Jayph;
We used to chase the local coyotes with more enthusiasm than I've been able to muster in the last couple of years, but here is what we learned after trying several firearms for the task including '06's, .308's, .308Normas, .270's and what we finally settled on. This was in pre-range finder days and really I’m not sure we’d have had the time to use one on more than about 1/3 of the called in coyotes anyway.
My hunting finally used a .25-06 in a 26” barreled B78 so we were able to achieve all the velocity that round is known for out of the 75gr Hornady HP he chose.
I settled on a .22-250AI with a 26” No. 4 contour Douglas Premium barrel, 1-14” twist which was screwed into a ’98 action because I had one on the shelf. I eventually settled on 55gr VMax or Ballistic Tips as they seemed to me to buck the wind better than the 50gr.
The 75gr bullets out of the .25-06 were definitely harder on pelts than the 55gr VMax/BT were. In fact we seldom had exits with the .22’s but when they did, it would have meant a lot of sewing to salvage the pelt.
They both would drop a coyote, running or not, in their tracks. The .22-250 had somewhat less flight time at really extended ranges, that is one would watch the coyotes die in the scope with it and the .25-06 was a bit more of a bang, then thump situation.
I would never build another short AI on a Mauser if I didn’t have to. I finally made it feed, but it was not fun. Compared to the 722 actioned .250AI our youngest daughter shoots which feeds flawlessly, there is no comparison. As I said, it was what I had and fit the budget at the time, but I would not recommend it.
Back then (early ‘90’s?) the 1-14” was what we all built our .22-250’s and Swifts with, but now with some of the longer .22 caliber bullets available, I believe I’d run a quicker twist. The faster twist would increase pressure a bit I believe, but the new longer projectiles should also buck the wind better than a 55gr could.
I would also not be inclined to do a No. 4 contour again, as it makes for a rifle that goes about 12lbs and that is 2lbs more than I like to pack these days as I approach 50. I’d likely still do a 26” barrel though, as it does make for a bit more speed and varmint hunting is one place where I’ll still take all the speed I can get.
Hopefully that was some use to you, good luck on your rifle and your coyote hunts. We really did find that it was some of the most fun we had hunting here in the BC mountains- maybe because we didn’t have to pack the animal down the mountain on our backs like other hunting entails?
Regards,
Dwayne