I'm no gunfitter, Steve, but I agree with Jim that you would most likely be better off with less than 15.25" l.o.p. I can shoot guns reasonably well that vary from 14.5" to 15.5", the longer ones for premounting. Just my observations, no more, from 50 years of shotgunning.

Shoot as much as you can, in lieu of a gunfitting, and you will eventually work it out to your satisfaction. The above are just rough guidelines.

All my best, Stan

May God bless America and those who defend her.