All,

Thank you all for the feedback. My takeaway from this is there are max ‘book’ loads that reach my goals in 24” barrels, a factory GMX that is on goal, and a couple of suggested loads that get there. It seems 3000 fps is reasonable, so I am going to get a 6.5 CM.

As a recap, here are the book loads you all pointed out that nominally meet my 120 gr muzzle velocity goal with 24” barrel:
Alliant - RL16
Hogdon - StaBALL 6.5
Nosler - H4350, RL17, Hunter

So 5 different powders. There were several others very close.

As my username suggests, I like short rifles. Looks like I need to make an exception for this project. For engineering margin, I’m going with a 26” barrel.

Thanks again for your support!

Got it covered with the 22 LR, 30-06, and 12 gauge.
The rest are just for fun.
NRA Life Member
Never let the truth get in the way of a good story.