptible contact between lugs as in solution 1 (Tromix Barrel and bolt, and the Tromix bolt has the lug chamfers of an enhanced right handed bolt (counter clockwise, viewed from rear). Shrink tubing (10mm, though I'd have used 8mm if I had some on hand) is around the front bolt, and it has proven quite good at dampening sound in that position, though it'll probably require replacement between 200 and 1k cycles of the action. Keeping one of the two screws with the metal lock washer ensures the charging handle stays secure. Charging Handle File/smooth lower edge of the pocket for the rear screw (green box). It can contact the edge of the receiver's pocket for the handle when locking the bolt shut if there's any rolling or burs. I went a bit heavier than I should have. File/smooth out the rear rounded face at the base of the charging handle (not boxed in picture). This slides over the same corner of the receiver's handle pocket, and also can damage the receiver.  Bolt Carrier Cut-off wings (yellow boxes) at the back of the receiver when fully retracted   CArrier & Carrier key Polish carrier to 3k grit after removing carrier key. Shape and polish the carrier key's sides (green box). Cam pin rounded and polished to 3k (red box). Before shape/polish  And after rounding the carrier key.  This smooths retraction as this corner makes contact with the receiver as the key aligns in the track on retraction. This occurs about 0.1" further retracted from the point when the bolt lugs catch the barrel extension. Charging Handle Screws -- the "Learning Attempts" So, these screws can affect a lot more than it seems at first glance. The screw heads and handle base make contact with all 3 sides of the receiver's pocket for locking the bolt shut, they slide along the receiver's charging handle cutout, and make impact with the front of port door when pushing it closed. Wrapping these screw heads in a softer material can quiet the sounds of the carrier slamming shut, locking shut, unlocking, and reaching the rear of retraction. Expanding the diameter of the rear bolt beyond the handle base causes the handle to rise higher when opening, reducing issues with the bolt lugs catching on the barrel extension -- this last item escaped my notice until the general issue of the bolt lugs catching was brought to my attention, as I wasn't having those issues. Unfortunately all my solutions are in the category of consumable items. I have a couple more approaches regarding the rear screw to attempt, and I'll go over them later, but this is what I've tried so far. Electrical Tape Wrap (Green box) Pros: Completely customizable in diameter. Cheap. Wrapped to max diameter, very quiet. Cons: Consumable fast. Replacement of rear screw head wrap needed every 25-30 action cycles. Front screw at about 50.  O-Rings in place of split ring washers (green box) and around the screw head. Pros: Easy fix. Not very expensive. Many configuration methods with multiple o-rings on screw shaft or around screw head. Quiet if o-rings are along screw shaft and screw tightened until bulging out, or over the screw heads. Last a very long time if on shaft and not very tight. Cons: The quieter it gets, the faster it wears. Front o-ring wears fast or provide negligible sound dampening. Can't be done on both screws without causing loose handle issues.  A view of the smoothed rear face of charging handle base (blue arrow).  Rubber Washers & Shrink Tubing The rubber washers bound up at full size, so they needed to be trimmed. Pros: Pretty darned quiet if tight. Cons: Bind up. Break faster when tightened to run quieter. Front one breaks very fast/binds up constantly. The shrink tubing showed drastic differences in performance between screws. Pros: Front screw covered in 2 layers of shrink tubing can last for 400+ cycles of action. Re-tightening shrink tubing can be done with heat several times before it wears out. It notably softens the blow of the bcg closing. Cons: Rear screw lasted about 10-15 cycles before starting to break up. Front one needs occasional tuning.  --------------- ETA: I've not yet figured out the material or specific rubberized plastic washer I used on the screw above. The thick rubber washers I've bought at the hardware store and tried so far do not match. However, a thick nylon washer seems to work well for this. (Thin nylon washers will fail. Tried that before any of the above attempts.) |
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i emailed BCA about my upper and bolt not coming with a gas port sleeve, they have already shipped one out to me. for the time being i cut down a spare FSB and used the end that does not have a gas port. i tried to make this thing decently light but not overboard with titanium and counting ounces. main use will be porch shooting and armadillo/coon eradication using handloaded subs and getting this thing as quiet as possible. 16" faxon 300blk gunner profile Dark Hour Defense 11.1" magnesium mlok rail 5oz rearden R2S plan b mount CMC single stage trigger hogster r35 suppressor not shown lol i want to cut this bolt down to maybe be able to use KNS buffer/pic adapter and folding stock, but idk how itll effect the function of this thing yet. whose gonna be the first to add these uppers to a FM ranch rifle or Fightlite SCR lower to make the ultimate "i shoulda just bought classical bolt action" ?? 
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Originally Posted By Slyce: i emailed BCA about my upper and bolt not coming with a gas port sleeve, they have already shipped one out to me. for the time being i cut down a spare FSB and used the end that does not have a gas port. i tried to make this thing decently light but not overboard with titanium and counting ounces. main use will be porch shooting and armadillo/coon eradication using handloaded subs and getting this thing as quiet as possible. 16" faxon 300blk gunner profile Dark Hour Defense 11.1" magnesium mlok rail 5oz rearden R2S plan b mount CMC single stage trigger hogster r35 suppressor not shown lol i want to cut this bolt down to maybe be able to use KNS buffer/pic adapter and folding stock, but idk how itll effect the function of this thing yet. whose gonna be the first to add these uppers to a FM ranch rifle or Fightlite SCR lower to make the ultimate "i shoulda just bought classical bolt action" ?? https://i.postimg.cc/Dyq9zhBQ/LW-Thermal-BA-fixed.jpg That would be so ridiculous it would be epic. Being in NY I would love to have an SCR lower but I am not paying what they want for them. I will pick up one of their complete lowers if I ever find one for around $500 or less. I don't need or want one bad enough to spend 1K. |
Originally Posted By ar-jedi:
SO MUCH WIN IN ONE POST IT COULD CRASH ARFCOM !!!
SO MUCH WIN IN ONE POST IT COULD CRASH ARFCOM !!!
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Originally Posted By PreacherOfGadget: Solution 2 (THE SIMPLE SOLUTION): Expand the diameter of the charging handle base at rear screw. Using a hard, thick very hard rubber washer of unknown type or origin that I found in some old plumbing supplies, I put it on the screw, put the screw in a drill press chuck, and spun it up. I sanded the edges until it was a little larger than the width of the charging handle base and screw head. When doing this, it was so hard, I thought it was a non-rubberized plastic because it was so firm. I am working to identify it. I appreciate the write up 
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Originally Posted By Slyce: i emailed BCA about my upper and bolt not coming with a gas port sleeve, they have already shipped one out to me. for the time being i cut down a spare FSB and used the end that does not have a gas port. i tried to make this thing decently light but not overboard with titanium and counting ounces. main use will be porch shooting and armadillo/coon eradication using handloaded subs and getting this thing as quiet as possible. 16" faxon 300blk gunner profile Dark Hour Defense 11.1" magnesium mlok rail 5oz rearden R2S plan b mount CMC single stage trigger hogster r35 suppressor not shown lol i want to cut this bolt down to maybe be able to use KNS buffer/pic adapter and folding stock, but idk how itll effect the function of this thing yet. whose gonna be the first to add these uppers to a FM ranch rifle or Fightlite SCR lower to make the ultimate "i shoulda just bought classical bolt action" ?? https://i.postimg.cc/Dyq9zhBQ/LW-Thermal-BA-fixed.jpg |
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A little update on my bracket thingy. I took a couple of days and sort of learned how to use freecad so I could provide accurate dimensions and drawings to Paladin and see if he can help make a metal version. I moved the bolt handle back another half inch. Attached File Attached File Attached File |
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Originally Posted By VTD: A little update on my bracket thingy. I took a couple of days and sort of learned how to use freecad so I could provide accurate dimensions and drawings to Paladin and see if he can help make a metal version. I moved the bolt handle back another half inch. https://www.ar15.com/media/mediaFiles/26478/freecad_jpg-3488667.JPG https://www.ar15.com/media/mediaFiles/26478/IMG_0353_JPEG-3488669.JPGhttps://www.ar15.com/media/mediaFiles/26478/IMG_0354_JPEG-3488671.JPG Very nice! If you do get end up satisfied with a final version, I would be interested in buying one to try out, maybe three. 
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Originally Posted By ar-jedi:
SO MUCH WIN IN ONE POST IT COULD CRASH ARFCOM !!!
SO MUCH WIN IN ONE POST IT COULD CRASH ARFCOM !!!
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Originally Posted By VTD: A little update on my bracket thingy. I took a couple of days and sort of learned how to use freecad so I could provide accurate dimensions and drawings to Paladin and see if he can help make a metal version. I moved the bolt handle back another half inch. https://www.ar15.com/media/mediaFiles/26478/freecad_jpg-3488667.JPG https://www.ar15.com/media/mediaFiles/26478/IMG_0353_JPEG-3488669.JPGhttps://www.ar15.com/media/mediaFiles/26478/IMG_0354_JPEG-3488671.JPG Awesome work. Standing by for the outcome and possibly price point??? |
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Originally Posted By thederrick106: Very nice! If you do get end up satisfied with a final version, I would be interested in buying one to try out, maybe three. Originally Posted By Hijo202: Awesome work. Standing by for the outcome and possibly price point??? I'll keep you guys in the loop! I'm having fun and learning stuff anyway 
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Originally Posted By VTD: With my luck, Bear creek will probably come out with a gen2 with relocated bolt by the time I get anything made I'll keep you guys in the loop! I'm having fun and learning stuff anyway Originally Posted By VTD: Originally Posted By thederrick106: Very nice! If you do get end up satisfied with a final version, I would be interested in buying one to try out, maybe three. Originally Posted By Hijo202: Awesome work. Standing by for the outcome and possibly price point??? I'll keep you guys in the loop! I'm having fun and learning stuff anyway At the rate BCA is releasing these different budget options it wouldn't surprise me to see different generations over the short term. |
Originally Posted By ar-jedi:
SO MUCH WIN IN ONE POST IT COULD CRASH ARFCOM !!!
SO MUCH WIN IN ONE POST IT COULD CRASH ARFCOM !!!
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Originally Posted By VTD: With my luck, Bear creek will probably come out with a gen2 with relocated bolt by the time I get anything made I'll keep you guys in the loop! I'm having fun and learning stuff anyway Originally Posted By VTD: Originally Posted By thederrick106: Very nice! If you do get end up satisfied with a final version, I would be interested in buying one to try out, maybe three. Originally Posted By Hijo202: Awesome work. Standing by for the outcome and possibly price point??? I'll keep you guys in the loop! I'm having fun and learning stuff anyway No doubt about that. Sounds like my kinda luck as well. If you do get a price point from them, just let us know. It may be a minimum quantity required, but with the amount of these “Gen 1’s” out right now, it would benefit the other members. |
BCA bolt action upper for $350? (Page 5 of 21)
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