45acp flash hole size

[Ohen Cepel]

I have some 45acp brass that has been reloaded many times and the flash hole is large. It is almost as large as the primer pocket. However, the primers still fit as they should. This concerns me, should I discard the brass due to the flash hole size or ignore it and keep going?

Thanks in advance!

 

[BigBore45]

Got a picture?

 

[MutinousDoug]

By your description, I'd say your cases were modified to fire primer only, plastic bullet rounds.

Proper sized flash holes are sized for a purpose. Grossly oversized flash holes are likely to back the primer out and foul up the action.​

 

[ReloaderFred]

My guess is that the brass in question is Winchester, or maybe even Federal. The enlarged flash holes were one of the iterations in the development of the non-toxic primers using DDNP (Diazodinitrophenol) priming compound. The faster brisance of the DDNP priming compound caused the primers to back out faster than with Lead Styphnate priming compound, causing extremely flattened primers and primer flow. The enlarged flash holes were to relieve some of the pressure, which it did.

Those cases are safe to reload, but there's so much .45 acp brass in the world, if it bothers you, then scrap it and move on to other brass.

Hope this helps.

Fred

 

[9mmepiphany]

I just loaded about 600 pieces of Winchester .45ACP brass and found 2 pieces with the enlarged primer holes. I recognized them as being from the Non-Toxic era.

With just two out of 600+, I couldn't see any reason to keep them in the rotation...so I culled them

 

[FROGO207]

As long as the anvil on the primer catches so you can set it when priming you are good to go but as others have said stop using if they bother you. I usually loose my pistol brass before it wears out but some of my 45ACP have a conservative estimate of 50 reloads with no problems.

 

[Ohen Cepel]

Thanks for the advice. I'll cull them to keep things consistent. Really appreciate the insight to the non-toxic primers!

 

[Steve C]

Years ago now I had some of the large primer hole Winchester WinClean .45 ACP cases. I loaded up 10 of these cases and 10 onece fired PMC casess with the same load and ran them over my chrono. The average velocity of each sample was only 5 fps difference thus statistically insignificant but the standard deviation of the large primer hole Winchester brass loads velocities was much smaller than the normal primer hole PMC case loads. After those results I never worried about the primer hole size.

 

[LiveLife]

standard deviation of the large primer hole Winchester brass loads velocities was much smaller than the normal primer hole PMC case loads.

< Note to self - Larger primer holes may lead to smaller SD ... another myth busting thread in the making. >

Thanks!

 

[jmorris]

These are all factory/unmodified Winchester cases



I too had smaller ES with the large hole but you could load a mix of all three mixed and you couldn’t tell a difference between it and “shot separate” groups.

 

[Blue68f100]

Lapua says their 0.058" flash hole gives you a more consistent velocity over the std 0.062" on their 6.5CM SP. All I can say is the smaller hole is a PITA.

You would need to get your pin set gauges out to start sorting, for I bet they are all over the place.