CQB is shot at 30 yards and closer, so pin point accuracy and power is not an issue. The main requirement is flawless reliability.
I have about 5,000 primed cases ready to be loaded, but I thought I may as well try some loads and pick the best. I have bulk 55 gr FMJ bullets of unknown make. For powder I want to use a cheap powder that I have a lot of.
In the powder magazine I found a drum of experimental IMR powder they gave me years ago. It is a very fine grain extruded powder about H332 in speed. I also have a drum of ball powder, similar in speed to H335. I have used 24 gr. of this in the past to make CQB ammo.
For the test I loaded 23.5, 24 & 24.5 gr of the ball powder. I wanted to see if a bit more or less powder improved the groups.
For the extruded powder I loaded 22, 23 and 24 gr. All primed with Tula primers and seated 2.240 OAL.
This is 6 different loads. I selected 4 AR-15 rifles that had at least 7X scopes on them. The 4 & 5X scopes are not suitable for load testing. Just by luck all the low power scopes are on NEA rifles, so I did not get a chance to see how they group. Each rifle has a floated barrel and a match trigger. A Norinco, Palmetto State Armoury, Blue Line and Dominion Arms. The Dominion has a new heavy match barrel.
4 rifles and six loads means 24 different groups.
I shot off sandbags at 100 yards. The piece of paper on the bench is a target plot where I note where each group goes, and what ammo it is.
When I get home, I measure each group on the sheet of paper with about 30 groups on it.
With the plot sheet, I can then label each group with the rifle and load.
Groups ran from 1.5" to 2.0". Bigger than I thought they would be. Since they groups were big in all rifles and all loads, I assume the limiting factor is the bullet. I fired a few groups in each rifle with match bullets (68 Hornady and 77 gr Nosler) They group an inch or less.
I have about 5,000 primed cases ready to be loaded, but I thought I may as well try some loads and pick the best. I have bulk 55 gr FMJ bullets of unknown make. For powder I want to use a cheap powder that I have a lot of.
In the powder magazine I found a drum of experimental IMR powder they gave me years ago. It is a very fine grain extruded powder about H332 in speed. I also have a drum of ball powder, similar in speed to H335. I have used 24 gr. of this in the past to make CQB ammo.
For the test I loaded 23.5, 24 & 24.5 gr of the ball powder. I wanted to see if a bit more or less powder improved the groups.
For the extruded powder I loaded 22, 23 and 24 gr. All primed with Tula primers and seated 2.240 OAL.
This is 6 different loads. I selected 4 AR-15 rifles that had at least 7X scopes on them. The 4 & 5X scopes are not suitable for load testing. Just by luck all the low power scopes are on NEA rifles, so I did not get a chance to see how they group. Each rifle has a floated barrel and a match trigger. A Norinco, Palmetto State Armoury, Blue Line and Dominion Arms. The Dominion has a new heavy match barrel.
4 rifles and six loads means 24 different groups.
I shot off sandbags at 100 yards. The piece of paper on the bench is a target plot where I note where each group goes, and what ammo it is.
When I get home, I measure each group on the sheet of paper with about 30 groups on it.
With the plot sheet, I can then label each group with the rifle and load.
Groups ran from 1.5" to 2.0". Bigger than I thought they would be. Since they groups were big in all rifles and all loads, I assume the limiting factor is the bullet. I fired a few groups in each rifle with match bullets (68 Hornady and 77 gr Nosler) They group an inch or less.
