Originally Posted By HKH:
What’s the measurement of the rear of trigger shoe?
https://www.ar15.com/media/mediaFiles/99571/IMG_7372-3669105.jpg

Originally Posted By ELittlefield:
Let's take a step back, and get your 16" midlength upper running first. Try a standard carbine length buffer spring, and an actual H3 buffer with three sliding tungsten weights. Do not use that Odin buffer. If the lever is still dragging a bit, then you have not cut too much off yet. It may be advisable to cut a little bit more, we will see.

Originally Posted By dredeagle:



Odin heavy would not brrt for me.  It is steel bodied and the ratio of sliding weight to total weight is low.  The Odin Light is aluminum bodied and brrts as desired with the improved sliding to total weight ratio.

I've yet to see a report of anyone having success with the odin heavy buffer.

That said, Tromix just runs IME.  Zero adjustments required.  Have you tried it with the standard carbine spring?

Originally Posted By ELittlefield:

Ah. The classic symptom of carrier bounce is a dead trigger with a live round in the chamber. If you're failing to feed a new round, you're either under gassed, or wildly, wildly over gassed. I would guess you're under gassed.

Originally Posted By DutyRanger:


Yes. Tromix with the standard car spring still only gives 2-3 rounds. It was a mix of stopping on an empty chamber with hammer forward or cocked though. Where everything else was mostly empty chamber, hammer forward.

Originally Posted By GunDisaster:
Had to file and dremel quite a bit on the back of the trigger on top and the sides. When you press the hammer down all the way in super mode the catch should move back and forth all the way freely with no resistance.

Originally Posted By DutyRanger:
Atrius gurus, please help. I’m about to lose it with this thing. I have an Atrius Super Selektor installed in an 80% lower, with an ALG QMS trigger. It was built as a pistol from the beginning. It’s currently got a 10.5 PSA 556 pistol upper on it.

I watched the Kurisutofer YouTube video on “How I Tune My Configuration”. I then went through my set up and took just enough off the tail of my trigger to give the lever movement with the hammer fully compressed. I still have just a little bit of drag on the lever with the hammer fully compressed, but nothing I would call binding, just some drag. I then function checked and passed all checks with an upper installed.

Went to the range to test it. Would get a couple rounds then dead trigger. Initial tests were run with Car spring, Car buffer. Also ran it with a KM tactical H3 solid buffer. Same results. No success so figured my buffer or spring was the issue.

Ended up getting Spring Co blue and red springs and Odin Works heavy adjustable buffer. Tried all combos of the Odin works and springs. Still only getting 2-3 rounds. Got 2 more tungsten weights for the Odin Works and filled it up (8-9 oz) and tried again. Same results, 2-3 rounds, dead trigger on an empty chamber. ONCE I managed to get a 7-9 round string (Odin w/ 3 tungsten weights and car spring) and then ran out of ammo on that trip. Next range trip, 2-3 rounds dead trigger on empty chamber. Also made sure I had a new from the package P mag. Same results, 2-3 rds dead trigger on an empty chamber. Changed around the Odin to every combo of weights I could do, same results. After this trip I was about set on an adjustable gas block. I stumbled across the Tromix H3 deadblow buffers on sale so thought it might be worth a try since one of the reviews specifically talked about functioning with PSA 10.5 upper. Got a couple to try, went to the range, same results, 2-3 rounds, mixed dead trigger or hammer cocked, empty chamber. Couple days later decided to try 16” carbine upper. Went to range, same results, 2-3 rds, mixed dead trigger or hammer cocked, empty chamber.

Initially I figured the problem was an overgassed PSA pistol upper. Now after I’ve tried the 16” upper, it seems like that wasn’t the problem since I’m getting the same results. A buddy put an Atrius in his 16” midlength gun and it ran right out of the box. His has what I would’ve called binding with the hammer fully depressed. I have no idea what to think. Have I taken too much off the tail of my trigger? Have I not taken enough off the tail? Can anybody give any incite on this? Is there something else I’m missing?

Originally Posted By bionicmonkey:


OP, i had had the exact configuration you describe, albeit 11.5", Atrius, milspec trigger, 80%, odin heavy buffer, PSA upper, and dead trigger.  the Odin heavy buffer is no good because it has all its mass in the body which doesnt moved back and forth inside, and much less mass moving inside.  a true H3 with the moving tungsten inside a lightweight body is needed - i highly recommend the Gieselle super42.  

now, as to your issue, i dont think the bbl length, or gas is an issue.  back to the basics - im assuming you have a m16 buffer, have you tried the basic function tests and does it drag or fail to fire?  for example in semi your trigger should move freely through its whole range of motion but in FRT with the lever forward does it similarly allow you to move the trigger through its whole range of motion?   I have had some triggers have a slightly too long tail which can make them barely able to release the hammer in FRT and in that case taking a little off the end is needed, and as we know Atrius can require a slight amount off the top sometimes also.  before modifying the trigger tho, is your pocket truly 1.249?

Originally Posted By DutyRanger:
So no new progress on my setup, still no luck with experimenting. But I had a chance to test out another pistol recently. Atrius dropped in and ran like a sewing machine. It was another PSA 10.5. I had a chance to measure the gas port on it and it measured .081. I just pulled mine apart and measured the gas port on my non working setup at .073. In light of the earlier comments saying mine sounded under gassed, and the 081 worked, I think I'm gonna drill mine out that extra 8 thou and see if it works.