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idolized
08-20-2011, 1:34 PM
Hey all, I finished my AR-15 build a while ago but I haven't taken it to the range yet (waiting for the next gun show to stock up on some bullets). Anyways, since I'm going to be taking it out and shooting it soon there was one concern that I had with it.

It seems that the bolt carrier does not lock into place. To try to clarify.. if you were to separate your upper from your lower and take the bolt carrier group/charging handle out and put it back together... your bolt carrier along with your charging handle would both lock into place, correct? and if you were to point them to the ground they would not fall towards the ground since they are locked right? because on my Adams Arms upper the bolt carrier will slide back only being stopped by the end of the charging handle. The bolt carrier sticks out of the upper receiver by about a 1/3 of an inch.

So not really sure if this is normal and I'd rather hear some of your opinions to figure if this is even safe enough to fire.

*edit* Just tried manually loading a round and pushing in the bolt carrier behind it... the bolt carrier sticks out and doesn't lock in.

Plisk
08-20-2011, 1:48 PM
Pictures may help.

Shellshocker66
08-20-2011, 2:06 PM
Normally there is only one way to get the bolt and charging handle to go in correctly. Take them out again, make sure it's lubed up well (bolt and charging handle, refer to the web for how to lubricate) and put it back in.

Pull back charging handle and push up the bolt catch and see if it locks.

Pictures would help a lot.

More will chime in and I'm a newb myself to the ar platform, but at first I was trying to put the bolt in backwards and wondering why it was not working :) .

97F1504RAD
08-20-2011, 2:07 PM
Are you running a regular DI/BCG with the Adams Arms Piston kit? Don't you need a BCG that is for the piston setup. And if you have that type of BCG do they sell kit for the various barrel setups you know carbine vs mid length vs rifle and do you have the correct kit for your rifle.

And yes pictures would be helpful for us to see what is going on.

mydogsmonkey
08-20-2011, 2:14 PM
thats normal, nothing wrong with it. The only thing locked in place is the charging handle, the bolt carrier will fall out if you didn't have a charging handle in there, you pushed the carrier in and tilted the upper receiver by itself. the spring is the only thing keeping it in place. there is a bit of tension sometimes because of the camming action of the bolt carrier but otherwise it sounds normal, just shoot it

idolized
08-20-2011, 2:16 PM
Sorry at work right now but I'll definitely have the pics up as soon as I get the chance. But pretty much the bolt carrier won't go down and lock in a round or lock itself without a round chambered... as for the setup it is a complete Adams Arms piston upper so it has everything set up for its piston.

97F1504RAD
08-20-2011, 2:55 PM
thats normal, nothing wrong with it. The only thing locked in place is the charging handle, the bolt carrier will fall out if you didn't have a charging handle in there, you pushed the carrier in and tilted the upper receiver by itself. the spring is the only thing keeping it in place. there is a bit of tension sometimes because of the camming action of the bolt carrier but otherwise it sounds normal, just shoot it

Nope it's not normal.

If you read his last line. He says that the BCG is not going in all the way in as it should.

mydogsmonkey
08-20-2011, 3:08 PM
my bad misread

are all the gas piston parts aligned correctly? I know in a DI system, if the gas tube isn't centered, the bolt carrier won't close, make sure the barrel nut or whatever holding it all straight it perfectly lined up to the hole on the receiver, and make sure all the gas piston parts(which i'm not familiar with) are all inline.

GILMORE619
08-20-2011, 3:34 PM
I have a Adams arms 7.5 gas piston upper on a AR pistol and it does the same thing the OP describes. It fires and functions without any problems

G-forceJunkie
08-20-2011, 4:58 PM
I don't know if the piston system is different. I suspect it is in the the piston rod may be spring loaded so it presses on the carrier at all times? In which case, when the upper is removed, and the buffer and recoil spring are not supplying forward "push", the bolt and carrier may not stay all the way forward and locked when pushed in by hand. In a DI system, it is possable for the BCG to fall out if you tilt the upper up. The only thing holding it locked in position is the friction. If the carrier is heavy enough, and the friction of the gas rings and cam pin in its slot are light enought, the carrier will go rearwards, unlocking the bolt, and letting it fall out the upper. Usually, closing the dust cover will help hold the carrier in place if your worried about it falling out while the upper is removed from the lower.

dieselpower
08-20-2011, 5:15 PM
Pay close attention to how she handles the BCG.... She's been taught well

irykjLjuKo8

sacshooter1
08-20-2011, 5:21 PM
Adam's Arms BCGs have a spring where the gas rings normally would be. The springs push the BCG out of the receiver a bit when you take the upper and lower apart. It is normal for that set up. I have one, it does the same thing, and it shoots fine.

97F1504RAD
08-20-2011, 5:34 PM
Adam's Arms BCGs have a spring where the gas rings normally would be. The springs push the BCG out of the receiver a bit when you take the upper and lower apart. It is normal for that set up. I have one, it does the same thing, and it shoots fine.

Nice to know.

cvx5832
08-20-2011, 5:42 PM
If it's anything like the piston bcg like on the Stag 8, it will not stay in the forward-most position without the action spring/buffer pushing against it, or by manually pushing it forward. There is a spring between the bolt and bcg (which doesn't exist in DI systems) that keeps the bolt in the forward position. Stag says it is there for stability.

And at least on Stag's implementation of the piston design, they use a standard bolt with the gas rings removed. This makes it move about very easily especially when oiled. So with a spring keeping the bolt in the forward (unlocked) position, the bcg WILL slide out as you describe when the muzzle is tilted up.

On a side note, and as already mentioned above, the gas rings on DI systems keep the bolt from clanking fore and aft, at least not easily. This keeps it in battery, and in turn keeps your bcg from sliding out.

cvx5832
08-20-2011, 5:58 PM
Is that your kid? Very refreshing to see. I started young too, and nowadays don't seem to see more parents passing on the fun of firearms to their kids anymore. Maybe it's just California, but other places I've lived in seem the same way.

It's sad, really. Because with proper training, having a firearm in the house is no more dangerous than walking the dog. But I'm preaching to the choir.


Pay close attention to how she handles the BCG.... She's been taught well

irykjLjuKo8

idolized
08-21-2011, 5:07 PM
I have a Adams arms 7.5 gas piston upper on a AR pistol and it does the same thing the OP describes. It fires and functions without any problems

Thanks everyone for your replies and insight. I guess it could be normal but it seems like without the bolt carrier locking all the way in, the hammer wouldn't be hitting the firing pin correctly. I'll definitely give Adams Arms a call and get this figured out and give everyone a heads up on what they say.

idolized
08-21-2011, 5:08 PM
Pay close attention to how she handles the BCG.... She's been taught well

irykjLjuKo8

Seen this a while back, pretty impressive stuff!

sacshooter1
08-21-2011, 5:30 PM
Thanks everyone for your replies and insight. I guess it could be normal but it seems like without the bolt carrier locking all the way in, the hammer wouldn't be hitting the firing pin correctly. I'll definitely give Adams Arms a call and get this figured out and give everyone a heads up on what they say.

The BCG will lock into the locking lugs when the upper and lower are together. The buffer spring will push the BCG into place. The spring is there to prevent cam pin wear.