Re: Savage Sporter 23B .25/20
I don't have OAL numbers specific to the 25-20. I do have a sheet for those 257 bullets I have or had. PM me your email and I'll send it to you. The Hornady 60 grainer measured 0.52 inches nominal.
There is a formula for figuring out twist rate based on caliber, Greenhill's formula. Google that, you should find it.