primer mix-up

jetrecbn1 · August 8, 2000, 10:15 PM

What would happen if small rifle primers found their way into your pistol loads? Would the small rifle primer act like a small magnum primer?

char923 · August 8, 2000, 11:28 PM

I use small rifle primers in my 9X23 IPSC loads, the main reason is because the cup on the primer is thicker and will handle the pressure of the loads.

Bottom Gun · August 9, 2000, 10:53 AM

I wouldn't worry about it. I use rifle primers for both rifle and pistol. The only difference, so I'm told, is the jacket on the rifle primers is slightly thicker material. I haven't been able to tell the difference in my loads.
You would NOT want to use pistol primers for rifle cartridges though.

Southla1 · August 9, 2000, 02:22 PM

One thing to watch out for, is that sometimes the blow of the firing pin in a pistol is weaker than in a rifle, which could cause a misfire because the cup is harder in rifle primers. Other than that if you do what you should do anyways, which is start low and work up your loads, it should cause no problems whatsoever.

**Mal H** · August 9, 2000, 02:46 PM

Bottom Gun - The cup thickness is not the only difference. Rifle primers are slightly "hotter" than the same designation in a pistol primer. I proved that to myself a while back when I experimented with standard primers of each type. I shot rubber bullets powered only by a primer over a chronograph. The rifle primers consistently yielded 10% to 20% higher velocities, IIRC. I compared lrg rifle to lrg pistol and sml rifle to sml pistol.

The caveat is to (as always) lower your powder charge at least 10% when changing primer type (or even primer manufacturers of the same type) and work back up to a safe load just as Southla1 said.

Chris McDermott · August 11, 2000, 04:57 PM

Large Rifle and Large Pistol primers also have a difference in "height" of the cup; Large Rifle are slightly taller. So don't use Large Rifle primers instead of Large Pistol, or you will have problems with protruding primers or perhaps setting one off in your press. This isn't a problem with the small rifle & pistol primers.

Bottom Gun · August 14, 2000, 12:20 PM

Those are some very interesting points. I’ll have to experiment a little and see if I can see a difference through the chronograph.
Never knew there was a dimensional difference either. I don’t have any pistol primers here to compare right now. Is there a dimensional difference in both large and small rifle vs pistol primers? How much difference is there?

**Mal H** · August 14, 2000, 12:59 PM

I just verified Chris McDermott's statement on the height of the cups.

All CCI primers were used in this comparison.
Large rifle = .117"
Large pistol = .110

Small rifle and small pistol were the same at .111"

The difference between the large primers is significant and could, as he said, leave a large rifle primer above the case head or cause you to crush the primer pellet and cause a misfire.

Bottom Gun · August 14, 2000, 04:02 PM

Very interesting.
Looks like I'd beter pick up some large pistol primers.
Thanks for setting me straight on that, Guys.

August 8, 2000, 10:15 PM	#1
jetrecbn1 Senior Member Join Date: March 13, 2000 Posts: 200	What would happen if small rifle primers found their way into your pistol loads? Would the small rifle primer act like a small magnum primer?

August 8, 2000, 11:28 PM	#2
char923 Senior Member Join Date: February 18, 2000 Location: Anchorage AK Posts: 237	I use small rifle primers in my 9X23 IPSC loads, the main reason is because the cup on the primer is thicker and will handle the pressure of the loads.

August 9, 2000, 10:53 AM	#3
Bottom Gun Senior Member Join Date: October 13, 1998 Location: Arizona Territory Posts: 1,092	I wouldn't worry about it. I use rifle primers for both rifle and pistol. The only difference, so I'm told, is the jacket on the rifle primers is slightly thicker material. I haven't been able to tell the difference in my loads. You would NOT want to use pistol primers for rifle cartridges though.

August 9, 2000, 02:22 PM	#4
Southla1 Member In Memoriam Join Date: March 19, 2000 Location: Jeanerette, La. Near the Posts: 1,999	One thing to watch out for, is that sometimes the blow of the firing pin in a pistol is weaker than in a rifle, which could cause a misfire because the cup is harder in rifle primers. Other than that if you do what you should do anyways, which is start low and work up your loads, it should cause no problems whatsoever.

August 9, 2000, 02:46 PM	#5
Mal H Staff Join Date: March 20, 1999 Location: Somewhere in the woods of Northern Virginia Posts: 16,949	Bottom Gun - The cup thickness is not the only difference. Rifle primers are slightly "hotter" than the same designation in a pistol primer. I proved that to myself a while back when I experimented with standard primers of each type. I shot rubber bullets powered only by a primer over a chronograph. The rifle primers consistently yielded 10% to 20% higher velocities, IIRC. I compared lrg rifle to lrg pistol and sml rifle to sml pistol. The caveat is to (as always) lower your powder charge at least 10% when changing primer type (or even primer manufacturers of the same type) and work back up to a safe load just as Southla1 said.

August 11, 2000, 04:57 PM	#6
Chris McDermott Senior Member Join Date: March 30, 2000 Posts: 245	Large Rifle and Large Pistol primers also have a difference in "height" of the cup; Large Rifle are slightly taller. So don't use Large Rifle primers instead of Large Pistol, or you will have problems with protruding primers or perhaps setting one off in your press. This isn't a problem with the small rifle & pistol primers.

August 14, 2000, 12:20 PM	#7
Bottom Gun Senior Member Join Date: October 13, 1998 Location: Arizona Territory Posts: 1,092	Those are some very interesting points. I’ll have to experiment a little and see if I can see a difference through the chronograph. Never knew there was a dimensional difference either. I don’t have any pistol primers here to compare right now. Is there a dimensional difference in both large and small rifle vs pistol primers? How much difference is there?

August 14, 2000, 12:59 PM	#8
Mal H Staff Join Date: March 20, 1999 Location: Somewhere in the woods of Northern Virginia Posts: 16,949	I just verified Chris McDermott's statement on the height of the cups. All CCI primers were used in this comparison. Large rifle = .117" Large pistol = .110 Small rifle and small pistol were the same at .111" The difference between the large primers is significant and could, as he said, leave a large rifle primer above the case head or cause you to crush the primer pellet and cause a misfire.

August 14, 2000, 04:02 PM	#9
Bottom Gun Senior Member Join Date: October 13, 1998 Location: Arizona Territory Posts: 1,092	Very interesting. Looks like I'd beter pick up some large pistol primers. Thanks for setting me straight on that, Guys.