I've had an AA tac elite midlength upper on a RRA lower with a standard carbine buffer (which is what AA says it's designed for) for many years and thousands of rounds.  It was just a general purpose rifle for fun on the range and always worked, so I never did much in the way of tweaking.  Now I'm getting into competing with it and have a renewed interest in optimizing performance and reducing/smoothing recoil.

As it stands, the ejection pattern suggests it's over-gassed - spent brass lands at 1:30-2 o'clock.  It has a 2-position gas block, but won't fully cycle on the suppressed setting which isn't surprising.  So now I'm looking at spring/buffer combos.  I just put a JP tuned/polished spring in it since it was on sale at a place I was ordering some other stuff from and I know they make good products, but it's only listed as like 7% increased rate so it didn't really affect the recoil or ejection.

So... what buffer/spring setup would you guys recommend for a 16" midlength piston upper?  I've done a ton of reading on the options but of course the vast majority are for standard DI setups.  I figured that should still be close enough but I see several companies recommending 1 step heavier for piston guns - which also isn't 100% helpful since there are a variety of piston designs.

Geissele Super 42?
Tubb flat wire?
Strike Industries flat wire?
Springco blue?

Spikes T2?
H?
H2?

Armaspec Stealth captured spring?

At this point I'm not really wanting to spend the $130+ on the JP SCS or change to an A5 system.

Thanks!

I just do the last-round bolt-hold-open test to find the heaviest buffer that still gives me LRBHO with the ammo I intend to use.  it's gonna vary with every upper configuration.

I'll get some weights and start with that, but it only answers the buffer weight question and doesn't really help me with spring rate.  Or should I just do all the 'tuning' via buffer weight and just use any old spring?

I use the standard chrome-silicon M4 carbine buffer spring in all my lowers.   and tune using the buffer weight, and if I'm not in the ball park with that, then the barrel gas port gets addressed.  But that's just me, JMHO.  All of my AA piston uppers use the std M4 carbine buffer spring, I have a few.  I know a lot of other folks use all the flavors of different springs that are avail for the AR-15 platform.  It's America.

I'll start with buffers and see how it goes.  Again, the rifle works fine, I'm just trying to optimize its performance, improve the ejection pattern, and reduce recoil a bit for competition purposes.  I have 3 weights on order so I can change my two carbine buffers to an H1 and H2 and swap them out quickly and easily.

I am running a BFSIII binary trigger and had to go with a Sprinco red buffer spring and heavier buffer (Added tungsten weights) but that was to address tuning for the BFSIII. Ejection pattern is normal with this combo. My upper is an Adams Arms 16" mid as well. I agree with your approach regarding the buffer to start with.

Well it still runs just fine with an H1 and H2 buffer and JP enhanced spring.  Ejection is at 2-3 o'clock.  Next time out I guess I'll try H3.

I'm running standard carbine weight and spring on my setup

That's what I ran for the first several years of its life.  It worked fine so never really thought much of it.  It's only recently that I've been more interested in competition that I'm wanting to optimize everything for flat shooting and reduced recoil.  Wishing I had the new P series adjustable gas block.