Re: Hornady 68gr BTHP
I had mine running around 2560fps (little slow) but they were really accurate. I have since bumped them up to around 2800fps and found another accuracy node there.
As far as hunting, my recent experience differs from the previous poster. This year, my kid shot a 200lb pig at 100y. Kid punched him dead on in the shoulder and the thing was DRT about 30 feet away.
Kid also shot a doe (dressed at around 100#) from 155y. Punched her slightly behind the shoulder. She ran about 30 yards and was dead. Field dress showed her L lung was literally vaporized and most of heart as well.
Neither bullet left the animal put penetrated deep.
As to the OP, I have found them to stabilize with no problems and you will likely find threads confirming this. Same setup as you with both barrel length and twist.
LD