90gr TNT was one of the original Alexander Arms factory loads, but was discontinued for this reason.
You really have to push it to get the gas system to run in many of the common gas system configurations on the market.
It runs perfectly in my 12 suppressed, but unsuppressed, I had 2 FTFeed and Failure to Lock back on last round. Thats CLGS even, but not a lot of dwell time with 12 unsuppressed.
That was all with Federal factory 90gr TNT, which is a screaming little round at the muzzle.
Im averaging 2698fps with it at the muzzle from the 12 suppressed.
16 CLGS will run it fine with most port sizes .076 and larger, but then you often get excessive cyclic rate with 120gr and higher.
31.7gr of H335 is one of the best-performing max loads in all of the industry tested and published data under 90gr TNT.
Are you backed-up on that bullet? If 95gr V-MAXs were available, I would point you there. They pressure-up better and dont "punt out" as fast.
You could try a low-mass carrier to see if that helps.
Another thing would be to seal your gas system at the block and the gas tube to make sure there isnt any leakage.
Also, check your bolt-to-carrier gas seal by seeing if there is any soot in the fire control group pocket.
You really have to push it to get the gas system to run in many of the common gas system configurations on the market.
It runs perfectly in my 12 suppressed, but unsuppressed, I had 2 FTFeed and Failure to Lock back on last round. Thats CLGS even, but not a lot of dwell time with 12 unsuppressed.
That was all with Federal factory 90gr TNT, which is a screaming little round at the muzzle.
Im averaging 2698fps with it at the muzzle from the 12 suppressed.
16 CLGS will run it fine with most port sizes .076 and larger, but then you often get excessive cyclic rate with 120gr and higher.
31.7gr of H335 is one of the best-performing max loads in all of the industry tested and published data under 90gr TNT.
Are you backed-up on that bullet? If 95gr V-MAXs were available, I would point you there. They pressure-up better and dont "punt out" as fast.
You could try a low-mass carrier to see if that helps.
Another thing would be to seal your gas system at the block and the gas tube to make sure there isnt any leakage.
Also, check your bolt-to-carrier gas seal by seeing if there is any soot in the fire control group pocket.
NRA Basic, Pistol, Rifle, Shotgun, RSO
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
www.AR15buildbox.com
CCW, CQM, DM, Long Range Rifle Instructor
6.5 Grendel Reloading Handbooks & chamber brushes can be found here:
www.AR15buildbox.com