I just helped my brother in law build his first ar. This is my third build and his first. Everything went together fine and when doing some testing we had a problem. When a round is chambered and then ejected the next live round will get stuck and the bolt will not close, the forward assist will not advance bolt and the bolt can not be pulled back. We had to seperate upper from lower and beat bolt out the back with wood. Switched mags and seemed to solve problem until we got to range and did live fire. With two rounds in 20 round mag ran well(sighting in). Ounce loaded with 10 rounds it gave us same problem. Bolt stuck. Sorry for long post but it is frustrating and I am just looking for any experiences that you may have had that are similar and any fixes.
Trouble with new AR build
- Thread starter psyork22
- Start date
- Status
Frankl03
Member
Some questions: What type of upper? What type of ammo? Was the rifle and bolt cleaned and lubed prior to firing? What type of mags are you using?
If you answer the above we should be able to help.
If you answer the above we should be able to help.
DoubleTapDrew
Member
Is it something like this?
http://home.comcast.net/~jesse99/AR_Carrier.html
http://home.comcast.net/~jesse99/AR_Carrier.html
Ok, when you say "build", what do you mean by that? Did you slap an upper and lower together or did you build it from the ground up from parts?
Was the problem that a round was getting stuck in the chamber or was the bolt getting stuck? Were these factory rounds?
Was the problem that a round was getting stuck in the chamber or was the bolt getting stuck? Were these factory rounds?
kwelz
Member
Can we find out Bullet type, magazine type, and Feed ramps?
OK I knew these questions would probably be coming I was just hopeful that this problem may not be dependent on alot of factors. Here it goes. It was a complete build, Spikes tactical lower with dpms LPK, The upper is an AR stoner, BCG is an AR stoner and the barrel is a 16" AR stoner. Free float Troy rail with a Troy low profile gas block. The initial mag we used was one that he had from Iraq and the one we used at the range was a Magpil 20 rnd P mag. We did clean and lube(lube also from his Iraq tour) The ammo was my reloads that I have shot hundreds with great success out of my bushmaster and stag builds. The O.A.L. is 2.260" max. I am not sure on feed ramps. I told him we would try some Remington UMC factory ammo next time he comes up. Thanks alot for all the responses.
Zerodefect
member
Skip the Rem UMC, all my guns hate that stuff.
I usually use Federal 55gn FMJ (Walmart) for troubleshooting.
I usually use Federal 55gn FMJ (Walmart) for troubleshooting.
OK, they were reloads that got stuck, right? I'm assuming that it was the load that were getting stuck and not the bolt. What sizing die are you using? What seating die are you using? Are you crimping? If so, are you crimping with the seater die? Are you sure that the shoulders aren't collapsed a bit on some of the rounds?
It's entirely possible that the Stoner barrel has a tighter chamber or tolerances that differ from your rifles. I'd suggest taking the rifle out and running some factory loaded ammunition through it.
It's entirely possible that the Stoner barrel has a tighter chamber or tolerances that differ from your rifles. I'd suggest taking the rifle out and running some factory loaded ammunition through it.
OK, they were reloads that got stuck, right? I'm assuming that it was the load that were getting stuck and not the bolt. What sizing die are you using? What seating die are you using? Are you crimping? If so, are you crimping with the seater die? Are you sure that the shoulders aren't collapsed a bit on some of the rounds?
It's entirely possible that the Stoner barrel has a tighter chamber or tolerances that differ from your rifles. I'd suggest taking the rifle out and running some factory loaded ammunition through it.
I use all LEE components and I do not crimp. I figured with all brand new AR parts and components on the build that it was probably the ammo. Everything functions fine when empty and no signs of wear so hopefully it is just ammo.
It's entirely possible that the Stoner barrel has a tighter chamber or tolerances that differ from your rifles. I'd suggest taking the rifle out and running some factory loaded ammunition through it.
I use all LEE components and I do not crimp. I figured with all brand new AR parts and components on the build that it was probably the ammo. Everything functions fine when empty and no signs of wear so hopefully it is just ammo.
GIJOEL
Member
Did you check the chamber with a go/no-go gage? If you plan on building any more AR's you might invest the $20 and get one just to be able to rule out ammo problems before you get to the range. You never know if a barrel didn't get the chamber cut perfectly, or a bolt face got cut just a little lop sided.
The issue of headspace did pop into my head, but problems with headspacing are almost unheard of with milspec parts. These Stoner parts, I believe, are some sort of Midway brand or something and have had no experience with them. I really don't know if they come headspaced or not.
I keep a no go gauge around, just to make sure that there isn't excessive headspace in a new build and to check worn bolts/extensions. If you can get your hands on a "go" gauge, you might want to check the headspace for being too tight.
Still, since you are loading with Lee dies, I don't know. I've heard of a few guys having to go with small base sizing dies, or dies that allow you to bump the shoulder back a bit more than the Lee dies allow for some rifles.
I use Lee dies myself and haven't had any problems with my rifles.
Still, I'm not clear on whether it was the bolt sticking or a round getting stuck in the chamber. Since you aren't having problem operating the action with no ammunition, I'm going to continue to assume that a round is getting stuck.
As has been said, look to the ammo. No offense meant here, but did you screw the sizing die in until it hits the shell plate and then an additional 1/4 to 1/3 turn?
When you got that last round unstuck, could you see a rub mark where it got stuck?
I keep a no go gauge around, just to make sure that there isn't excessive headspace in a new build and to check worn bolts/extensions. If you can get your hands on a "go" gauge, you might want to check the headspace for being too tight.
Still, since you are loading with Lee dies, I don't know. I've heard of a few guys having to go with small base sizing dies, or dies that allow you to bump the shoulder back a bit more than the Lee dies allow for some rifles.
I use Lee dies myself and haven't had any problems with my rifles.
Still, I'm not clear on whether it was the bolt sticking or a round getting stuck in the chamber. Since you aren't having problem operating the action with no ammunition, I'm going to continue to assume that a round is getting stuck.
As has been said, look to the ammo. No offense meant here, but did you screw the sizing die in until it hits the shell plate and then an additional 1/4 to 1/3 turn?
When you got that last round unstuck, could you see a rub mark where it got stuck?
GIJOEL
Member
I only advise the go/no-go gage to rule out poor manufacturing. My units armorer has had new bolts and barrels come in out of spec. While QC is getting better everyday, it is still unperfect.
Thanks for all the replies! I think the round was getting stuck not allowing the bolt to move. For those who suggest no go guage could you explain hoow to use them. I have seen them and am planning on getting one but unsure how to use them.
It isn't actually a "go/no go" gauge. They are two separate things. It's just a chunk of steel cut into the rough shape of a cartridge. When you put the "go" gauge into the chamber, you should be able to place the bolt into the extension and "lock" it into place by rotating it simulating the chambering of a round. If the bolt won't close on a "go" gauge, there isn't enough headspace. When you insert the "no go" gauge, you should either not be able to close the bolt, or at least feel some resistance when trying to close the bolt all the way that will prevent the bolt from closing all the way. In other words, headspace is OK, even if the bolt almost closes, but not quite. There is also a field gauge. I keep one of these in my shooting bag. It's a test of extreme headspace. If you insert this gauge in your chamber and your bolt closes on it, there is way too much headspace and impending doom.
I got mine from Midway or Brownells. Can't remember which. They are for .223 but have worked for me. Since they are for .223, I tend not to use the "no go" gauge and stick with the field gauge, but also use the "go" gauge. I believe that most people with a 5.56 would be better served by using the field gauge rather than the "no go" gauge, but in your case, it sounds like a "go" gauge might be in order.
I got mine from Midway or Brownells. Can't remember which. They are for .223 but have worked for me. Since they are for .223, I tend not to use the "no go" gauge and stick with the field gauge, but also use the "go" gauge. I believe that most people with a 5.56 would be better served by using the field gauge rather than the "no go" gauge, but in your case, it sounds like a "go" gauge might be in order.
- Status
