I am going to re-barrel a Kimber Montana to 22-250 AI and going to use a Lilja modified 84M contour. I want to try the 88 grain ELD-M but if it doesn't preform on deer and antelopeI will probably drop down to a 75 Swift Scorocco or 75 Hornady HP's for hunting.
I live at 3000 ft elevation and all the hunting I do with this rifle will be at this elevation.
Question 1-7 or 1-8 twist
3 groove or 4.
I already have die and brass so the Creed argument doesn't much matter.
Thanks
I have and have had many 22-250AI's over the years (I have my own reamer)..........that said
A 22-250AI with 1-7"twist 3 groove is a Fhuqking disaster waiting to happen. more bullets will blow-up than make it to target, if going this route absolutely go with a 5R or 5C or 6groove barrel. the 3 groove barrels work well with 223 velocities but not with 22-250 velocities BTDT
Depends on bullet weight... I tried shooting 40's out of my 7 twist 223AI with a 5r barrel, and it was blowing up bullets mid-air. You'd see a puff of smoke about 50 yds out. I posted that here prior, and the experts called me a liar....
I'd build an 8 twist, but I also shoot at 7000'. I believe Sierra claims you need a 6.5 twist for their 90's, but I am guessing they are assuming a 223 at sea level. Velocity and elevation gives you more latitude with regards to twist rates...
