Primer Question - Small Rife - Small Pistol

[frankmako]

Been reloading for many years and now I have a guestion about primers. Can you use rifle primers in place of pistol primers?

I have used mag primers in the place of standard primers many times in my pistol loads. Over the chronograph I get between 35 to 55 fps more in the loads. But with small pistol primers getting hard to find I was thinking of using small rifle primer in there place. Same with large pistol also.

Never put much time into this before untill now with primers hard to find.

[DefensiveCarry.com]

[Jeff F]

Take you mic and measure the thickness (height) of the rifle primer compared to the pistol and you'll see that the rifle is taller. It will stick further out of the pistol primer pocket. Depending on how the primer pocket is cut may not be an issue but if it's cut tight on the SAAMI specs than it's probably not going to work safely.

I shoot a lot of BPCR and a lot of guys use pistol primers in their rifles. Problem is that when the cartridge goes off the in set primer will set back against the breech block and over time will start to crater it supposedly. Personally I don't know I usually stick to the way it was designed to be used.

[Cupcake]

As I understand it, rifle primers have more ooomph, to ignite more of the powder faster. Igniting more of the pistol powder faster might cause higher pressures? I guess none of that matters if they don't even fit, which I did not know.

[cvhoss]

First, IIRC, Jeff F is correct in that there is a small difference in height.

Second, I've never felt comfortable exchanging components like that. The way I look at it, if they were interchangeable why would the manufacturers bother with producing two different components.

And third, unless you have a supply of small rifle primers on hand, it's probably not going to be any easier to find them as they're a .223 component and anything .223 is next to impossible to find right now.

Hoss

[mcp1810]

My understanding FWIW......
Dimensionally small rifle and small pistol primers are the same. The energy when they detonate is not. Rifle primers have more oomph. Also rifle primers are made with thicker cups so as not to blow out from the higher pressures common in rifle cartridges. If your mainspring isn't fresh or if you use a reduced power spring to improve your trigger pull you are going to be more prone to misfires using rifle primers than pistol primers.
Large rifle primers are the same diameter as large pistol primers but are a little taller.
Conversely you would never want to use pistol primers in a rifle cartridge because they will be much more likely to blow out as they are not designed to be used at those pressure levels.

[Jeff F]

Well after reading some of the replies I had to pull out a bunch of primers and do some figurin'. Of course I gotta say believing something doesn't always make it true or correct, so i need to do some verifying. Here's the results.

Winchester - Small Rifle .1190 Small Pistol .1197

Federal - Small Rifle .1200 Small Pistol .1220

So that would tell me that mcp1810 is absolutely correct in what he's saying, but the kicker is the first primers that I measured was CCI which happens to be the ones that were on top of my primer pile and their measurements were Small Rifle .1215 Small Pistol .1180. Now this measurement is somewhat similar to what the measurement is for large rifle primers compared to large pistol primers. Federal Large Rifle .1270 Federal Large Pistol .1200. So take it for what it's worth, but I still think the best advice is to stick to what was made for a particular application and use it for that application and don't mix components when loading.

BTW this has been a great discussion and I've been loading for 30+ years and find out new things all the time. Thanks everyone.