One of the requirements of doing gun tests for the NRA publications is that they have a standard requiring testing ammo of three different projectile weights from three different manufacturers, preferably. That's five 5-shot groups fired for accuracy and a ten shot chronograph string. The mathematically-inclined among you will work out that this means I soon wind up with a lot of 50-round boxes of ammunition with only fifteen rounds left in them.
Today I disposed of some of those odd lots of 9x19mm by firing them through the Gen4 Glock 19. Fifteen rounds of Armscor 147gr FMJ in the Magpul 15-round mag, fifteen Sellier & Bellot in a factory mag, and thirteen Federal 9BPLE 115gr +P+ JHP in another factory magazine. (I'd blown two extra checking for POA/POI variance in the magazine test; the subsonic ammo shot so close to the sights that I wanted to make sure I knew where the 1250fps+ JHPs were going to be landing before I attempted shooting for groups.)
The one hundred round box of 115gr American Eagle FMJ went fifty rounds in the ETS magazines and the balance in some factory Glock mags.
Between POI differences among the three different loadings plus outrunning my headlights a bit in the speed department, that scattering of rounds in the head area of the B21E target is bigger than I'd like at ten yards. I need to put some real sights on this gun.
There were no malfunctions of any type to report.
That makes 643 rounds through the Gen4 19 since it was cleaned or
lubricated with one failure-to-fire (#205). 1,357 rounds to go.
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