[Lt.Dan]

When shooting and I get to the last round my bolt doesn't lock back. First thought it was the mags, but after I went through every one and none of them locked it back I'm figuring it's the gun. It's a DPMS and I have tried many different kinds of mags. Even when I shoot slow and I am taking my time it still doesn't work. Could the bolt lock spring be too strong and holding the mag follower down? Any input is appreciated.

 

[DESOTO]

How long is the barrel?


1.Incorrect spring in the mag catch.
2.BAD lever. This part has been known on some rifles to cause the bolt not to lock back on an empty mag.
3.Buffer system.
4. Gas issue. Check rings. (what kind of rounds are you using?)

 

[Lt.Dan]

16" barrel.
Factory mag release and bolt catch.
What could be wrong with the buffer? Spring if fine.
Both factory and reloaded rounds. 55gn up to 75gn.

Once in a great while it will lock back while shooting slooow. not very often tho.

 

[captain-03]

Is this a NEW problem -- was the rifle firing OK with the same type ammo and mags in the past?

 

[Myers]

Have you tried some full power 5.56?

It's possible that it's recoiling enough to feed, but short stroking just enough not to engage that bolt catch on the last round.

 

[DESOTO]

If the spring is not set correctly, it will allow for another round to be loaded, but not enough for the bolt to lock back. Does that make sense?

 

[Lt.Dan]

I have had this problem ever since I've owned the rifle. I have tried full power rounds as well. Maybe I will try snipping a few coils off the bolt lock spring.

 

[walkiahgunman]

A buddy of mine had the same problem with his DPMS. Turned out to be the buffer spring, it was too stiff. He clipped a coil at a time until he got it right. No problems since. We found out the problem after putting the spring out of my M&P in it, worked fine with mine. You could tell a difference in the springs just by the stiffness in the charging handle, and it was a big difference in the two.

 

[Lt.Dan]

Ok cool. I'll have to try that. Thanks for the info.

 

[sigma74216]

Take an empty mag and cycle the bolt with your hand if it catches when manualy cycling. Then it's probably the buffer spring if not then probably bolt catch spring.

 

[Lt.Dan]

Yea it catches by hand. Il take a coil off and put some rounds through it. Thanks everyone for the help.

 

[DESOTO]

Glad we could help... Let us know if it takes care of the problem..

 

[osucowboy8]

Yea it catches by hand. Il take a coil off and put some rounds through it. Thanks everyone for the help.

What buffer do you have in it? Is it the heavy buffer? It may just be that you need to try a standard buffer.