Well, you’ll certainly need to use an energetic powder. And to obtain that kind of velocity with that much weight would require a very wide meplat. I think I’m in the ball park using a weighed 33 grns of 3F Olde Eynsford. I still need to further work on the bullet, but so far it looks like it will weigh close to 230 grns.
What I’d suggest is use an adjustable measure that you can work in 2.5 grn increments and see where your best groups are with a ball. I’ve fired nearly a dozen bullets in my Ruger and a couple in my NMA and I’ve found that the projectile doesn’t seem to effect the powder charge. So use a ball and measure how much excess chamber space you have. Subtract 1/16” each for the amount of space needed to keep gas cutting from happening, one for possible powder volume variance, and one more for punched cardboard over powder cards if you want. That should maximize your gun’s capabilities. 25 grns of an energetic 3F with a bullet should get you low 300 ft/lb range or .44 Spl performance levels, which, to me, is the minimal I feel is humane for hunting.
Your shorter barrel should do just fine as long as it’s not a primary. I’ll see if I can dig up the info from another forum, but someone chronographed theirs and was blown away that a 200 grn Lee bullet was giving upper end .45 ACP performance.
