Substituting small rifle primers in the 9mm.

2020 has been the perfect storm for panic buying of firearms and ammunition. Over the years I have seen the panic set in, beginning with the assault weapons ban and Brady law, to the Obama election, and of course Sandy Hook. I’m sure there are a few mini waves of panic moments I have forgotten about. 2020 however has taken the crown in the panic competition, so far.

This year we had a triple whammy. The pandemic gave some a sense of insecurity and possibly the fear of zombies. The Democrats decided to let their cities become insurrection zones. Then the presidential election brought up the rear.

.All panic buying seems to follow a certain pattern.“I don’t have a gun, I should buy one. And some ammo.”“People are buying guns and ammo, I should buy more.”“I’m having a problem finding ammo, I should start reloading.”“Hay, does anyone know where I can get some primers?”If it’s not primers then it’s powder or bullets or brass but it’s something.

With this in mind, a question that often comes up about using rifle primers in pistols. Before we go any further it should be pointed out that large rifle and large pistol are not dimensionally the same and can not be switched between the two.

Small rifle and small pistol primers on the other hand are the same dimensional size and seating small rifle primers into a small pistol case works just fine. The question is, should you and what can you expect to happen if you do.

I have used small rifle primers in the 9mm in the past when small pistols were not available. The only time I ever had an issue was when using Wolf AR rifle primers. They were a little hard and I had problems getting them to ignite. If I remember correctly I was getting about a 20 % or more failure rate. However, I never really documented the performance from using rifle primers in the past.

So I decided to run a simple test using some small rifle primers I had on hand. The three I had on hand were some Winchester small rifle standard, some CCI 41 military small rifle, and some S&B small rifle standard. The CCI 41 are designed for military use to prevent slam fires in AR style rifles. I felt if I had any problems with any of them it would be with the CCI.

My original plan was to pick one bullet, one powder, and one case changing only the primer. However, I was a little short in the bullet department not having enough of any single type. I picked three different bullets. The 115gr Hornady HAP, the Zero 124gr JHP, and the Remington 147gr JHP. I would load forty rounds of each bullet. Twenty with one type of small rifle primers and twenty of small pistol.

The powder I picked was Winchester Auto Comp. I had plenty on hand and I have worked with it enough in the past that I felt safe going directly to the top loads on Hodgdon’s website.

I have some new Lapua 9mm brass on hand and decided to use it in the test. Since I had some new brass on hand I felt it would help ensure consistent primer seating making sure if I did experience any misfires I could be sure it was the primer and not from improper seating. All primer seating was done on an RCBS bench mounted Automatic Priming Tool.

Two pistols were chosen for the test. A Glock 19 gen 3 and a Beretta 92 A1. The Glock was completely stock but the 92 A1 had a “D” spring installed. Both pistols are completely reliable with factory ammo and handloads with pistol primers.

I paired up the Remington 147gr JHP with the Winchester small rifle primer and 4 grains of AutoComp. 4 grains of AutoComp is the max load in the Hodegdon’s online load data. The Zero 124gr JHP was loaded with 5.4 grains of AutoComp and the S&B small rifle primer. Finally, the Hornady 115gr HAP was loaded with 5.6 grains of AutoComp and the CCI 41 primer. The above loads were also loaded with Winchester small pistol primers for comparison’s sake.

Starting with the 115gr Hornady, I measured each 5.6 gr charge with the RCBS Chargemaster. Twenty of the cases with the CCI 41 primers were loaded followed by twenty of the cases with the Winchester SP. This process was followed by loading the 124gr with the S&B SR and the 147gr with the Winchester SR.

Setting up the Caldwell G2 Chronograph at 10 feet I started with the Remington 147gr and the Winchester small rifle primer. I was only able to record 5 rounds over the chrony. With the five shots, I got an average velocity of 888 fps. This was quite a bit less than the load data suggested of 916fps. The low was 866fps and the high was 905fps for an extreme spread of 39fps

Shooting the same load with the Winchester small pistol primer had an average of 858fps With a high of 869fps and a low of 830 and an extreme spread of 39fps also. This time I was able to get readings from all ten rounds. There was no sign of pressure with either load and in fact, they showed signs of under pressure with soot on the cases. There were no issues using the rifle primers and in fact, it boosted velocity a bit over the standard small pistol primers by 30fps when comparing the average velocity.

Performance out of the Beretta 92 A1 was also without any problems and with lower than expected velocity. The Remington 147gr bullet load with the Winchester small rifle primer had an average velocity of 882fps with a high of 987fps and a low of 880fps and an extreme spread of 17fps. With the Winchester small pistol, I achieved an average velocity of 863fps with a high of 904fps and a low of 849fps.

That is where the success ended. Both the CCI 41 and the S&B primers had difficulty going off with both pistols. With the S&B the Beretta was only able to set off 4 of the 10 rounds. The average velocity is 1112fps. In the Glock, I was able to get 7 shots off and got an average velocity of 1104fps. This was with the Zero 124gr JHP loading.

If I thought the S&B small rifle primer was bad, the CCI 41 was even worse. I was only able to get one round off with each pistol using the Hornaday 115gr HAP loading.

Unfortunately, I didn’t have any Federal, Remington, or CCI standard small rifle primers to try out but I have used Federal SR in the past and it worked fine.

I did however have several different powders on hand and decided to try out the Winchester small rifle with a few of them. The sticking point again was bullets. Digging around I found some Sierra 115gr JHC I was planning on working with. I decided to just use them up so I could do some more testing.

I used two powders this time, Winchester 231 which is a little faster than the Auto-Comp, and Alliant Power Pistol which is on the slower side. Like last time I used new Lapua cases and loaded twenty rounds of Winchester small rifle and twenty rounds of the Winchester small pistol primers for each type of powder for a total of 80 rounds. Using Sierra’s load data I went straight to the max loading for both powders. Not the normal way to do things but if there was a pressure issue between the primers, it should show itself at the max charges.

Starting with the Glock 19 and Winchester 231 powder, with the Winchester small pistol primers, I got a 10 shot velocity average of 1176fps. A high of 1193fps and a low of 1166fps and an extreme spread of 27fps. When shooting the same load using the Winchester small rifle primers the average was 1186fps with a high of 1205fps and a low of 1168fps and an extreme spread of 37fps. In this case, the rifle primer gave an increase of 10fps average. There were no signs of excessive pressure with either loading.

Now, switching to the Allant Power Pistol loading. With the Winchester small pistol loading the average velocity was 1281fps with a high of 1324fps and a low of 1237fps giving an extreme spread of 87fps. switching to the Winchester small rifle primer the average velocity was 1282fps with a high of 1332fps and a low of 1246fps and an extreme spread of 86fps. Both the small rifle and pistol loadings showed signs of overpressure.

The results for the Beretta weren’t much different. The Winchester 231 loading using The Winchester small pistol primer gave me an average velocity of 1170fps and a high of 1183fps and a low of 1152fps with an extreme spread of 31fps. Using the small rifle primer the average velocity was 1171fps with a high of 1182fps and a low of 1158fps giving me an extreme spread of 24fps.

Now the Power Pistol load in the Beretta. I had a chronograph issue with the small pistol primer load and was only able to get the velocity of the last round and it was 1307fps. When using the small rifle primer I got an average velocity of 1314fps and a high of 1349fps and a low of 1275fps giving an extreme spread of 74fps. Just like in the Glock 19, excessive pressure was seen with both primers.

Since all loadings with the Power Pistol powder showed signs of higher then normal pressure I think it’s safe to say this is from using a max charge of powder and not from the type of primers used.

It would appear that substituting small rifle primers in the place of the small pistol is a viable option. However, not all small rifle primers are the same. Testing and working up a load as normal would still be necessary but if you can’t find small pistol then small rifle is a possibility.

One comment

  1. Primers need two things for reliable ignition. They need to be hit hard and they also need to be hit at very high speed. Primers are tested in a holding drop fixture where a 2 oz. steel ball is released in un-retarded free fall before striking the fixture. If memory serves me correctly initial testing is from a height of 20 inches which gives 40 inch-ounces of energy when it arrives at the fixture.

    So, a 20 ounce steel ball dropped from a height of 2 inches will give the same amount of energy upon arriving at the fixture. So what is the difference? Isn’t forty inch ounces always equal to forty inch ounces? Not exactly, because you will not obtain ignition in the second scenario because the 20 ounce ball has not gained enough velocity prior to striking the test mechanism and the fixture did not obtain enough velocity to initiate ignition. Having only one without the other is useless.

    In the industry they endeavor to firmly establish the “All Fire Drop Height” which is the lowest height the ball can be dropped and obtain 100% ignition reliability. In testing primers the height the drop ball is reduced an inch at a time until they achieve what is termed the “All-No Fire Drop Height.” Once that is determined the primer receptacle by a “copper” receptacle which looks exactly like a headspace gage, but has a flat bottomed hole in the bottom (where you would look for a primer in a loaded round) about 3/8” deep. There will be a hole, about .075”-.080” drilled all the way through to push the copper back out (from the front) for bench inspection measurement of the striker indent. The “C” size copper used by the government for 9mm and 5.56mm is a .225”x.400” annealed copper cylinder.

    The copper is placed so as to receive the energy departed by the striker nose and the ball is dropped at the same height they experienced the all no fire condition, averaging ten samples. After removing the coppers they are placed on the anvil of a bench inspection gage rigged with a sharp pointed stylus that will reach the bottom of the indent without touching the sides. The indent depths are measured in thousandths of a inch and averaged. In 9mm the All No Fire Indent (ON COPPER) is .007” whereas the All Fire Drop Height will exhibit .012” indent (ON COPPER).


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