I don' have a .25-45 Sharps, but I did build a custom .25-223 AR15 about 4 years ago. Pretty much same thing, but mine has the case trimmed 2mm shorter. Allows the use of heavier bullets with the same OAL.
I built it for my youngest daughter to deer hunt with. She came out twice, didn't kill anything and gave up on hunting. I shot a hog with it this past march.
"If your plan is for one year, plant rice.
If your plan is for ten years, plant trees.
If your plan is for one hundred years, educate children."