AR Sponsor
Posted: 10/21/2015 6:56:44 PM EDT
|
I was waiting on a NiB bolt carrier group to arrive for my lightweight build that I posted the other day and it finally came in.
But now I have a problem. I dropped the BCG into the rifle to test it with my go/no-go gauges for headspace and it's not good. Neither the 223 or 556 "go" gauges would clear and the bolt will not engage. However, it chambers a live 223 round without an issue. I wish I had another BCG lying around to drop into the gun to see if it would pass the gauges. Any of you have issues with a Delton DTI light barrel not being chambered properly? It's stamped 556NATO and I purchased that brand, not only for it's affordability, but because I had read a review where a gentleman had tested a rifle they sent him and inspected the chambering to see if it was a true 556, which is was, according to his gauges. Now I'm regretting Loctiting the gas block set screws before checking the headspace on this rifle. I guess DTI will be getting their barrel back for not cutting the chamber deep enough. But what are the odds of the bolt being out of spec? I wish I had my digital caliper to measure the bolt lug. |
|
If it will chamber the ammo you are going to run, ignore the fact that it won't close on a go gage.
Excessive headspace is what you need to be worried about. Headspace that's only .0005" (half a thousandth) too short for the particular gage(s) you're using will prevent the bolt from closing on the gage but will still have plenty of clearance for properly sized cartridges. By the time the bolt mates to the barrel extension, the go gage will probably drop in. Joe |
|
Quoted:
I was waiting on a NiB bolt carrier group to arrive for my lightweight build that I posted the other day and it finally came in. But now I have a problem. I dropped the BCG into the rifle to test it with my go/no-go gauges for headspace and it's not good. Neither the 223 or 556 "go" gauges would clear and the bolt will not engage. However, it chambers a live 223 round without an issue. I wish I had another BCG lying around to drop into the gun to see if it would pass the gauges. Any of you have issues with a Delton DTI light barrel not being chambered properly? It's stamped 556NATO and I purchased that brand, not only for it's affordability, but because I had read a review where a gentleman had tested a rifle they sent him and inspected the chambering to see if it was a true 556, which is was, according to his gauges. Now I'm regretting Loctiting the gas block set screws before checking the headspace on this rifle. I guess DTI will be getting their barrel back for not cutting the chamber deep enough. But what are the odds of the bolt being out of spec? I wish I had my digital caliper to measure the bolt lug. You do realize that .223 Remington and 5.56X45 NATO have IDENTICAL chambers? It's the throat that's different, 5.56X45 has a longer leade before the projectile engages the rifling. Michiguns make a gauge the will check the throat. |
|
Quoted:
Did you remember to strip the bolt you used for the go gauge? You can't just drop in a bolt/bcg on a chamber gauge. It doesn't work like that. You have to take the ejector out and the extractor off. Both of which will interfere with a chamber gauge reading. Yes. And I've never really seen a difference between removing the ejector or anything. If that prevented a gun from functioning properly then we wouldn't be able to fire live rounds safely. It's still a NO-GO on the "GO" gauge. 
|
|
Quoted:You do realize that .223 Remington and 5.56X45 NATO have IDENTICAL chambers?
It's the throat that's different, 5.56X45 has a longer leade before the projectile engages the rifling. Michiguns make a gauge the will check the throat. Yes, I'm aware. I like redundancies. However, the "No-Go" gauges have different measurements on them between the two calibers even having the gauges being made by the same company. So, I want my rifles to clear Go/No-Go on both. |
|
Bolts have a .003” tolerance range.
I have found a number of barrel/bolt combos that failed the Go gage due to tolerance stacking with the bolts. I have bolts ranging from min to max tolerance so it is relatively easy to see if it is the bolt or the chamber. Ammo has a wide tolerance range. It is typically made so it will feed and function in a wide range of chambers. You can have a short chamber and never have a problem with typical ammo, but get ahold of ammo that is in the high end of the tolerance range and you can start having issues. Not necessarily a big deal at the range, but could lead to unintended consequences in a HD situation. |
|
Quoted:
Bolts have a .003” tolerance range. I have found a number of barrel/bolt combos that failed the Go gage due to tolerance stacking with the bolts. I have bolts ranging from min to max tolerance so it is relatively easy to see if it is the bolt or the chamber. I have five more BCGs that are Titanium Nitride that I can try out later, but they are across the state at the range in a safe. And, they're not M16 cut, just AR15. I was wanting the extra mass for felt recoil reduction. Between the chamber and the bolt, I am just not sure which one is off a tid bit that is causing the issue. I don't have a chamber gauge and my digital calipers are stored away with my woodworking equipment while I'm waiting to see what I'm going to be doing about graduate school(not sure where I could be moving to) |
|
Quoted:
Yes. And I've never really seen a difference between removing the ejector or anything. If that prevented a gun from functioning properly then we wouldn't be able to fire live rounds safely. It's still a NO-GO on the "GO" gauge. http://i42.photobucket.com/albums/e311/Blacktalons/Bolt.jpeg http://i42.photobucket.com/albums/e311/Blacktalons/No%20Go%20on%20-go-.jpeg Quoted:
Quoted:
Did you remember to strip the bolt you used for the go gauge? You can't just drop in a bolt/bcg on a chamber gauge. It doesn't work like that. You have to take the ejector out and the extractor off. Both of which will interfere with a chamber gauge reading. Yes. And I've never really seen a difference between removing the ejector or anything. If that prevented a gun from functioning properly then we wouldn't be able to fire live rounds safely. It's still a NO-GO on the "GO" gauge. http://i42.photobucket.com/albums/e311/Blacktalons/Bolt.jpeg http://i42.photobucket.com/albums/e311/Blacktalons/No%20Go%20on%20-go-.jpeg Do you also realize that the bolt carrier can affect the readings. You have to check with the bolt completely stripped AND out of the carrier. It also helps the accuracy if the barrel is out of the upper. |
|
Quoted:
Do you also realize that the bolt carrier can affect the readings. You have to check with the bolt completely stripped AND out of the carrier. It also helps the accuracy if the barrel is out of the upper. I use force and push the bolt carrier into the breech to engage. If it's not engaging, then it's not going to. It either works or it doesn't. This isn't my first build. The rest engaged properly without any issue and didn't have any feeding problems while firing. I checked those other rifles that I've built with the same method of using the bolt carrier (because that's how the gun works in action) and they ate the GO gauge and rejected the NO-Go gauge. This is just the first one that I've had one that had lugs not engage and lock into the breech. |
|
Quoted:
I have five more BCGs that are Titanium Nitride that I can try out later, but they are across the state at the range in a safe. And, they're not M16 cut, just AR15. I was wanting the extra mass for felt recoil reduction. Between the chamber and the bolt, I am just not sure which one is off a tid bit that is causing the issue. I don't have a chamber gauge and my digital calipers are stored away with my woodworking equipment while I'm waiting to see what I'm going to be doing about graduate school(not sure where I could be moving to) Quoted:
Quoted:
Bolts have a .003” tolerance range. I have found a number of barrel/bolt combos that failed the Go gage due to tolerance stacking with the bolts. I have bolts ranging from min to max tolerance so it is relatively easy to see if it is the bolt or the chamber. I have five more BCGs that are Titanium Nitride that I can try out later, but they are across the state at the range in a safe. And, they're not M16 cut, just AR15. I was wanting the extra mass for felt recoil reduction. Between the chamber and the bolt, I am just not sure which one is off a tid bit that is causing the issue. I don't have a chamber gauge and my digital calipers are stored away with my woodworking equipment while I'm waiting to see what I'm going to be doing about graduate school(not sure where I could be moving to) Without the right tools it is hard to tell how much it is off. My past experience would suggest that a bolt on the loose side will pass, but that is not guaranteed. Manufacturers who want the final headspace tight may not get what they want setting the initial headspace so any bolt will pass the Go gage. |
|
I've only had one that was difficult.
It was too "tight". The bolt would close, but it was a very snug closing on the go gauge. I had problems with occasional (even once is too much to depend on the rifle) primers blowing out of the cases and getting stuck in the receiver. Locked up the bolt one time, got down into the trigger/sear area another time and locked up the trigger, after it fired when I didn't pull the trigger (well, I pulled the trigger and nothing happened, I took the rifle off my shoulder, kept if pointed down range and sat down to take it apart and when I sat down the rifle fired - that'll make you look at things in a funny way.) I had a 20" build from a couple years previous that was very loose. The bolt would not quite close on a field gauge and was sloppy on the go gauge. I pulled it out of the safe and swapped bolts between the two (putting my brand new, hardly used NiB bolt in the 20" rifle I seldom shoot) and the 16" carbine has functioned flawlessly ever since with the same ammo. Every now and then, things just add up - to problems. |
| This is how check headspace on my new builds. The only thing this test shows me is if the bolt fully closes, nothing more, and nothing less. First I assemble two rounds, one 5.56, and one 223 without any gunpowder and no primers in them. Chamber the round with the charging handle, and safety on. Then I separate the lower receiver from the upper receiver. Turn the upper assembly upside down and shine a flashlight down the feed ramps to see if the bolt lugs are perfectly locked up with the barrel extension. I repeat this test with both rounds 2-3 times to make sure bolt fully closed every time. |
|
I simply want to make sure that the bolt lugs sit with their entire surface against the lugs on the barrel extension. That's the most important factor for me. Everything else I find out when I fire the rifle, reliability, ejection, feeding, and case examination. If those things don't show any problems, then the rifle is good to go for me.
https://en.wikipedia.org/wiki/Headspace_%28firearms%29#/media/File:Headspace.png |
|
Quoted:
You're more than welcome to pay $300 for a "name" BCG and another $300 for a "name" barrel that you're comfortable with to send people beneath you. I will be waiting. Quoted:
Quoted:
A no name bcg and Del Ton barrel out of spec....and we're surprised because? You're more than welcome to pay $300 for a "name" BCG and another $300 for a "name" barrel that you're comfortable with to send people beneath you. I will be waiting. The Irony, coming from someone who claims to have over a hundred guns, 6 gun safes, says bushmaster's are shit, Mossberg's are the shizzle, and doesn't know where he's going to move to after grad school. I mean to each their own, but I'd take a 870 over a 500 any day. |
|
Quoted:
The Irony, coming from someone who claims to have over a hundred guns, 6 gun safes, says bushmaster's are shit, Mossberg's are the shizzle, and doesn't know where he's going to move to after grad school. I mean to each their own, but I'd take a 870 over a 500 any day. Quoted:
Quoted:
Quoted:
A no name bcg and Del Ton barrel out of spec....and we're surprised because? You're more than welcome to pay $300 for a "name" BCG and another $300 for a "name" barrel that you're comfortable with to send people beneath you. I will be waiting. The Irony, coming from someone who claims to have over a hundred guns, 6 gun safes, says bushmaster's are shit, Mossberg's are the shizzle, and doesn't know where he's going to move to after grad school. I mean to each their own, but I'd take a 870 over a 500 any day. No, I didn't say I didn't know where I am moving after grad school. It's a matter of which MBA program I choose to go to across the country. You may not understand this, but that's not something you rush into since they can cost $100-120,000 for a degree. Take that Remington. I don't care. And I don't claim. It's just the way it is. You can worry about brand names all you want. I try new things. You should probably tell the forum to stop accepting money from Delton to advertise here too. |
|
This went off the rails quick.
Op, people are just asking questions to cover all possibilities. Unless you are tight with everyone who has already posted and they are familiar with all of your work, its hard to know what you've got or working with. You're coming off as way unreceptive to anyone else's advice and very defensive to everyone's questions. I hope you get it all squared away |
|
Quoted:
This went off the rails quick. Op, people are just asking questions to cover all possibilities. Unless you are tight with everyone who has already posted and they are familiar with all of your work, its hard to know what you've got or working with. You're coming off as way unreceptive to anyone else's advice and very defensive to everyone's questions. I hope you get it all squared away It's just that a lot of people like to just say "Well, You didn't buy the _____ so good luck." That's not productive. I haven't many suggestions, just "Hey, 556 and 223 use the same GO...." yes. That isn't helpful. I have the gauges and they are clearly marked with their measurement clearances. I am tired of the pissing contests. It's not productive. If you buy MEGA then "You should have bought AIM" or if you buy Aero then "You should have bought Seekins" etc etc etc. It gets old. I was mostly curious about the bolt being the issue. I will try out one of my titanium nitride bolts when I get to the ranch next time. I know better than to ask for general feedback from now on. For those that made sincere suggestions and advice, thank you. I'm done. Have a good weekend |
|
OP, I completely agree with the previous poster who said your most accurate headspace measurement will be with the barrel out of the upper and just a bare bolt. Not that it's quick, easy and fun to take that upper apart, but that will tell you if you're seeing a real problem or just a bunch of things getting in the way of your measurement. For example, bolt rings can cause false "resistance" with a brand new bolt and carrier (no matter how slick a fancy coating is supposed to be, those rings are supposed to be tight).
Checking headspace with a bare barrel and bolt is pretty easy. Hold the barrel in one hand, muzzle down. Drop the headspace gauge in the chamber (make sure it goes in straight). Now place the bolt in the barrel extension and see if it goes in far enough for the bolt to turn. If it does, that tells you everything you need to know. The bolt SHOULD close on a GO gauge, , but should NOT close on a NO GO gauge. As PFC pointed out, you can have a headspace "fail" with one bolt and "pass" with another due to bolt tolerances. There's a guy on the EE selling nice (no name) stripped bolts for $15 each delivered - I bought one precisely to have a spare bolt on hand JUST for testing headspace with. |
|
Quoted:
OP, I completely agree with the previous poster who said your most accurate headspace measurement will be with the barrel out of the upper and just a bare bolt. Not that it's quick, easy and fun to take that upper apart, but that will tell you if you're seeing a real problem or just a bunch of things getting in the way of your measurement. For example, bolt rings can cause false "resistance" with a brand new bolt and carrier (no matter how slick a fancy coating is supposed to be, those rings are supposed to be tight). Checking headspace with a bare barrel and bolt is pretty easy. Hold the barrel in one hand, muzzle down. Drop the headspace gauge in the chamber (make sure it goes in straight). Now place the bolt in the barrel extension and see if it goes in far enough for the bolt to turn. If it does, that tells you everything you need to know. The bolt SHOULD close on a GO gauge, , but should NOT close on a NO GO gauge. As PFC pointed out, you can have a headspace "fail" with one bolt and "pass" with another due to bolt tolerances. There's a guy on the EE selling nice (no name) stripped bolts for $15 each delivered - I bought one precisely to have a spare bolt on hand JUST for testing headspace with. Shouldn't you check headspace between chamber and bolt with the bolt you are going to be using with that particular chamber? |
|
Quoted:
I simply want to make sure that the bolt lugs sit with their entire surface against the lugs on the barrel extension. That's the most important factor for me. Everything else I find out when I fire the rifle, reliability, ejection, feeding, and case examination. If those things don't show any problems, then the rifle is good to go for me. https://en.wikipedia.org/wiki/Headspace_%28firearms%29#/media/File:Headspace.png We have cartridge and chamber specs so a max tolerance cartridge will work in a minimum tolerance chamber and vice versa. The only reliable way to check headspace is with headspace gages that are the proper spec for your chamber. I am not sure what you mean when you say you assemble a 5.56 and a 223 cartridge since for practical purposes the external case dimensions are the same. |
|
Quoted:
OP, I completely agree with the previous poster who said your most accurate headspace measurement will be with the barrel out of the upper and just a bare bolt. Not that it's quick, easy and fun to take that upper apart, but that will tell you if you're seeing a real problem or just a bunch of things getting in the way of your measurement. For example, bolt rings can cause false "resistance" with a brand new bolt and carrier (no matter how slick a fancy coating is supposed to be, those rings are supposed to be tight). Checking headspace with a bare barrel and bolt is pretty easy. Hold the barrel in one hand, muzzle down. Drop the headspace gauge in the chamber (make sure it goes in straight). Now place the bolt in the barrel extension and see if it goes in far enough for the bolt to turn. If it does, that tells you everything you need to know. The bolt SHOULD close on a GO gauge, , but should NOT close on a NO GO gauge. As PFC pointed out, you can have a headspace "fail" with one bolt and "pass" with another due to bolt tolerances. There's a guy on the EE selling nice (no name) stripped bolts for $15 each delivered - I bought one precisely to have a spare bolt on hand JUST for testing headspace with. Problem solved. Thanks guys. I'm not going to worry anymore about it. I just ordered a TiN bolt to try for fit and a second Del-ton bolt(since it's their barrel) to try for fit. Then I have parts for later builds (still have 9 receivers to go) Done |
|
LBishop,
I have a friend who works in the industry. She checks headspace on more weapons in a day than most of us will do in a life time. I asked her about this one day, and she said she switches bolts on roughly one out of ten barrels for headspace issues. I understand this doesn't help you any, but the number she gave is very very different than what this board tends to tell people, and much higher than what I had thought as well. |
|
Quoted:
LBishop, I have a friend who works in the industry. She checks headspace on more weapons in a day than most of us will do in a life time. I asked her about this one day, and she said she switches bolts on roughly one out of ten barrels for headspace issues. I understand this doesn't help you any, but the number she gave is very very different than what this board tends to tell people, and much higher than what I had thought as well. Thanks bud. I know a lot of people get caught up in brands and lionize them but that's just positive reinforcement where they disregard the negative occurrences they encounter and block them out of their mind. Every "You should have paid 10x more for this brand I like just like I did" guy here forgets that forums like these are filled with backlogs of documentation of failures and shortfalls of EVERY brand out there. Everyone is a master gunsmith when they join a gun forum. It's very hard to make things very exact every time, or even close to every time. It doesn't surprise me that your friend would have issues fitting bolts because being off by 1/10th - 3/10th the width of a human hair can throw it off. I used to make duckcalls by hand and it was hard enough working with 100ths of an inch, not 1,000ths of an inch, fitting wooden barrels snugly to metal bands without having to rely on adhesives. Guns would be even worse of a hassle to make pallet loads of. And it annoys me with <REMOVED- Warning sent - F> talking about "no name" gun companies making precision parts and that being the reason for issues. Every one of the "NAMED" companies were once "No Name" companies that built a following for whatever reason (finishing work or price). And these forum experts also ignore how incestuous industries like parts companies and gun companies are where they outsource work to "No Name" or other bands to produce material or parts for their company. They ignore that a lot of big companies use other companies to make their bolt carriers, receivers, and barrels for them and simply rebrand them. Or that trigger companies have other companies machine material for them. They confuse price with quality. High prices usually indicate that their production is very inefficient and they have entropy they;ve not dealt with by streamlining. Some companies have been around for half a century and have lower prices because they know what in the hell they are doing when it comes to production because they have been spending decades working contracted supplies to larger corporations that can't handle it in-house. Just because they cost less doesn't mean they're low quality. And just because they cost more doesn't mean they're better. A lot of it comes down to efficiency and the unit cost of production. When you turn out less volume and factor in the production cost then you have to sell it for more or you go bankrupt. Ferrari doesn't make nearly as many corvettes as Chevy and they cost a fortune because of it even though the Corvette has the same or better road performance all while costing 1/5th the price. I recently bought half a dozen "Name" drop-in triggers that were made by a partnering company that does the machining work for them. Instead of paying $180-200 a trigger, it's really half that. Oh well. Rant over. Thanks for your input. |
|
Quoted:
No, I didn't say I didn't know where I am moving after grad school. It's a matter of which MBA program I choose to go to across the country. You may not understand this, but that's not something you rush into since they can cost $100-120,000 for a degree. Take that Remington. I don't care. And I don't claim. It's just the way it is. You can worry about brand names all you want. I try new things. You should probably tell the forum to stop accepting money from Delton to advertise here too. Quoted:
Quoted:
Quoted:
Quoted:
A no name bcg and Del Ton barrel out of spec....and we're surprised because? You're more than welcome to pay $300 for a "name" BCG and another $300 for a "name" barrel that you're comfortable with to send people beneath you. I will be waiting. The Irony, coming from someone who claims to have over a hundred guns, 6 gun safes, says bushmaster's are shit, Mossberg's are the shizzle, and doesn't know where he's going to move to after grad school. I mean to each their own, but I'd take a 870 over a 500 any day. No, I didn't say I didn't know where I am moving after grad school. It's a matter of which MBA program I choose to go to across the country. You may not understand this, but that's not something you rush into since they can cost $100-120,000 for a degree. Take that Remington. I don't care. And I don't claim. It's just the way it is. You can worry about brand names all you want. I try new things. You should probably tell the forum to stop accepting money from Delton to advertise here too. If you have that many rifles why not try the bolt out of another rifle for comparison purposes? |
|
Quoted:
Shouldn't you check headspace between chamber and bolt with the bolt you are going to be using with that particular chamber? Yes and no. If the bolt you plan to use doesn't pass with that barrel, is it the bolt, or is it the barrel? Having a known in-spec bolt makes that an easy question to answer. If it turns out your chosen bolt isn't quite right for that barrel, you can go with a different one - before ever firing a shot. My first 300 Blackout barrel wasn't properly chambered, and because I wanted to be darn sure, I checked with two other bolts, just to be certain. Because I didn't want to have to spend a bunch of time messing with doing the detailed measurements to determine whether or not a bolt is in-spec for every bolt I ever come across, I bought a stripped bolt, did those measurements once, and now I have a standardized, in-spec, known good bolt to use to validate headspace measurements. |
|
I got one of the bolts I ordered delivered today. It's the standard phosphate bolt from Delton (ordered to match their barrel). The titanium bolt I ordered from brownells hasn't arrived.
The rifle is good to go now. The new bolt passes the gauges, so the headspace is good. The NiB bolt was just so slightly too tight. So, I guess I will be running a hybrid BCG with this barrel. It doesn't really bother me. 
|
|
Quoted:
NiB is a coating so the bolt would wind up having ever-so-slightly thicker lugs and an ever-so-slightly shallower face after the coating process. An in-spec bolt could be on the edge of being in-spec and then not be after the coating. Yeah, the nickel and titanium BCGs have similar coefficients but the NiB plating does seem to have more texture to it on this make than the TiN BCGs I have at the ranch. The BCG isn't bad and is nice quality, but it's admittedly not mirror polished. Smooth, but not as fine as the TiN ones I have. I've seen where people have had issues with different NiB BCGs from varying makers sluffing off a little plating and making for tight fitting issues until they used a wire brush to go over the edges with. I'm sure it was borderline on the upper end of being in spec and the plating had an issue. It's ok. I'm going to hold onto the bolt in the event that I get a barrel mounted that needs a tighter fit. Actually, seeing the photo on my computer instead of the phone, I can see what looks to be small little NiB flakes on the phosphate bolt lugs from having function tested it after swapping them out. It picked up the flakes left in the breech |
AR Sponsor