And was getting 2955fps with the factory federal TNT loads, and 2805 with factory Federal 6.5 MSR load as well.

I'm impressed

I've been into the 6.8 for a few years, and have grown to like the round.

Below results are from pigs ranging in size from 60-120lbs.

100gr Accubonds work well enough. Reliable exits but expansion doesn't seem all that impressive at spc velocities. Have yet to recover one of these bullets. A bit expensive for plinking too, if you can even find them.

90gr Gold Dots are good but did not provide consistent enough exit wounds for me.

120gr SST seem to be a good middle ground between the two above. Better expansion than the AB's and more reliable exits than the GD's. Seems to be a great bullet design and weight for spc cartridge.

Next on my list to try is the Sierra Pro hunter, if I can ever find some.

Your logic on the SSTs matches mine with the 123 gr SST in the 6.5 Grendel. I haven’t used it on a deer, but it works great on hogs, even big ones. I always thought the SSTs were a bit soft for 2900 FPS, but at 2400 FPS they penetrate well. Haven’t seen an exit on a hog yet, but that’s fine with me. No hog has survived.

Just to say it, I’d use it on a deer, but I have more confidence at distance with my 260 and 120 gr Ballistic Tips. But, if and when I run out of them, I probably will go to those 123 gr SSTs and push them at approx 2800 fps. And see what happens…

Give hammer bullets a look. I shoot the 126 HH out of a 6.8 Western and their performance on game is phenomenal. With the 6.8 SPC go as light as you can — 85 or 90 gr.

My 6.8 is a Ruger single-shot so I have no magazine issues. I can seat 130 gr bullets long. My load with a 130 GD & AR-Comp chronos at 2,640 fps. Barrel is 22" long. The 6.8 forum recommend that 130 gr bullets in an AR have the lead tips removed or plastic tips filed flat. A modified magazine is also suggested. The 130 Sierra (PH/GK) & 130 Speer(FB) seem to not perform well out of the 6.8. Note that 130 gr Speer BT is not a HotCore & does not perform identical to the FB version. The BT version seems to expand more rapidly & hold together well in the 6.8. I plan to test this on a deer myself. Just FWIW...