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BCA bolt action upper for $350? (Page 4 of 21)
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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. Whoever I was chatting with on their website was very clear that they were included. I don't get why they wouldn't be. |
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I am not a BCA apologist, nor am I a fanboy, I'm just a guy with a gun. But it seems like they're finding their way with this setup. Especially with all the twists and turns we're asking for. And they seem to be accommodating them. I will bet you dollars to donuts they'll start selling the collars. And they will be included in their sales of just the bolt and receiver. No guarantees, but common sense, and based on the way they've been doing business so far, they seem to be adapting and figuring it out. |
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Originally Posted By CORDrew: https://www.shawcustombarrels.com/shop/product/223-wylde-16-1-8-twist-ultralight-contour-*portless*/666 This is the only non-custom portless barrel I know of. I just turn a regular lo pro gas block backwards ie the port is to the muzzle end Tromix just sold me a .375 SOCOM barrels portless last week -- I just e-mailed before ordering to get instructions on how to order it as such. I'm guessing for any of their other barrels they may be able to do the same, but e-mail Tony Rumore to check. (Tromix sells .475 SOCOM, .458 SOCOM, and .450 Bushmaster barrels.) X-Caliber's custom AR-15 barrels have an option for "no port". Any truly "custom" barrel should be able to be made without a port. |
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My 16" 450 upper, and build kit and barrel for 300 arrived today. I built the 300 with a handguard I already had, and a random low profile gas block flipped front to back. It did NOT come with a sleeve/collar. The complete upper did come with a collar. Both uppers catch the bolt in the locking lugs when I attempt to unlock the bolt. The bolt has to be wiggled "just so" that the bolt body can be retracted. I don't know if that will smooth itself out, or if something will need to be done such as rounding the rear of the bolt lugs. I haven't had a chance to shoot the guns yet. I will do that tomorrow and report back, though I only own 20 rounds of 450 Bushmaster, and the magazines for that caliber haven't arrived yet. The 300 Blackout 10.5" barrel's muzzle threads are concentric enough to mount my Thunder Beast flash hider, and my alignment rod does not touch the mounted can. I wish the 458's muzzle threads were 5/8x24, instead of 5/8x32, because I have a fixed mount in that thread pitch for my Rugged Obsidian 45. This is of course not Bear Creek's fault, just a personal thing. I have an adapter on the way to mount it. |
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Attached File WTH is this review saying about the 10 throw? |
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Originally Posted By TNRonin: https://www.ar15.com/media/mediaFiles/13145/Screenshot_20250307_181220_Chrome_jpg-3484425.JPG WTH is this review saying about the 10 throw? He’s referring to 10 degrees of rotation to unlock the bolt. It is an extremely short bolt throw, but I don’t think it’s only 10 degrees. More like 22.5 degrees, or 1/16 of a complete circle. A follow up to me prior comment about the bolt lugs binding with the barrel extension: this only occurs when I try to run the bolt like a typical bolt action, in two moves of “up/back” and “forewarn/down.” If I release pressure on the bolt handle between lifting and pulling, it runs smoothly. I will try shooting tomorrow, and I may attempt the modification of rounding the bolt locking slot described in the video above. |
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Originally Posted By ELittlefield: He's referring to 10 degrees of rotation to unlock the bolt. It is an extremely short bolt throw, but I don't think it's only 10 degrees. More like 22.5 degrees, or 1/16 of a complete circle. A follow up to me prior comment about the bolt lugs binding with the barrel extension: this only occurs when I try to run the bolt like a typical bolt action, in two moves of "up/back" and "forewarn/down." If I release pressure on the bolt handle between lifting and pulling, it runs smoothly. I will try shooting tomorrow, and I may attempt the modification of rounding the bolt locking slot described in the video above. |
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Originally Posted By ELittlefield: Both uppers catch the bolt in the locking lugs when I attempt to unlock the bolt. The bolt has to be wiggled "just so" that the bolt body can be retracted. I don't know if that will smooth itself out, or if something will need to be done such as rounding the rear of the bolt lugs. Does it have a "standard" bolt with this unit and does it have a spring or something that pushes it forward to lock-up to shoot? If so, one of those Sharps "relia-bolt" or whatever they are called might work better. IIRC they have tapered bolt lugs on the front side of the bolt Just guessing... Nevermind - just reviewed the excellent post by Ninja99 on page 1 which shows the bolt and spring ETA - Ordered the 223/556 bolt action kit today along with a BCR 10.5 inch SS barrel. Have a spare handguard on hand and will run it suppressed for night time hunting....assuming it shoots good enough. Let the testing begin... |
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With additional dry fire and manipulation: The bolt must be pressed toward the left in addition to the normal bolt action turn and pull motions in order to cycle without binding on the barrel extension. Now that I've found the movement that works, it cycles properly both with a cocked trigger, and against a fired trigger to re cock it. I found this to be true on both uppers. |
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Originally Posted By ELittlefield: With additional dry fire and manipulation: The bolt must be pressed toward the left in addition to the normal bolt action turn and pull motions in order to cycle without binding on the barrel extension. Now that I've found the movement that works, it cycles properly both with a cocked trigger, and against a fired trigger to re cock it. I found this to be true on both uppers. Previously posted by PreacherOfGadget...might help? The cam pin absolutely is impacting the surface. I rounded the corners of the cam pin head on a grinder after taking this picture to reduce this issue. After doing that, I also stopped having issues with the carrier occasionally catching when I tried to cycle the gun while upside down. I think this platform would benefit from cam pin with a rounded or heavily-radiused rectangular head. |
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Just received my upper/bolt kit and can confirm that there's no gas block sleeve. Did notice that the "tail" of the bolt carrier doesn't protrude a huge amount from the back of the upper when the bolt is in the rearward position. Upthread I thought I remembered someone mentioning chopping it off, so that this upper can function on a lower with a folding stock. Has anyone tried this yet? |
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Originally Posted By Burnsome-: Previously posted by PreacherOfGadget...might help? The cam pin absolutely is impacting the surface. I rounded the corners of the cam pin head on a grinder after taking this picture to reduce this issue. After doing that, I also stopped having issues with the carrier occasionally catching when I tried to cycle the gun while upside down. I think this platform would benefit from cam pin with a rounded or heavily-radiused rectangular head. Originally Posted By Burnsome-: Originally Posted By ELittlefield: With additional dry fire and manipulation: The bolt must be pressed toward the left in addition to the normal bolt action turn and pull motions in order to cycle without binding on the barrel extension. Now that I've found the movement that works, it cycles properly both with a cocked trigger, and against a fired trigger to re cock it. I found this to be true on both uppers. Previously posted by PreacherOfGadget...might help? The cam pin absolutely is impacting the surface. I rounded the corners of the cam pin head on a grinder after taking this picture to reduce this issue. After doing that, I also stopped having issues with the carrier occasionally catching when I tried to cycle the gun while upside down. I think this platform would benefit from cam pin with a rounded or heavily-radiused rectangular head. I'll do my live fire testing before making a decision. Thanks though. |
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Originally Posted By LnWlf: The head of their sales department told me they won’t be offering the upper receiver and bolt as a standalone product for sale I’m hoping they change their mind, I’d love to do a build Originally Posted By LnWlf: Originally Posted By PreacherOfGadget: Care to provide any reasoning for that line of thought, other than general pessimism? Inquiring mind would like to know. Given that they could probably sell the combo carrier+handle+upper+rear plug for $200-$250, and not have the assembly cost (in addition to barrel, bolt, muzzle device), I'd think it'd be a profitable decision to make at some point. The head of their sales department told me they won’t be offering the upper receiver and bolt as a standalone product for sale I’m hoping they change their mind, I’d love to do a build Reading back through this thread, this post was one month ago today. My, how things change quickly. |
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Originally Posted By ELittlefield: My 16" 450 upper, and build kit and barrel for 300 arrived today. I built the 300 with a handguard I already had, and a random low profile gas block flipped front to back. It did NOT come with a sleeve/collar. The complete upper did come with a collar. Both uppers catch the bolt in the locking lugs when I attempt to unlock the bolt. The bolt has to be wiggled "just so" that the bolt body can be retracted. I don't know if that will smooth itself out, or if something will need to be done such as rounding the rear of the bolt lugs. It's little things like this that make me want to wait until the bugs are worked out before ordering one of these uppers. |
| 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. |
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 !!!
| I guess I’m spoiled with my TROMIX, TJ, and Paladin items because they never need a break in period. They just work out of the box, so I was hoping these uppers would not need an extensive break in period. Obviously that was wishful thinking for a sub $200 upper/bolt combo. Like another guy said, I think I’ll wait a bit to see just how much break in these things need before they work without fiddling with them. It sounds like they need some judicious and careful stoning to make them halfway smooth right now. |
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I've been working up some steps to smooth out the cycling on this upper. I was working on keys to smooth, silent cycling, but a side effect of one step is the carrier rotates just a hair further during retraction, so the bolt doesn't catch as often. I've had fewer issues with the bolt catching since I implemented these. Here's the key: my mod options expand the screw heads/charging handle base width until they're larger than the base of the charging handle, but only slightly. When being retracted, this pushes the charging handle upward more than the original design does, rotating the bolt just a bit more. I'm playing around with methods, and here's what I tested so far: 1) Electrical tape wrapped around the head of the bolts holding on the handles. It works, but wears fast. Starts wearing notably around 50 to 60 cyclings. Cheap, easy to keep on hand, but a becomes maintenance. 2) Rubber washer replacing lock washers. The ones I've tried are a little too big and would require customized trimming. They should work, but would require modification. 3) Replace the lock washers with 1-2 undersized o-rings, and tighten until they expand a little larger than the base of the charging handle. This allowed easy tweaking by tightening/loosening the screw. I intend on testing several layers of shrink tubing around their heads, and possibly nylon washers, and I may find other size rubber washers to try. I'll post a list of my modifications when they're all ready, but wanted to toss this advice out there since it addressed this topic. Because I have a nice Tromix bolt, I'm inclined to leave it alone, but if the issues with the bolt lugs hanging up, I may consider the slightest of rounding to the appropriate rear edges of bolt lugs. My issues with the lug catching are infrequent with the above mods, but not gone completely. |
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Originally Posted By TheRat: Upthread I thought I remembered someone mentioning chopping it off, so that this upper can function on a lower with a folding stock. Has anyone tried this yet? Yes. I have. You can see my build above -- only difference is I cut my carrier down now. Pics coming of modification along with pros-cons that I've noticed while working with it. Doesn't retract at all past the end of the receiver now. |
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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.  " />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. |
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Ran about 15 rounds before the range got busy and had to work. Agreed the bolt is forward. I'm sure someone will have a fix for that sooner or later. The upper is sensitive to the OAL (I think), when I get home I'll gauge a round. I was having difficult chambering with like l some reloads. I thought it was the gun remembering some comments here. Switched to 77gr OTMs from PSA and it shot smooth as butter. Accuracy at 50yds was better with the reloads tho. I'm going to need to tighten the upper/lower engagement. Too much wobble for me. Overall I like this setup very much. Getting a 300bo barrel soon. Attached File I added a rab-ad for ease of transport and a luth-ar stock. |
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I'm gonna go back to my experimenting before I post again, but a thought: before going after bolt lugs, what about just taking a little bit of material off the left side (as viewed from the rear) of the carrier and cam pin, so the carrier rotates further? That is the limiting factor on rotation, right? The carrier key comes out easy -- the bolts aren't even loctited in. Not advising anything at this point, but thought I'd drop the line of thought out here in case other thinkers may think thoughts improving on that thought line o' mine. |
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Originally Posted By PreacherOfGadget: I'm gonna go back to my experimenting before I post again, but a thought: before going after bolt lugs, what about just taking a little bit of material off the left side (as viewed from the rear) of the carrier and cam pin, so the carrier rotates further? That is the limiting factor on rotation, right? The carrier key comes out easy -- the bolts aren't even loctited in. Not advising anything at this point, but thought I'd drop the line of thought out here in case other thinkers may think thoughts improving on that thought line o' mine. I think I'm going to stone some edges and the bottom slope of the carrier to smooth the bolt travel a little. |
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Originally Posted By TNRonin: Agreed the bolt is forward. I'm sure someone will have a fix for that sooner or later. [...] I'm going to need to tighten the upper/lower engagement. Too much wobble for me. [...] Agreed on the wobble and the forward nature of the handle. Even bringing it back like 1.5"-2" via an alternate charging handle design would be greatly helpful. I'm 6'1" and it's at the limit of my comfort on my setup. The wobble bugs me too. I have mine on an FM Ranch lower -- no tensioning screw available or possible, and those wedges aren't an option either. I'm determined to figure something out, as I'd prefer not to resort to strips of electrical tape between the receivers, functional as it is. |
| Just a thought…some have mentioned the possibility of rounding the edges of the cam pin head, to make it more round than rectangular. What about the POF roller cam pin (https://www.pof-usa.com/product/roller-cam-pin/)? Would this do the same or maybe a bit better for functionality than trying to grind the factory cam pin? |
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Originally Posted By PreacherOfGadget: Agreed on the wobble and the forward nature of the handle. Even bringing it back like 1.5"-2" via an alternate charging handle design would be greatly helpful. I'm 6'1" and it's at the limit of my comfort on my setup. The wobble bugs me too. I have mine on an FM Ranch lower -- no tensioning screw available or possible, and those wedges aren't an option either. I'm determined to figure something out, as I'd prefer not to resort to strips of electrical tape between the receivers, functional as it is. I wonder if there is any nylon tubing that could be used to placed in the front and rear lugs for the pins to reduce the hole diameter. I may try some aluminum from a can. If that works I'll CA glue them in place. |
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Originally Posted By TNRonin: I think I'm going to stone some edges and the bottom slope of the carrier to smooth the bolt travel a little. I polished the bottom of the carrier up to 3k grit sand paper. I did the same to the hammer face that makes contact. I took carrier apart completely and polished to 3k grit. I polished sides of the key to 3k grit, and the cam pin, the corners of which I ground to have a more generous radius. I took a file to sharp edges around the base of the charging handle, to reduce wear. Then I polished the sides of that, too. On the charging handle, the bottom edge that is perpendicular to the bore next to the rear screw -- the bottom edge of the pocket -- round it slightly, as it can catch on the receiver at the front of the pocket. I also cut the wings off the back, so it doesn't reach the face of the buffer. A little lube, and it just so slick. |
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Originally Posted By PreacherOfGadget: I polished the bottom of the carrier up to 3k grit sand paper. I did the same to the hammer face that makes contact. I took carrier apart completely and polished to 3k grit. I polished sides of the key to 3k grit, and the cam pin, the corners of which I ground to have a more generous radius. I took a file to sharp edges around the base of the charging handle, to reduce wear. Then I polished the sides of that, too. On the charging handle, the bottom edge that is perpendicular to the bore next to the rear screw -- the bottom edge of the pocket -- round it slightly, as it can catch on the receiver at the front of the pocket. I also cut the wings off the back, so it doesn't reach the face of the buffer. A little lube, and it just so slick. Attached File That's how I handled transport. |
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Originally Posted By VTD: This isn't to scale because I'm not at home to measure right now but I think I'll print something like this to see if a simple bracket to relocate the bolt handle rearward is feasible without binding. https://www.ar15.com/media/mediaFiles/26478/Screenshot_2025-03-08_150751_jpg-3485218.JPG |
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Originally Posted By VTD: This isn't to scale because I'm not at home to measure right now but I think I'll print something like this to see if a simple bracket to relocate the bolt handle rearward is feasible without binding. https://www.ar15.com/media/mediaFiles/26478/Screenshot_2025-03-08_150751_jpg-3485218.JPG That’s awesome. Standing by to see how it works out! |
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Originally Posted By TNRonin: And that's how it's done! Originally Posted By Hijo202: That's awesome. Standing by to see how it works out! To scale. Just need to figure out nut and bolt sizes so I can inset a few hex shapes. Attached File |
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Originally Posted By PreacherOfGadget: Agreed on the wobble and the forward nature of the handle. Even bringing it back like 1.5"-2" via an alternate charging handle design would be greatly helpful. I'm 6'1" and it's at the limit of my comfort on my setup. The wobble bugs me too. I have mine on an FM Ranch lower -- no tensioning screw available or possible, and those wedges aren't an option either. I'm determined to figure something out, as I'd prefer not to resort to strips of electrical tape between the receivers, functional as it is. Old school trick, o rings around the takedown and pivot pin lugs on the upper. That or bedding them with RTV. Easily removable, oil resistant, but firm enough to remove slop. I’ll be getting one in the future and trying to mod it to work with my folding no buffer tube lower. A lightweight bolt action upper for hunting has my attention. |
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I'll have to find some thinner O-rings if that'll work. I've had uppers where that trick worked with the ones I have, but this particular upper-lower pairing is tight enough I can't close the receivers with any of the o-ring varieties I have on hand. ETA: @VTD that looks cool. If you're machining that, if it's possible, you might want to inset the area where the charging handle attaches so that pushing forward or backward the force is handled mostly by the machined parts and not the fasteners. |
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Originally Posted By Hijo202: Just a thought…some have mentioned the possibility of rounding the edges of the cam pin head, to make it more round than rectangular. What about the POF roller cam pin (https://www.pof-usa.com/product/roller-cam-pin/)? Would this do the same or maybe a bit better for functionality than trying to grind the factory cam pin? Was thinking the same thing. Might be worth a try |
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Originally Posted By PreacherOfGadget: I'll have to find some thinner O-rings if that'll work. I've had uppers where that trick worked with the ones I have, but this particular upper-lower pairing is tight enough I can't close the receivers with any of the o-ring varieties I have on hand. ETA: @VTD that looks cool. If you're machining that, if it's possible, you might want to inset the area where the charging handle attaches so that pushing forward or backward the force is handled mostly by the machined parts and not the fasteners.   Good thinking. I'm just going to 3d print something for now to see if it will work. Attached File The same thing could probably be accomplished with a simple bar with some holes drilled in it and some bushings for spacing and bolt lock up. |
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Originally Posted By VTD: Good thinking. I'm just going to 3d print something for now to see if it will work. https://www.ar15.com/media/mediaFiles/26478/extender3_jpg-3485340.JPG The same thing could probably be accomplished with a simple bar with some holes drilled in it and some bushings for spacing and bolt lock up. |
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Originally Posted By TNRonin: Realizing this is just the first iteration, how long is that arm going be? The whole thing is a little over 3". There aren't any clearance issues to the rear so it could really be as long as you wanted. I have a feeling that the sideways force is going to make things bind up a bit. Might be a non-starter. Fun to print and play with though. |
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Originally Posted By VTD: it will move the bolt handle back 2". The whole thing is a little over 3". There aren't any clearance issues to the rear so it could really be as long as you wanted. I have a feeling that the sideways force is going to make things bind up a bit. Might be a non-starter. Fun to print and play with though. |
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Bolt catching issues: ***FACEPALM*** Of course even a bolt well-machined and painstakingly finished for perfect feeding and extraction is designed to rotate counterclockwise when going in and clockwise when coming out. The bolt in this BCA upper rotates the opposite direction. It's the opposite rear edge of the lug that would be rounded for smooth operation in a semi-auto configuration. If any rear edges on the bolt have been smoothed, radiused, or chamfered to improve or "enhance" feeding and extraction, it's likely useless here, unless they did both sides equally... *shrug* Some issues of adaption. I'm starting to think *carefully* addressing the rear edges on the bolt might be the best way to ensure there's no catch on extraction. @VTD, this is gonna sound picky, but I have a thought on your extension design. The area where it interfaces with the carrier -- the rear section that actually presses against the receiver cutout -- I have a thought. Change the geometry of that face a far enough out that an expansion can clear the inset in the carrier. Give it more of a flat face with a rounded corner than a half-circle front. The additional surface area should help hold the bolt closed. There may be limit imposed by the cutout geometry too, but a flat rear interface would spread out the rearward force on the receiver, which is easy to apply as you're cycling if one is suffering from a touch of adrenaline. It should improve lockup when closed and reduce marring of the top edge of the cutout from use. |
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Originally Posted By PreacherOfGadget: Bolt catching issues: ***FACEPALM*** Of course even a bolt well-machined and painstakingly finished for perfect feeding and extraction is designed to rotate counterclockwise when going in and clockwise when coming out. The bolt in this BCA upper rotates the opposite direction. It's the opposite rear edge of the lug that would be rounded for smooth operation in a semi-auto configuration. If any rear edges on the bolt have been smoothed, radiused, or chamfered to improve or "enhance" feeding and extraction, it's likely useless here, unless they did both sides equally... *shrug* Some issues of adaption. I'm starting to think *carefully* addressing the rear edges on the bolt might be the best way to ensure there's no catch on extraction. @VTD, this is gonna sound picky, but I have a thought on your extension design. The area where it interfaces with the carrier -- the rear section that actually presses against the receiver cutout -- I have a thought. Change the geometry of that face a far enough out that an expansion can clear the inset in the carrier. Give it more of a flat face with a rounded corner than a half-circle front. The additional surface area should help hold the bolt closed. There may be limit imposed by the cutout geometry too, but a flat rear interface would spread out the rearward force on the receiver, which is easy to apply as you're cycling if one is suffering from a touch of adrenaline. It should improve lockup when closed and reduce marring of the top edge of the cutout from use. |
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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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BCA bolt action upper for $350? (Page 4 of 21)
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