45 ACP with Magnum Primers...?!?

[AJMD429]

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I wouldn't have known you could do this - https://www.handloadermagazine.com/bullets-brass-24

I thought somewhere I read that using Magnum Primers instead of regular ones might cause pressure spikes. Maybe that was in bottleneck cases or longer barrels.

[Scott Tschirhart]

I bought several flats of Tula large pistol primers during the first primer scare. I loaded most of them in .45 ACP and .44 Special cases. Never saw any reason to change.

[Walt]

You're right about that. As an example, Elmer Keith wrote that his .44 mag loads of 22 gr of 2400 should only be used with standard primers because magnum primers would create excessive pressure. Besides, it is said that pressures tend to be more uniform with standard or even match primers than magnums. In handguns I use magnum primers only with 296/H110 loads because I have seen the results of using standard primers; stuck bullets, unburned powder spilled everywhere.

[JimT]

You might want to check this out ... pressure and velocity tests by Super Vel using Small Pistol Primers ... Small Pistol Magnum primers and Small Rifle primers in 9mm ...

https://www.youtube.com/watch?v=NGVRGsoOr6k

[stretch]

That was a very informative video, Jim T.

Thanks for sharing!

45ACP is a relatively low pressure cartridge, so unless I was loading something
that was at or over the published pressure limit for this cartridge, I'd use what
I had.

That thinking might change a little bit for a high pressure cartridge such as a
357 Magnum; or a powerful rifle cartridge.

My understanding is that the magnum primers are used to ignite some of the more
stubborn powders at higher pressures. The primer itself doesn't increase pressure;
it's only used to ensure complete and consistent combustion of some powders in some
circumstances. I'd guess that a magnum primer could contribute to a faster initial burn
rate for some powders, thus raising pressure. There are some cautions out there for
using magnum primers with modern 2400, for instance.

Cool discussion, and it's good to see some real lab data supporting a conclusion.

-Stretch

[Walt]

It is an interesting video but it is also fascinating to note the variation of velocities within the groups of each primer type. These numbers are from his chronograph.

Standard deviation of small pistol primers is 3.98

Standard deviation of small pistol magnum primers is 12.86

Standard deviation of small rifle primers is 21.95

Whether that is significant is certainly debatable but it suggests that accuracy potential may be better with standard primers.

[JimT]

Whether that is significant is certainly questionable but it suggests that accuracy potential may be better with standard primers.

That is quite likely it would seem. However I found it quite interesting that if you are in a "use what you have" situation any of them will work.

[stretch]

Good point, Walt!
I wasn't really paying attention to that, more the pressure differences.

So, as is usual, one has to do one's homework for really accurate target loads!

-Stretch

[Bronco]

I have been using Winchester LP for ages that are for both standard and magnum loads! Wonder where that falls into this discussion ?

[Walt]

Bronco, I've always cringed a little reading the Winchester primer application for both standard and magnum loads. Doesn't make sense to me. I only use Winchester primers that say they're for standard loads.

Jim, I agree with you that especially in handguns, shooter inaccuracy will always represent greater dispersion of shots than differences in standard deviation.

[Griff]

I have also been using Winchester primers since the late 1980s (found the Winchesters seated easier than CCI on my Dillon... (I have no clue why so don't ask). I bought them by the 1K brick until about 1993/4 when I bought my first 5K case and they were only available in the Std/Mag version At the time Winchester said no difference in loading, so that's what I went with. Nor have I found any difference. So, nearly every package I've seen in the last 30 years has been marked for Standard or Magnum loads. I'm on my 3rd case... I neither load near max, nor for any magnum loads, the sole exception being some hog/pig loads for the Rossi 1892 in 45 Colt with a Hornady 240HP designed for magnum velocities. Nearly every pistol primer I've ever used either went into a 45ACP, 45 Colt or more recently in the C45S. Although I have loaded several hundred 44-40s over the last couple of years. The vast majority of those have been for competition in cowboy action, with bullets in the 160 gr to 230 gr, with the majority being a 200 RFN, handgun velocities from ~650 to 825ish. The 1911 nearly always runs with a 200 RFN @ that 800+ fps. I can't remember in the pistol when I've run anything but the Std/Mag Winchester primer, certainly not since I got a chronograph. So I can't provide any real world comparison.

[JimT]

I have also been using Winchester primers since the late 1980s (found the Winchesters seated easier than CCI on my Dillon... (I have no clue why so don't ask).

I use an old RCBS hand-priming tool and have since the 1980's. I found a long time ago that CCI and Winchester feed primers into the seating stem easier than Federal primers. I have no clue why.

[Walt]

I always assumed (without proof) that CCI primers from 30+ years ago were hard to seat because they were a bit out of round. I had trouble with CCI primers, both small and large pistol due to primer punctures. An example with small pistol primers was a .357 load made up of 13.8 gr of 2400 behind a 158 gr cast bullet that I loaded in1992. An example with CCI large pistol primers was a .41 mag load using 12.3 gr of Blue Dot behind 215 gr bullets, another with the same bullet and 7.6 gr of Green Dot. Despite the loads being reasonable, the punctures approached 10%. Since those days I have had no more trouble with CCI primers and in fact generally prefer them to others.

[Sixgun]

I have a simple formula……any rifle powder slower than 4350 gets magnum primers and for handguns any powder slower than 2400 gets magnum primers.

Keep in mind that magnum primers are made for full high pressure loads to get top performance. I use small rifle in the 357 Maximum. I’ve loaded for the 378 Weatherby magnum and used 4350 with standard rifle primers. Big deal, the 270 grain bullet goes 2700 instead of 2800…or whatever the numbers are…….

In the Maximum I needed full pressure loads to knock over the 80 pound rams at 200 meters with 180 Hornady and standard rifle primers did fine with 296.

I see no need for extreme top velocities in any cartridge (except the Max.) therefore, out of my 40K + inventory of primers, only a couple of hundred are magnums and they are getting old…..

Not sure about today’s CCI primers but when I used them I’d get occasional misfires if my revolver had a lighter than standard mainspring. I suspected their cups are thicker or not properly annealed.

98% of my primer inventory is Federal.

[Walt]

I have a similar number of primers. I think Federal makes some excellent primers...some people complain that their boxes take up too much space but I've got plenty of room. Most of my primers are CCI and Remington with Winchester and Federal being a smaller proportion. I'm sure happy that Cabelas has had primers available the past few months. I'm back up to my earlier levels.

[Bill in Oregon]

Useful video, Jim. I have been wondering about which primer to use with the .30 Super Carry as some sources say small rifle and others simply say small pistol.

[Walt]

This primer test was shown on a cast bullet forum. The tester obviously put a lot of effort into coming up with these data. Interesting article.

https://www.castingstuff.com/primer_tes ... erence.htm

[Scott Tschirhart]

I’ve used small rifle primers in .357 Magnum loads for more than 30 years. I don’t think I’ll ever change.