What's the Difference - Small v. Large Pistol Primers?

[Bubbajms]

Newbie to reloading, and I was out shopping and asked. The guy I talked to didn't know. Still haven't got my stuff set up, but trying to learn..

 

[Joe Williams]

Most obvious difference is the physical size.

Here's a neat article on primers. A primer primer, if you will

Primers, the Sparkplug of Centerfire Cartridges

 

[Bubbajms]

I kinda figured that, Joe

Are the sizes cross-compatable?? Just generally, for example - could I use either size in Caliber X, or is Caliber X going to use small primers and Caliber Y going to use large ones? If that's the case, is there a chart that says .38 = XX Size, 9mm = YY Size, etc?

Handle the newbie (and reloading components) with care!

 

[Indy_Guy_77]

I've read (on here, I think?!) that .45ACP = large pistol primers

Whereas 9mm and .40 use small pistol primers. I would presume, then, that .38Spec and .357 also use small due to the similar case diameters to the 9mm.

BUT, I am NOT sure if the primer issue is dependant upon case diameter or overall case VOLUME.

YOU, sir, have posed a very good question!

-J-

 

[Joe Williams]

I kinda figured that, Joe

Are the sizes cross-compatable?? Just generally, for example - could I use either size in Caliber X, or is Caliber X going to use small primers and Caliber Y going to use large ones? If that's the case, is there a chart that says .38 = XX Size, 9mm = YY Size, etc?

Handle the newbie (and reloading components) with care!

Oh LOL

.38 Special, .357 Magnum, 9mm small pistol
.45 ACP large pistol.

Frankly I'd have to break out my reloading manual for other calibers. Do you have a question about a particular caliber?

 

[Bubbajms]

Just wondering in general, Joe.. as of now, I have the dies for 9mm, .38/.357, and .44. I'm thinking (once I learn all this) that I may pick up .40/10mm as well.

 

[Joe Williams]

Just wondering in general, Joe.. as of now, I have the dies for 9mm, .38/.357, and .44. I'm thinking (once I learn all this) that I may pick up .40/10mm as well.

I've never seen an actual chart... I think people just kinda soak it up from the manuals.

A chart would be neat, though, if there is one out there!

 

[Joe Williams]

Closest I've been able to find on Google is the following chart, looking at the primer plug/sleeve column. Doesn't tell you rifle or pistol, but in MOST cases it's self explanatory.

RCBS - Precisioneered Shooting Products - Reference Tables

 

[EvilElmo]

.40 S&W does indeed use small primers.

 

[jimbo-indy]

Large pistol primers are used in 45ACP, 45 (long) Colt, 44 SPL and mag and larger pistol rounds. Generally, 44 and up use large, 40/10 mm and smaller use small primers. You don't have a choice as the primer size is determined by the diameter of the primer pocket in the case. The choice between the regular or magnum variety of small or large primers is determined on your load. This gets into amount of powder, type of powder and other variables. Best practice is to follow the data in reloading manuals. There are even special cases where you use small rifle primers in some pistol loads, i.e. 357 Maximum and some 454 Cassul. Yes, there is some 454 brass that have small primer pockets just for using small rifle primers but that is a real speciallty.
Probably more than you wanted to know. I'll go away now.

 

[Bubbajms]

Good info - thanks all!!

 

[jdhaines]

.45 GAP uses small pistol primers, for the record.

Something to do with the design of the round to get full .45 ACP velocity and ballistics out of the smaller package.

 

[singlestacksig]

Oh LOL

.38 Special, .357 Magnum, 9mm small pistol
.45 ACP large pistol.

Frankly I'd have to break out my reloading manual for other calibers. Do you have a question about a particular caliber?

some makers, of some brass do make one size primer pocket in a caliber normally in the other..

You can get .45 acp brass that takes small pistol..

 

[chipdog4]

Winchester .45 NT (Non-Toxic) uses small pistol primers.

10mm uses large pistol primers, 40 s&w uses small.

Edit to add:


In a pinch, like current primer shoratges:
You can use Small rifle in place of small pistol, BUT NOT VICE VERSA due to softer cups on the pistol primers (semi auto rifles will empty the magazine from slam fires)
Same thing with Large rifle and large pistol.

 

[BE Mike]

I'm not trying to be dismissive or a smart alec, but just trying to see that you learn the right way. There are no short cuts when learning to reload. Instead of trying to build up a knowledge about reloading from asking basic questions here and there on the internet, I would suggest getting a reloading manual like Lyman's for example and reading the part at the front of it that describes the reloading procedure in detail. When you have your equipment and follow all the instructions for setup of the press, and dies, you can look up the cartridge in the back. Once you determine what cartridge and specific recipe you are going to load, you can look at that data and find the recommended primer, i.e. large or small rifle or pistol primer, and whether or not you will need a magnum primer for the particular load you are anticipating trying to duplicate.

 

[Bubbajms]

BE Mike, that's a very valid point. I'm trying to pick up some really basic information so I can go shopping, and a manual is at the top of the list..

 

[rookie0014]

before i got any thing i bought the new lyman and speer books read them front to back and then went shopping. that would be my plan if i was you then you will know what you want to get and don't. if not you will want to buy it all, so read then buy what you need and go home and load some. Then you will get hooked and go back to the store or drive all around and hit every store you know like i do and then buy it all.

 

[mmaddox]

In addition to books/manuals, a class and/or mentor would be an wise choice.