I am cutting a 29in. millitary barrel at the first step behind the muzzle.This will drop the length to 23in. and I am wondering how much volocity I'm giving up. With the 29in. barrel I was getting 2420fps with 250gr. woodleighs,with the bullet seated to the base of the neck.The barrel has a very deep throat which allows this.
The rifle will be used for bear protection around camp and see alot of time in my boat when I'm fishing. The 29in. barrel was just to long for a boat gun.
If there's anyone who can give me a ballpark volocity loss i'd greatly appreciate it.

Quickload says that 50.47 gr H414 will push a 250 WL 2420 fps from a 29" 8mm barrel at 47,894 psi.

If that barrel is reduced to 24", the velocity goes down to 2325 fps.

Thanks for the fast reply. I thought I'd lose 200fps by doing this so I'm glad to here its not going to be so much of a loss.
A 250gr woodleigh at 2300fps should take care of buisiness.

The rule of thumb for barrel length and velocity is a 50fps. loss for each 1 inch of barrel. That's not
absolute, but it's pretty darn close.

Cal - Montreal

Was up to Safari Outfitters in Milbrook NY today and there was an M70 Target, serial no. from 1949, in 8x57 with 29" barrel. Did not bother to look at the price tag.