With the 14" twist that was in a lot of old .25-20 rifles, and relines for same, an 85 gr bullet is pretty much on the margin for stability, at least as the velocities the old rifles were run at.  I've seen oval holes at 100 and 200 yards with the 25720 at 85 gr but never saw one tumble, so they are certainly shootable.

The .25-20 SS was originally designed for a 77-gr bullet  The ammunition companies came up with an 85-gr loading for reasons nobody could figure.  A.C. Gould, editor of Shooting and Fishing, famously commented, "Thus a superior hunting cartridge was turned into an indifferent target cartridge."

If my memory is correct Stevens .25 center fire barrels were 1 in 13 twist.
I also have a Redman liner in 25-20 SS that was done 15 or 20 years ago.
I am shooting a Barnett bullet that is 89g and .835" long.  I shot it Sat. and 
the bullet does not tip at 200 yds but the amount of 4227 powder that I use
would be unsafe in 44 action.  Your action may prevent you from achieving
full stabilization with that bullet.
Other people can give you a hint of how much powder you can use in your
action and be safe, but not I.