hi to everyone.    I recently finish putting together my ar 15 with an Adam arms carbine piston kit .750, with an Allan engineering aem3 suppressor. carbine buffer and carbine spring. when out to the range had gas block set up on suppressor setting. I shot 5.56 ammo and also pmc 223 55 grain ammo. I notice I had heavy recoil and excessive gas (smoke ) coming out of magwell, back of charging handle ,ejection port. and casing coming out of 1 o'clock  position. took it home took apart to clean it and notice also buffer all marked around.. when ahead and purchased a h2 buffer and jp enhanced spring thinking it will fix the issue. went out on the range shot 5 mags of 30 round with 5.56 ammo. not as gassy but ejection of case was still around 1 o'clock..looked at buffer marked all around edge. not sure what it can be.  prior to putting h2 buffer I also replaced buffer spring stopper with an off set pin thinking maybe receiver wasn't drilled properly.. any input to this issue will be greatly appreciated. new to the ar platform and not sure how to fix it.   not sure how to post pics sorry.


lar grizzly upper and lower receiver
bcm 11.5 inch barrel
adam arms carbine piston kit .750
jp enhanced bolt
pri gas buster charging handle
h2 carbine buffer with jp enhanced spring
allan engineering aem3 suppressor
ubr stock with carbine buffer tube
pof roller cam

1st post.. welcome to ARFCOM.

can you tune the gas down any more than that setting?

thank you .  my adam arms piston kit has only 3 setting  1 setting shooting with out suppressor , 2 setting suppressor setting and setting 3 cuts all gas of for single shot

That's an awfully short barrel for a carbine gas system.  The gas port is 7" from the front of the upper.  There's another 1+" of barrel inside the upper, leaving you probably only about 3" of barrel past the port.  That's barely enough for it to function with a DI gas system.  It's possible that this is normal for an 11.5" carbine gas piston gun.  What does Adams say about it?

I have two Adams uppers: one I built with their kit in 5.56mm, and the other is a complete upper in 5.45x39mm.  Both have 16", carbine gas barrels.  They're both great shooters without any nasty habits or issues.

It's really hard to sat whats normal when its a custom build. suppressors add an enormous amount of back pressure. my first 11.5 carbine Adams build, i used a carbine buffer spring, H3 buffer, and the suppressed gas setting. my second i used the more adjustable version of the gas block, and used an H2 buffer and more reduced gas setting.

mebbe step up to a H3 buffer (5.4oz), but these run around $40.

If you want to tinker, on the AA gas plug that goes into the gas block, maybe make the inoperative position (the OFF position), make it operative by drilling a small hole?  I'd do it with a spare gas plug ($40, GP3 from AA).  You'd need carbide bits, I think the steel is hardened, do it in a drill press.  If you shoot a few rounds in the OFF position, you might see a burn imprint on the gas plug marking the spot to drill, just need to drill through to the center bore.  I'd do some research on how small of a drill to start with, 'cuz you can't put the metal back once it's drilled.

When I built my Adams platform, my problem was the inverse. I was too undergassed - even with M193 / M855 full power loads.

You can read my troubleshooting walk-through here:
https://www.ar15.com/forums/ar-15/_ARCHIVED_THREAD____ADAMS_ARMS_mid_tact_elite_won_t_go_boom/126-661003/?page=1#i6668038
https://www.ar15.com/forums/ar-15/_ARCHIVED_THREAD____ADAMS_ARMS_mid_tact_elite_won_t_go_boom/126-661003/?page=1#i6702318

Short version: Then end solution was to bore open the gas hole.

But in your case, with "gas coming out of magwell, back of charging handle ...", this points to be breathtakingly overgassed. These are symptoms expected of a DI gun with a can, not a piston.
If you intent to keep running with a suppressor, before I bore open smaller holes anywhere, I would would probably start with:

- Ask Adams for the dimension of the suppressed setting gas hole. Verify that it's not overspec.  If overspec, send it back and ask for a replacement. If not ...

- Swap your buffer spring for a stiffer one such as a Wolff XP.  No change?

- Try a much heavier buffer. Slash's HeavyBuffer is available from H2/H3 weight all the way up to 10, 11, and 12ozs!

- Finally, if none of these work then it may be time to beging experimenting with trying to tune the gas hole yourself.