I have the 760 carbine in 30-06. It is the pre-7600 model. 18 1/2" barrel.
I use it for night time hog hunting. The flame ball is huge enough to be seen by the space station! and it is loud! Don't know about velocity decrease, but at 60 yards it knocks the snot out of hogs. Within ten feet it would burn the hair off them to boot.