45 ACP flash hole size

[Griz44]

I bought a big box of mixed brass from a range and in the process of cleaning, de-priming and checking it I noticed a big difference in the size of the flash hole from one brand to the next. What is the operational difference in the flash hole size? I generally use Winchester primers, and the Winchester cases seem to have the smallest flash hole. Can one expect a performance or other difference between loads with same powder/primer/bullet from one brand to the next based on flash hole size? Just curious.

 

[Mal H]

Unless you're making match grade ammo, the different flash holes shouldn't make much difference.

The large holes are in cases that are factory primed with the relatively new non-toxic primer compounds (non-lead), but they often require small pistol primers.

 

[Steve C]

There is absolutely no difference in load performance. The Win Clean ammo have larger flash holes than the normal brass. I ran a segregated sample of each type over the chrono using the same load of 6.1grs of Unique, Remington 230gr FMJ, WLP primer and the average velocities where statistically identical (851 fps and 852 fps) from the same Colt Gov model.

 

[ReloaderFred]

Just load and shoot, and repeat as necessary.

You may want to watch for the later NT brass, as some of that uses small pistol primers. The early NT brass used large pistol primers, the same as most .45 acp brass.

Over the years, I've run across some .45 brass that used small pistol primers before there were Non-Toxic primers, but they were all either made in Europe or the Balkans.

Hope this helps.

Fred

 

[Rico567]

I have some of the Winchester brass with the large flash holes. Seems to load & shoot just like the other. Winchester's web site actually addresses this issue in the FAQs. They say it's part of their WinClean technology, and shouldn't be affected by reloading.

 

[Griz44]

Cool,
I don't have all the sophisticated tools (yet) to do such detailed testing. Just shooting, I could not tell any difference in the rounds. I appreciate the information. I have been to the range and my favorite plinking place 10 times more frequently since I started reloading. I am beginning to take on the attitude that I need to go shoot so I will have something to reload. It not only saves a lot of money, it is very relaxing and a lot more enjoyable that sitting around staring at the idiot box.

 

[Walkalong]

I stopped segregating them some time back on advise from folks here. I can't tell the difference.

 

[Harley Quinn]

I was not sure why Starline went to the small pistol primer in the 45 ACP/400 CB...
Figured it had to do with newer better technology etc..
The idea of some more brass (smaller hole) had something to due with pressure etc..