Primer thickness observations

[J Miller]

Earlier this year I bought a 1000 Magtech #9½ LR primers. Not having ever used this brand before I was curious and here is what I've found so far.

We all know, or should, that LR primers are thicker (taller) than LP primers. Generally speaking if you try to seat a LR primer in a pistol cartridge you'll get a high primer condition, and if you try to seat a LP primer in a rifle cartridge you'll get a low primer. Not always, but generally.
Well, the Magtech LR primers are thinner than standard American LR primers. Actually so close as to be LP size. I've primer 20 rifle cases with them so far and they had no feel of bottoming out in the primer pockets.

So to find out what's up with them, I measured the Magtechs and a couple of each different primer brand I had for thickness and here's my list:

LR
Winchester Blue Box Brass.... = .1297"
Winchester White Box Plated. = .1262"
Federal ............................... = .1325"
CCI..................................... = .1262"
Magtech.............................. = .1222"

LP
Remington.......................... = .1213"
CCI.................................... = .1211"
Winchester Blue Box Brass... = .1182"
Federal............................... = .1175"

I suspect that if someone was short on LP primers and had some of the Magtech LR primers they could substitute them. I'm going to try then in the next box of .45 Colts I load. It should be interesting.

Joe

[AJMD429]

Isn't the metal itself also thicker on 'rifle' primers, or is that just on 'magnum' ones, or what...?

I have two guns (a Rossi 92 and the Ruger 77) that make very deep dents in primers (like shotgun firing pins do), and due to that occasionally cause one to crack. I'll take a little off the firing pins if I can be sure the bolt face inside and the shoulder area on the pin are ok, but I wondered if 'rifle' primers would work better in the interim.

[mikld]

What measurement is this? Diameter? Height? Or thickness of the cup material?

[J Miller]

Isn't the metal itself also thicker on 'rifle' primers, or is that just on 'magnum' ones, or what...?

I have two guns (a Rossi 92 and the Ruger 77) that make very deep dents in primers (like shotgun firing pins do), and due to that occasionally cause one to crack. I'll take a little off the firing pins if I can be sure the bolt face inside and the shoulder area on the pin are ok, but I wondered if 'rifle' primers would work better in the interim.

I've heard the LR primers had a thicker cup as well as being taller. Then again I've heard the cups are the same and only the height was different.
I honestly don't know for sure.
I'm going to load 50 of these Magtech LR primers in some .45 Colt case and try them in my .45s. It might be a waste of time, then again, it might not.

What measurement is this? Diameter? Height? Or thickness of the cup material?

Height.


Joe