Aero Precision 22" upper 6.5 Creedmoor build.............What Buffer / Spring do I use with the Tailhook GenII Brace? I do not have a AGB

308 H2 Carbine Buffer with 308 Carbine Spring?

Thanks,
John

If you can, get an SR25 receiver extension (which is the same rough dimensions as the VLTOR A5 or LMT MWS) and use a standard H2 buffer with a Sprinco blue recoil spring. That combination will give you more flexibility as the large-frame buffers in standard carbine extensions are finicky and hard to tune. KAC designed their receiver extension to allow a large-frame BCG to recoil the proper distance with a standard AR buffer and spring. I have had zero positive experiences with the mini carbine buffers on the large frame and much better results with the longer extension. You'll also have more commonality in parts. An H2 buffer with the Sprinco blue tamed a 16" AR10 platform and I know people using the H3 for hotter loads but I have no firsthand experience there.

You might also have good luck in the AR Variants subforum.
https://www.ar15.com/forums/AR-15/AR-Variants/121/

Thanks TG!