How much slower speeds, if any, would you expect to get from a 1-9 twist 22-250 as opposed to a 1-14 twist 22-250 with say a 55 - 60 grain pill?

Kirby Allen a well known gunsmith answered that question for someone with info from Dan Lilja's of lilja barrels website.

There is only the slightest amount of velocity loss with a fast twist barrel.
Building a rifle thinking you'll get big velocity gains with a slower twist isn't worth it.

In my expierence 1-14's won't shoot 55-60gr bullets as well as 52-53gr bullets.
A 1-9 will shoot 55-60 and might be getting iffy on 75-80's.
Go 1-9 or 1-8

Thanks, didn't know if the resistance of the faster twist would affect velocity much. I already have the 1-9 barrel. Just have to get the gunsmithing done. Bought one of Montana Rifleman sale barrels for my Win 70 SA which I picked up in a pawn shop for $275 a few years ago. I has a 19" barrel but can't find anything it will shoot anywhere close to MOA.

Yuup make a tomato plant stake out of that old 19" barrel ,good snag on the $275 win. short action.

Don't think its even long enough for my tomatoes.