The 9mm XTP Project
Part 1- Defining the Goal
A friend requested that I reload some 9mm ammo for him.
It was supposed to SIMULATE his choice of home defense ammo. The logic being that one should practice defensive shooting skills with equipment equal to, or very similar to what is actually used. Ideally the ammo would have the same shape, size, recoil, and point of impact as the original factory ammo.
In this case it is the Hornady 124 grain XTP Hollow Point. (A truncated cone-shape.)
The factory spec for that ammo is 1110 fps from a 4" test barrel.
My sample measurements taken from supplied ammo was as follows:
LOA=1.060” with a standard deviation of 0.006”
Case mouth diameter= 0.374”
Bullet wt= 123.8 gr. not sealed with asphalt
Powder= 5.5 gr. of unknown flake-style propellant. (very uniform flakes)
Chronograph test from my SW compact 9mm-3.5 in stock bbl.
1065, 1046, 1046, 1037, 1032 fps
Av= 1045
Sd=12
It was expected that my local test speeds would be lower than factory spec because my gun has a shorter bbl and is a stock item. The longer 4” test bbl will shoot faster and since it is probably cut to tighter tolerance, it will shoot even faster than a typical 4’ gun bbl.
EG. A 5’ colt 45 acp bbl will shoot slower than a 5” match grade colt 45 acp bbl.
So now that I have defined the goal, let’s see if we can come up with something that approximates the original factory load. (124 gr JHP-TC at 1045fps from my pistol)
To be continued....