.45ACP - Why different primer sizes?

[23 Blast]

I was batch sizing my 45acp brass, and discovered, while using my primer pocket cleaning tool, that some brass has a smaller primer pockets than others. Specifically, the only brand I've yet seen with the smaller pockets is Blazer Brass.

Any particular reason for this? Is the brass with smaller pockets meant to be used with different powders? I'm a beginning reloader and so don't have experience with this.

[jpm804]

New reloader also and found out about this also when I was prepping brass ....

http://www.shootingtimes.com/ammo/small-vs-large-pistol-primers-45-acp/

[jericho89]

.45 ACP with small primers were made to reduce lead on firing ranges by using primers that use DDNP this is also sometimes referred to as Diazole or Dinol, instead of Lead Styphnate primers commonly used. In an effort to make these special primers work other changes have been made in such things as flash hole diameter and crimp strength. Special powders and other things like neck tension may also be employed but these would be less obvious.

Currently these primers are not widely available and although the major ammunition makers are making ammunition with them they are not selling the components separately. These primers have different characteristics from conventional primers including blast pressure waves and smaller flame footprint which result in less reliable ignition.

[Full Clip]

The use of SP primers in .45 ACP factory ammo was mostly enacted to screw up people new to reloading. Mostly.

[opos]

Seems several of the major ammo manufacturers are making the small primer .45acp...for "plinking and range use"...Federal Champion (Wally world), Federal American Eagle, etc are, among other majors that are seen with the small primer...but not all the time...I understand that when Federal was asked about it they really didn't answer..mumbled something about "economics" and less lead but couldn't answer why it was some here and some there...said the large primer was used in their "premium" lines..I think there are about 6 or 7 companies now using some small primers...just a pain in the rear but they shoot fine..irritating to a reloader.

[23 Blast]

.45 ACP with small primers were made to reduce lead on firing ranges by using primers that use DDNP this is also sometimes referred to as Diazole or Dinol, instead of Lead Styphnate primers commonly used. In an effort to make these special primers work other changes have been made in such things as flash hole diameter and crimp strength. Special powders and other things like neck tension may also be employed but these would be less obvious.

Currently these primers are not widely available and although the major ammunition makers are making ammunition with them they are not selling the components separately. These primers have different characteristics from conventional primers including blast pressure waves and smaller flame footprint which result in less reliable ignition.

So - I can't simply use small pistol primers in the brass with the smaller pockets?

[prod39]

I've heard of others that do use normal SPP in those cases. And, apparently, they work ??
Personally whenever I find those cases, I throw them away,,,,hopefully before they find my de-priming rod and bend it !
( That's what pisses me off the most !! )

['ol shooter]

I had read a post somewhere that it was to make ignition in striker fired pistols more reliable. Another urban myth? I dunno.

[rm1911]

There is a special place in hell reserved for whomever created SPP 45acp.

[M1NM]

Personally whenever I find those cases, I throw them away,,,,hopefully before they find my de-priming rod and bend it !

That shouldn't be a factor both have single flash holes. A berdan primed case can ruin your day.

[Cowboy T]

Everything I've been able to read about this issue points to the lead-free primers. It turns out that Fiocchi does make primers for sale to the reloader. I have used them in .38/357, and they work just fine.

So, why not just use the lead-free compound in large primers? Two reasons.

1.) It seems the brisance (explosiveness) of the lead-free compound can get out of hand when you fill a large primer cup with it, but a small primer cup is fine. So, it's a safety issue.

2.) If you're an ammo manufacturer, any time not spent changing out the SPP machinery for LPP machinery on your assembly line is more time you can spend crankin' out the rounds for sale. That means more money in your pocket. Remember that many of these assembly lines make 9mm, .40 S&W, *and* .45 ACP.

I use and shoot both versions of .45 ACP. I have not been able to observe any difference in any of my loads, nor (apparently) have any firearms out of which I've shot these rounds. Both work equally well. You've just got to remember to examine your cases, which, as reloaders, we ought to be doing anyway.

That said, SAAMI spec says LPP.

[jericho89]

So - I can't simply use small pistol primers in the brass with the smaller pockets?

Well yes and no. Yes you can BUT standard load information is not written for a standard small pistol primer and since there is a difference between the standard and the non lead ones that were factory used you will have different results. This can be an issue with different powders that have different burn rates. You can have reliability issues and different pressure issues. The answer you will get is you need to work up a load for those to be safe.

[Sunday]

Well yes and no. Yes you can BUT standard load information is not written for a standard small pistol primer and since there is a difference between the standard and the non lead ones that were factory used you will have different results. This can be an issue with different powders that have different burn rates. You can have reliability issues and different pressure issues. The answer you will get is you need to work up a load for those to be safe.

I loaded a few hundred small primer 45acp loads using a few grains less powder than my standard load and they worked fine.

[jericho89]

I loaded a few hundred small primer 45acp loads using a few grains less powder than my standard load and they worked fine.

Same here

[23 Blast]

I loaded a few hundred small primer 45acp loads using a few grains less powder than my standard load and they worked fine.

How many grains fewer? I mean, considering a typical charge for most 45acp loads is only a few grains anyway.