video testing substituting small rifle or small pistol mag for SPP

[greyling22]

the question "can I use small rifle or small pistol mag instead of small pistol primers" asked periodically, especially when primers are tight, so i stumbled across this video on the reloading subreddit today. I don't know this guy, never heard of his ammo company, but he pressure tests and chronographs a few loads that were identical except for a primer swap.

It is not exhaustive testing, but it is some actual data behind of many seasoned reloaders have said "I have used them with no issue"


The short of it is that there is no pattern of increased velocity or pressure that emerges in his small sample set.

 

[Blue68f100]

If your not at max load, you should be fine if your gun can set off the harder caps. May get a boost in velocity depending on the load. SP Mag primers are probable the equivalent of a SR primer.

 

[Carl N. Brown]

Small pistol magnum primers and small rifle primers tend to have thicker cups and more priming compound than small pistol primers.

9mm pistol factory ammo use SPP.
I have found that SPM and SRP did not fire in a light carry subcompact 9mm but SPP and did.
I have found my C96 (with a Wolfsprings hammer spring fires 100% with all three small primers.

If a load is pushing maximum with SPP, using SPM or SRP could go over.

 

[Carl N. Brown]

Whether Small Pistol Magnum and Small Rifle Primers are exact equivalent may depend on the manufacturer and may change.

 

[fxvr5]

FYI, This has been posted several times already.

 

[greyling22]

FYI, This has been posted several times already.

oops. didn't know that.