45 Auto brass?

mike992

I got a batch of once fired brass. Winchester,remington, speer ect.... It seems all the manufacturers take a large pistol primer except the speer. It looks like a small pistol primer. Don't know why. Is this unusual? Thanks.

m113103

No, I too got a load of 45 brass and found that when I was cleaning the primer pockets, some of them took a large rifle primer.

RCrosby

Most ACP brass will take the large pistol primer which means that they will also take large rifle primers. Same size, but the cup is thicker and harder on the rifle primers and so the auto hammer often won't impart enough oomph to make things get loud. Even if they do go off, uniformity will be suspect. There are also differences in jacket hardness between brands which is one reason that the appearance of the fired primer is NOT a reliable indication of high pressures or lack of the same.
I have some OLD .357 brass that takes large primers rather than the usual small. Is your small primered brass recent or old, and all of the same manufacturer? Interesting. It may be common, and common knowledge, I just haven't encountered it before.

1911 Gunslinger

quote:Originally posted by mike992
I got a batch of once fired brass. Winchester,remington, speer ect.... It seems all the manufacturers take a large pistol primer except the speer. It looks like a small pistol primer. Don't know why. Is this unusual? Thanks.


The newer ammo with non toxic primers(lead free) use the small primers.

The reason for this is that the lead free primer compound is much more powerful then normal primer mix.

In early production ammo it was found that the new compound produced too much primer pocket pressure with large primers, causing them to back out violently enough to damage the breach face on some makes of guns, there were also problems with gas leaking from the primer pockets and damaging the breech face of guns.

The cure was three fold.
1. Change to small primer size.
2. Enlarge the flash hole in the case to allow quicker pressure drop in the primer pocket.
3. Crimp the primer in place.

some mfg. have tamed down the lead free compound to the point they don't always crimp them now.

XXCross

RCrosby

Large rifle and large pistol primers are NOT the
same size! They are the same diameter but the rifle
primers are taller by about .01 inch. If you try
to use them in a pistol case, they will protrude above
the case head or be deformed by trying to get them
flush. Measure them! There is a reason they make primers
for rifle and primers for pistol. There can also be a
considerable difference in the flame duration and temperature.

If it didn't mater we would just have "primers".

RCrosby

XXC,
I should have been more specific in stating the diameter and not necessarily the height were the same.
That said I've never found that any slight difference in height led to the problems you suggest in seating the rifle primers in a pistol case.