Thanks! Reading these threads fixed my issue

[c3k]

Folks,

I just built my first Grendel. 18" Alexander Arms, Adams Arms Piston kit (micro adjustable block), etc.

I used a standard lower parts kit. I was having failure of the bolt to lock after last round (6 different Elander magazines: all had same issue). Also, sometimes the bolt would close without feeding a round. Sometimes it would jam up against a misfed round.
Adjusting the gas did not fix the issue.

So... I read a little bit. I changed out my standard weight (3.0 oz.) carbine bolt and tossed in an H2 (4.5 oz.) from Primary Arms.

Presto Magicko! All my feed and other issues were fixed.

Just wanted to say a "thanks" to the community. Without having to post a thread, I was able to learn for others' issues and the advice offered to them.


Ken

[Jakal]

Well Congrats and good luck. Let us know how it shoots.

[LRRPF52]

External piston systems normally are mated with unusually heavy buffers because the gas acting on the piston cup or head causes instantaneous carrier inertia, which is bad for extraction so close to obturation.

Every company that has seriously tackled the external op-rod guns has used very heavy buffers to act as a rate reducer, and they are usually combined with heavier action/recoil springs.

[c3k]

External piston systems normally are mated with unusually heavy buffers because the gas acting on the piston cup or head causes instantaneous carrier inertia, which is bad for extraction so close to obturation.

Every company that has seriously tackled the external op-rod guns has used very heavy buffers to act as a rate reducer, and they are usually combined with heavier action/recoil springs.

That was EXACTLY what I meant to say.

In a serious vein, I've followed a LOT of what you've written. I'd like to say "thank you" for sharing some of your incredible depth of knowledge. I've gained a lot from it.

Thanks,

Ken