In the past, I noticed that 9mm can be finicky with brass.
So I loaded 2 batches. One batch with BLAZER brass and one batch with WIN brass.
I wanted to see if it would make much difference.
Here are the specs on the test loads:
Speer 124 gr GDHP (pulled)
5.5 gr. CFE pistol
Fed100 primers
OAL= 1.12"
Taper= 0.375
Chronograph results 11/7/2021:
Test gun was a G17 with an aftermarket bbl.(cut rifling)
BLAZER cases= av. 1154 fps SD=8
WIN cases= av. 1164 fps SD=11
(note: factory ammo clocked 1151 so this is pretty darn close)
Accuracy impressions:
Testing was from the bench at 25 yds.
I think the BLAZER cases produced tighter groups, but I got fliers.
I fired 2 each 5shot strings and got 2 fliers. The rest of the 8 rounds grouped about 2-1/2 inches.
see the pic:

The group with the WIN brass was not quite as good but not horrible.
Point of impact was approximately the same.