Headspace Issue?

[paddle007]

It looks like I fell victim to the backyard AR builder. I traded some ammo for a 11.5 upper built with new components. I finally made it to Honey Island today. I was experiencing light primer strikes which became more frequent. Eventually the trigger stuck. Thought maybe I botched the hammer spring but when I disassembled it a loose primer hit the table top. I looked through my casings and luckily I found the one. Now I understand what happened. Light primer strikes with a misfire mixed with a heavily marked case and primer when it would fire = to much headspace. I'll contact the builder and see where this leads me.

 

[Win1917]

I'm not an AR guy, just thinking aloud. Are you sure the headspace issue and primer falling out are related? Reason I ask, if there is enough headspace to allow the primer to push all the way out, seems like the gun wouldn't fire at all. Wondering if you have a headspace issue along with worn out cases with loose primer pockets.

 

[paddle007]

The first indicator was light firing pin strikes. Every primer I examined with the FTF was a light strike. I never caught the heavy strike until examing the spent casings. I think the primer worked loose because of the headpace but did not fall out until the case was in the process or being extracted. I'm trying to check the headspace today. I suspect either the barrel or bolt to be at fault.

 

[AK shooter]

I didn't know ar's had headspace issues. It looks to be an ammunition problem.

 

[crazy_mike]

I didn't know ar's had headspace issues. It looks to be an ammunition problem.

i have heard of checking headspace, but nothing like what he is speaking of that is happening, you can read up on checking headspacing on ar15.com.

 

[Gator 45/70]

Yes, That's what i think it is...ammo related

I didn't know ar's had headspace issues. It looks to be an ammunition problem.

 

[Win1917]

Oops, I just realized this in the rifle forum and not the reloading forum. That's why I assumed these were reloaded cases hence the comment about loose primer pockets. OP, is this reloaded or factory ammo?

 

[Gator 45/70]

Are we looking at Lake City headstamped ammo here, I'm not seeing a crimp ?

It looks like I fell victim to the backyard AR builder. I traded some ammo for a 11.5 upper built with new components. I finally made it to Honey Island today. I was experiencing light primer strikes which became more frequent. Eventually the trigger stuck. Thought maybe I botched the hammer spring but when I disassembled it a loose primer hit the table top. I looked through my casings and luckily I found the one. Now I understand what happened. Light primer strikes with a misfire mixed with a heavily marked case and primer when it would fire = to much headspace. I'll contact the builder and see where this leads me.

 

[paddle007]

Fiocchi ammo FWIW and I've run lots of it before and never had an issue....until this build. With all the panic buying I can not find a source for a go-no-go gauge. I tried a different BCG today made by BCM. I stripped the bolts and stacked brass shim stock between the bolt, receiver and an unfired round. I only found a two thousanths difference with the BCM being tighter. I hope to run a few rounds through it tomorrow and inspect the casings. I don't expect a big difference but hopefully it will help. A bolt would be cheaper than a barrel. And yes I did remove the projectile and powder from the test cartridge. Anyone want to sell me that dusty set of gauges yyou have laying around?

 

[SGT_Kramer]

Seems like could be headspace. Wish you were closer I'd fix it. If you grab the front of the barrel and the reciver in each hand and try to twist can you get any movement at all? If so your barrel is just loose. I've actually seen guns new behind the counter at stores with loose barrels.

 

[paddle007]

I gave it a gentle tug today but tomorrow I'll secure it in a vice and put some pressure on the front sight and see if it moves. It's supposed to be an E.R. Shaw barrel and I would expect it to be within specs but you never know.
Thanks for the advice.

Seems like could be headspace. Wish you were closer I'd fix it. If you grab the front of the barrel and the reciver in each hand and try to twist can you get any movement at all? If so your barrel is just loose. I've actually seen guns new behind the counter at stores with loose barrels.

 

[SGT_Kramer]

Be careful with the vice. While holding the front sight in one hand and receiver in the other if you twist and have any movement at all even a little tiny big that is more than likely your problem. I'd suggest not putting many if any rounds through it though until you get it figured out. I've seen first hand a co-worker who is very lucky to have both his eyes. I wouldn't wish that on someone I hate.

 

[JWG223]

Might want to write this one off until you can get the correct gauges or find someone who can fix you up. Face/hands/arms aren't worth it.

 

[paddle007]

Have not found a No-Go gauge yet. FWIW there is no movement with the barrel and receiver. I "ran" six cartridges minus the projectile and powder today after installing the BCM BCG. Nice firing pin hits in the primer. Promising. I'm not in a big hurry other than wanting to define the problem so I can deal with the builder.

 

[paddle007]

Update. It was the bolt. I first tried another BCG on cartridges with only a primer. Nice deep strikes. Finally scored a field and No-go gauge and there is a definate difference between the bolts. Both were stripped for the test just to err on the side of caution. I also discovered the barrel was a Model 1 Sales and the caliber was not marked. The seller stated it was an E R Shaw. From what I've learned both manufactures can be dicey. I did a casting of the chamber and it was .223 Not what I wanted. Again to err with safety I ordered a BCM 5.56 Nato barrel which also has a smaller/lighter profile. I assembled the upper today with the new barrel and new bolt. Much better. Nice deep primer strikes and passes the NoGo test. Can't wait to run it again. Well, in all honesty there will be a little fear after the last close call.

Hey, anyone want to run my new setup for me ? I'll supply a few test rounds