Using small rifle primers instead of small pistol

[Tackdriver VillenTactical]

So I am just about out of small pistol primers and am not paying $100/1k. for more. I will now be making loads with small rifle primers. So how do I start developing my loads, 10% less powder, 20, 30? I have no idea.

Dave

 

[Finalygotabeltfed]

I've been using SR primers in 9mm for years with no reduction in charge and haven't noticed a bit of difference.

I've alternately loaded rounds with SP and SR primers into mags fired in a subgun and there was no difference in the report or the accuracy.

I actually stopped buying SP primers altogether until just recently, wanting to try out some of the Wolf primers just too see how they performed.

If you are that concerned, a 10% reduction would be more than adequate and work up from there. I don't think you'll find much difference in the final product though.

EDIT: Actually, I've used SR primers for all small pistol applications without any problems.

 

[Tackdriver VillenTactical]

Great, Thanks.

Dave

 

[eisenhow]

If you search I think EddieCoyle actually did some chrono testing with the same load with small pistol and small rifle primers. IIRC the difference was in the noise. I can't seem to find it now.

 

[EddieCoyle]

I tested this with a load of 3.0 gr of Bullseye behind 148 gr wadcutters in a .38 Special. I chrono'ed the loads and found that the rounds primed with the small rifle primers ran 4 fps faster than those with the small pistol primers. In other words, there was no difference.

 

[drgrant]

Do the SR primers mic out to be a different diameter than SP primers? Or are the pockets/primer size virtually the same?

-Mike

 

[EddieCoyle]

The small primers the same diameter and height, so as far as size goes, they're interchangeable. The large primers are not the same size - the rifle primers are longer.

 

[TY43215]

USPSA Shooters have been using SR primers in place of SP primers for a long time. The adjustment I was taught was .2gr less powder