buck460XVR
New member
So, add 400 fps due to increase barrel length and I should get around 1900 -1977 fps........looks like the starting load will be a bit too much since the bullet is rated up to 1800 fps, so my starting load will be 14.5 gr and I'll chrono it.
The 1900-1977 are muzzle velocities. I doubt if any deer is going to let you walk up and let you put the muzzle to their chest. 40 yards downrange and you will have lost 150fps. Puts you right in the "window" of the bullet's parameters. I also doubt of you will get a full 400FPS more from a 20" barrel over a 10" test barrel. Ballistics by the Inch, shows less than 100 fps increase from a 10" to an 18" using a 158gr pill in a .357. Even iffin you double that, you're still under 1800fps. Iffin you're a tad over 1800 fps,even 1900 fps, I highly doubt if you will have catastrophic terminal performance failure. Besides, iffin you're gonna slow the bullet down that much, there are better powders to do it than downloading Lil' Gun that much. Use the XTP-FPs and your Lil Gun(at published levels, 16-18) and quit ftrettin' so much.