I'm trying to figure out what twist I will need to shoot mostly 69 to 75 grain bullets, preferably monolithics, out of a 25 inch barrel chambered in. 22-250 while hoping for 3000fps.

Does a 1:8 sound right or should I go for the 1:7 if I plan to concentrate on monometals?
Lets say I want to go for coyotes, and use a 50 grain bullets, I suppose I could consider them to about as long as a 70gr lead bullet?

Decisions decisions...

I have a 1x7 and shoot 52gr bullets out and get great accuracy

I would get a 1:8 for bullets 65 thru 80 gr. velocities will be higher than 3000f/s
I think you would need a 1:14 to shoot light bullets.
With 25" barrel you should gain 100 to 150f/s.. just a guess.

I went with a 1/7 to use the 80 G. Sierra in a 22-250 AI (40 deg.)that I built up. Even with the 80G. bullet the M.V. was superior to the 220 Swift + this with a 26" bbl. My answer/reply to the .224 TTH.

Iusually go with a 1x7 it seems to shoot most weights pretty darn good. I used it and lent it to other shooters on cull operation of PG in Africa, whitetail and hog culling in Texas..I don't recall any animal making a track, all instant kills with shoulder, neck and head shots. Interesting and just like PO Ackley said velocity would..Even so I prefer a larger caliber and heavier bullets as those fast bullets just have to fail sooner or later, or maybe Im just an old nickel and dimer and like slow big bullets that leave big blood trails, but that's another issue created by age and a wandering mind!

69-75 mono's will be LONG so I'd think a 7 twist would be in order.

I just finished one (22-250 AI) for my brother with an 8 twist and I'm in the middle of another one for me but they're for 70-80 long BT cup and core bullets and that works out about right. The mono's will require a tighter twist.

Zeke

Whether one is trying to shoot light bullets in a fast twist or long/heavy bullets in a slow twist, a bullets balance and concentricity plays a large part in success.

I believe there is actually a formula that was developed by the navy for calculating the rate of twist for length of bullet to maximize stability.

Berger's website has https://bergerbullets.com/twist-rate-calculator/. Bullet lengths are listed on https://www.jbmballistics.com/...engths/lengths.shtml

I have a 1:8" twist in 220 Swift. I've shot 52gr Sierra Match Kings on the low end and tried a few of the 70gr Barnes TSX that a friend gave me to try out. My gun shot them just fine. My prefered bullets are the 77gr Sierra match Kings or the 75gr Amax. The 69gr Match Kings also work well from it.