ar bolt problem

[pulserifle99]

I have a Cmmg 20" upper ,i have had for sometime now, on a stag lower. I havent used my ar for some time, and when i went to the range i was having some problems with me bolt. When It try to strip a round from the magazine it the bolt doesnt seem to have the strength to strip the round from the magazine so it jams up about half way into battery. When i pull the charging handle all the way back again it will strip that round out completely and go into battery. But when i try to extract the round manually there is a lot of resistance coming out of the barrel. And twice it went into battery but pushed the bullet into the casing. I didnt fire it because the problems started occurring from the beginning. Also it is not the mag because i tried different ones. I am also not riding the charging handle. Sorry about the size of the pics.

[SJgunguy24]

Did you clean your rifle after the last time you shot it? Has the B.C.G. been lubed? Most AR issues i've seen are cleaning related.

[pulserifle99]

I have cleaned it, and it has been lubed. That was one of the first thing i thought of

[SJgunguy24]

I have cleaned it, and it has been lubed. That was one of the first thing i thought of

Buffer tube and spring?

[pulserifle99]

still having the same problems, what worries me the most is that sometimes when it goes into battery the bullet will be pushed into the case!

[SJgunguy24]

Where is Lemoore? There is a guy who posts here named Randall, his calguns handle is AR15barrels. He's an AR whiz and he knows his s***. His website is the same name. The contact info says Mar Vista, I have no clue where that is but I would send my AR to him if I was running into trouble.

I'm an AK guy, my AR is more or less a novelty. I would trust Randall with my rifle, I think you'll find more who agree with me.

[Nessal]

I dont think its the buffer and spring because if it has enough force to push the bullet into the casing it has enough force to push the cartridge into battery. Did you check the feed ramps to make sure nothing is out of spec? My initial thoughts were the mags. Try swapping a lower. That way you can isolate the problem more clearly.

[NeoWeird]

Now the first thing that comes to mind is you mention you've had the upper for a while but say nothing about the lower. Is this an upper and lower that you have used in the past with success? Or is this a proven upper and lower it hasn't been used on yet?

[pulserifle99]

I don't have another lower to try. What is supposed to be the spec on the feed ramp? Ive had the same upper and lower since the beginning

[aplinker]

Where is Lemoore? There is a guy who posts here named Randall, his calguns handle is AR15barrels. He's an AR whiz and he knows his s***. His website is the same name. The contact info says Mar Vista, I have no clue where that is but I would send my AR to him if I was running into trouble.

I'm an AK guy, my AR is more or less a novelty. I would trust Randall with my rifle, I think you'll find more who agree with me.

He's going to look at the fact he hasn't shot the gun and tell him to stop playing with it at home.

[NeoWeird]

Ok, now this is important.

DO NOT LOAD AN AR-15 IN YOUR HOME WITH LIVE AMMO!

The AR-15 firing pin is a floating firing pin with no spring to retard it's motion. The firing pin actually stops when it hits the primer on EVERY cartridge loaded and it DOES dimple them. It is VERY possible (read: it was a problem in the past that needed to have drastic changes) to set off a round by cimply chambering it if the cartridge is loaded with a soft enough primer.

That said, you need to whip the **** out of the charging handle and let the thing fly home. If it jams then start working backwards. What things have you changed since you last used it? New ammo? New magazines? Different magazines? Did you lube it? Was it not lubed last time? Did you use grease instead of oil? Did you store it loaded? Did you field strip it and clean everything to ensure you didn't have residual powders and solvents cake onto the surfaces? etc etc etc

The pictures are not clear enough for me to really see what's going on, but IF the bullet is getting set back into the case, do NOT fire them or the gun and have it checked by someone who knows more about ARs than you do. That is clearly an indication od the bullet making contact with another surface, like the barrel extension, and that slight set back can be VERY dangerous.

[pulserifle99]

no, Its the same ammo I've always used, 62 grain lake city, the magazine is still the same 10rounder that ive had since i put the rifle together. i have field striped it before storing it, and it only sat for like 2 months. When i brought it out it still had some oil so I re-oiled it. And when i clean it i bust out the picks and scrape the lugs, bolt, ect.....

[aplinker]

How much has the rifle been shot? 100rds? 1k? None?

[pulserifle99]

I'd have to say a little over 1k rounds down the pipe since 06'

[aplinker]

I'd have to say a little over 1k rounds down the pipe since 06'

And it just started this or always did it?

Does the rifle jam when you're shooting?