6.8 question

[mr.trooper]

If factory ammo velocities are around 2,400 fps from a 16" barrel, What velocities could be achieved with hand loads from a 26" barrel, tryin to stay under maximum?

 

[moosehunt]

That question can't be answered simply based on adding 10" of barrel. Going the other way, and assuming that maximum velocity hasn't already been attained, it is a general rule of thumb that for every inch removed from a barrel, 50 to 100 fps are lost. Taking a mean of 75 fps and adding, i.e. 750 fps with the additional 10", one comes to 3150 fps. I seriously doubt that it will happen because your small case simply doesn't hold enough powder to still be accelerating the bullet for 26" of barrel. I'd predict that somewhere between 16" and 26", one will find maximum usable barrel length, hence, maximum velocity attainable with the cartridge, and it will be less than 3150 fps, probably by quite a bit. Have fun!