Buffer recommendation on 10.5 build

[biodsl]

I just purchased a new, old stock 10.5" Alexander Arms barrel. These were sold in the 2011-2012 time frame as part of the Tactical series of rifles. Chromed-lined, fixed triangle sight post, carbine LGS, old school. Exactly what steel case was made for. I purchased stripped upper and AA branded lower to build a kind of tribute to AA and the Grendel cartridge. "AK ballistics in a 10.5" barrel" is how Bill A. described it.

I'm looking for advice on buffer weight. What's the best guess?

EDIT: This is pretty embarrassing. There are a TON of threads on buffers and springs. I've also emailed AA asking for their advice. Still some difference of opinion on whether a H3 is needed if unsurpressed.