03-09-2023, 07:15 PM
I have built multiple 20 6.5 Grendels using standard carbine RETs, as well as A5 and rifle RETs.
I have also tested 2.9oz, H, H2, ST-T2, JP SCS, MGI RRB, 5.2oz Rifle, and other buffers Im sure Im forgetting now.
I have also tested different spring weights.
20 Lilja, Satern, and Bartlein barrels with .094 gas ports ran the smoothest with A5/Rifle spring/A5 buffer or Rifle buffer/Rifle spring/Rifle RET set-ups.
Next smoothest was MGI RRB and JP SCS in carbine RETs.
Next was H2 and ST-T2 buffers with stiffer springs (Springco Red works for this).
Standard carbine buffers allowed a bit faster cyclic rate and felt a little more punchy in the reciprocating parts stroke.
This is all off the top of my head, but all of them did function and lock back on empty mag after last round at ~60 degrees F ambient temp.
For your purposes, I would recommend an H buffer with a Springco Red.
A lot of this will depend on how efficient your gas system is though. Avoid the gimmick coatings and weird carriers if possible, and use a Mil-Std carrier with hard chome lining inside the bolt bore and carrier key. If youre using a LH carrier, your options will be limited though.
There are a lot of non-spec carriers on the market nowadays.
I have also tested 2.9oz, H, H2, ST-T2, JP SCS, MGI RRB, 5.2oz Rifle, and other buffers Im sure Im forgetting now.
I have also tested different spring weights.
20 Lilja, Satern, and Bartlein barrels with .094 gas ports ran the smoothest with A5/Rifle spring/A5 buffer or Rifle buffer/Rifle spring/Rifle RET set-ups.
Next smoothest was MGI RRB and JP SCS in carbine RETs.
Next was H2 and ST-T2 buffers with stiffer springs (Springco Red works for this).
Standard carbine buffers allowed a bit faster cyclic rate and felt a little more punchy in the reciprocating parts stroke.
This is all off the top of my head, but all of them did function and lock back on empty mag after last round at ~60 degrees F ambient temp.
For your purposes, I would recommend an H buffer with a Springco Red.
A lot of this will depend on how efficient your gas system is though. Avoid the gimmick coatings and weird carriers if possible, and use a Mil-Std carrier with hard chome lining inside the bolt bore and carrier key. If youre using a LH carrier, your options will be limited though.
There are a lot of non-spec carriers on the market nowadays.
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