The "best" way to soften the recoil impulse of almost any AR is to first fine tune the gas system by using an adjustable block, followed by a combination of suitable muzzle brake, then the typical "heavy" buffers, carrier weights, etc., if necessary at that point...particularly useful when shooting suppressed ARs.
Shooting hotter handloads from your AR, I would bet you money that you are WAY overgassed. Adding more buffer weight may help to curb at least some of the effects of the problem (YMMV)...but it does NOTHING to treat the root CAUSE of the problem. On the other hand, an adjustable gas block will allow you to fine tune the amount of gas flow required for your rifle to achieve optimum performance/cycling even with hot loads. By doing so, you decrease the cyclic rate, lessen the force/impact of the action cycling, reduce wear/tear on components, etc., etc. There are a variety of different manufacturers of adjustable gas blocks in various sizes, configurations, adjustment types, etc., but that's where I'd start my quest to settle your rifle down with hotter reloads. Try running a search on adjustable blocks here on the Hide (and BARFCOM, etc.) and you should get more than enough info on different setups to keep you busy reading for a few hours (or more).
As for "quieting" the SPPPPPRRRIIIINNNGGGG noise...again, there are a variety of ways to attempt it. There are the silly Twangbuster inserts, the JP Silent Capture spring setups, Heavy and XH buffers (like those from Slash/HeavyBuffers.com which are my personal preference for heavy buffers), XP buffer springs, etc. There are tons of threads out there on these items, but again...fix the root problem FIRST, then go from there on the rest.
