Put your calipers away. The 125 XTP is a revolver bullet with a cannelure. Crimp it in the cannelure - done.
Have you put the Buffalo Bore 125 XTP's in
your gun and chronographed them? If not, you're chasing a ghost.
Also, speaking for
my 4" bbl 686, the velocity champ powder with 125's is Power Pistol. H110 is too slow for the short barrel - it just delivers a bunch of flash and recoil. Shooting H110-loaded ammo through short-barreled guns is silly. The 4-foot flame bloom and tremendous recoil gives quite a show at the range; but it's otherwise silly. Works great in my 8-3/8" bbl 686 though
And . . .
I have no desire to emulate Bullfalo Bore's ammo. Not knocking their products; I just personally find it pointless. And notice I said "emulate," not "duplicate." They are probably using a bulk non-canister-grade propellant. So not only is it pointless, it's hopeless. I recommend building
your ammo, and let them build their ammo.
Point to ponder . . .
How fast do you really want your 125's to go? Why? Do you know the 125 XTP's terminal ballistic characteristics at increasing velocities? I'd venture to say that their optimum performance is probably no more than 1400 f/s. After that, their expansion probably becomes too violent for proper terminal performance. And they're likely designed to reach optimum performance starting at about 1200 f/s or so.
The 357 Mag 125 XTP defense loading I settled on (not the max tested) is 9.6gns of Power Pistol (in compliance with Speer #14). Delivers 1371 f/s through my 4"; and 1307 f/s through my 3" (also a 686). That's plenty of performance
for me.
