dealing with hammer follow

[NCPatrolAR]

I'm running into a problem with my 9mm AR and figured someone here would have an idea of what is going on. I currently use an Oly/Sten mag setup and have great success with it until recently. A few months ago I started expereincing hammer follow resulting in strange things happening. I've placed the upper and 3 different lowers and still have the same problem. It doesnt occur every time the trigger is pulled; just maybe once or twice per mag. Anyone have an idea what might be causing this?

[C4IGrant]

Just so I am following, you have tried your upper on three different lowers (all with different trigger groups) and you are getting burst?


C4

If that's the case then I'm 100% confident it's a bolt/firing pin problem........If in fact this was on 3 different lowers with 3 different fire control groups and kept doing what it is doing.

That is what I was getting at. The issue cannot be with the Trigger group.


We also might want to be careful about talking about this subject in public after what we have seen the ATF do.


C4

[Robb Jensen]

It could be that the bolt isn't pushing the hammer all the way down and not allowing the disconnector to catch it.

NCpatrol are you using a non notched hammer or a 9mm hammer?

[NCPatrolAR]

Just so I am following, you have tried your upper on three different lowers (all with different trigger groups) and you are getting burst?

Correct. I initially had it on a gun with an LMT 2 stage in it and initially encountered the problem. I swticthed to a lower with a CMC trigger pack (single stage) and encountered it a lot. Finally went to a gun with a standard LPK and still experience it from time to time. It is less in this final setup; but still there.

The issue cannot be with the Trigger group.

Could it be a buffer/buffer spring issue?

We also might want to be careful about talking about this subject in public after what we have seen the ATF do.


C4

No sweating that. I worked daily with several agents and dont plan on loaning out my gun to someone "new" to ARs.

[NCPatrolAR]

NCpatrol are you using a non notched hammer or a 9mm hammer?

Standard hammer in the factory LPK. Appropariate hammer in the other two setups.

Think it might be the hammer?

[Robb Jensen]

Standard hammer in the factory LPK. Appropariate hammer in the other two setups.

Think it might be the hammer?

If using a notched AR15 hammer the bolt may not be pushing the hammer down into the disconnector allowing the disconnector to grab the hammer. An un-notched M16 type hammer (with the sear tail bobbed off) might allow the bolt to be pushed far enough down.

Non notched AR15 hammer.

[NCPatrolAR]

would I get the same results if I went with a 9mm hamme?

[Robb Jensen]

would I get the same results if I went with a 9mm hamme?

A 9mm hammer should fix it. Some are rounded at the top of them. FWIW Colt full auto submachineguns have standard M16 full auto hammers (shaped like mine but they have the sear tail), they don't use special 9mm hammers.

[NCPatrolAR]

thanks... might grab a RRA hammer and see if that solves my problems

[C4IGrant]

A 9mm hammer should fix it. Some are rounded at the top of them. FWIW Colt full auto submachineguns have standard M16 full auto hammers (shaped like mine but they have the sear tail), they don't use special 9mm hammers.

Agree. A 9mm hammer will fix the issue.


C4