The key facter in the bullet is what material it is made of , with a jacketed lead bullet I would guess about 240 to 260 would be a good area, you might check out
http://www.prbullet.com/
If you can check the specks of the bullet for length. You might check with Lane to he is very sharp on an awful lot of this stuff, you also will have to get the right fit that takes the right sabot as well as the right bullet. Lee