That looks like a fun project.
Should push a 55gr to 3900ish, no?
I think thats a realistic estimate.
Won't know for sure untill I get some ladders shot and see where the pressure is.
Good evening to you sir, I hope the day behaved for you and all who matter to you are well.
Thanks for the thread and the build specs, it looks like an interesting project for sure.
Just looking at the cases, that is a .22-250AI that I've got and a .243 case, I can't see why 3900 with a 55gr would be a problem to hit or exceed.
Years and years ago I built a long range coyote bomber with a 1:14 twist in .22-250 because that's what we did then. It's a 26" Douglas Premium Air Gauged No 4 contour so not really a lightweight rifle, but it'll push 55gr VMax or Ballistic Tips to 3850 with either IMR or H 4895.
Photo of ancient boomer coyote medicine.
When our youngest daughter started hunting, she got a whitetail doe draw and we were hunting the hayfields of the fellow we bought horse hay from, so packing the gun wasn't an issue. I went as far as loading up some 55gr Hornady Spires in it and also bought some 60gr Partitions, but she killed her young doe with her .250AI without needing help from the Old Man, so that was that for testing it out on deer.
As GWP said, it's absolute death on dogs. Crazy really compared to almost anything else we tried.
I want to say that Eileen Clarke has been using a .22-250 on some smaller big game the last few years too and the reports have been all great, so yours should be just a bit better than great, you know?
Thanks and good luck on your hunts with it.