??? HELP??? Dec 27, 2012 20:41:31 GMT -8
Post by sergiomartinez on Dec 27, 2012 20:41:31 GMT -8
Dec 21, 2012 13:43:51 GMT -8 @sergiomartinez said:Let me try to help you out.
First forget about the gas system for a second.
Did you try with another lower that is known to work reliably in another AR? Yes
If you try this and it works then you know other place where you need to look at.
One could say your system is under-gassed but before we draw any conclusions we also need to make sure the lower, magazine or the buffer are not putting the brakes on the carrier group.
Everything that happens in fast motion one can replicate in slow motion as far as charging the rifle slowing and looking for any frictions. The bolt should be unlocking very easily w/o obstruction. I would test this without and with the lower on. We have done this as well.
Then a hammer spring that has excessive force with a hammer that is out of spec or full of machine marks or rough cuts is going to slow down that initial push (I have seen them).
So while it is logical to start at the port I don't think it is a dwell time issue and before getting into any conclusions it is logical to follow the gas forces but not only looking for where gas pressure might be missing due to leaking or not being there in the first place but look at the internals and make sure there is nothing there slowing the group.
Charging an upper should feel very smooth and uniform force w/o any spots where it feels harder or slowing due to friction or other forces.
Make sure the bolt lugs do not make contact with the magazine lips due to dropping the magazine or something else. Nope
An adjustable block is going to do little for you as normally you use them to reduce the amount of gas.
Try cycling the system with M193 LC nato rounds that are pretty hot. But a well tuned AR should cycle with anything, even PCM bonce that are very mild.
Try this ammo and try another lower. if you want to call me send me a PM and I will be happy to discuss with you. Everything can be fixed the issue is to identify first where the real root cause is.