9mm with (got lucky earlier last year): ~5000 Small Pistol Magnum Primers (NOT LOOKING TO SELL/TRADE) SMPP (SPPM/SMPP?)

LinuxAssailant

New Member
Dec 1, 2020
17
13
California, for now.
I bartered away some SPPs for some rifle powder I like, and was short on, but have almost a full case of small magnum pistol primers SMPP (SPPM?), but mostly reload 9mm, as we have 3 guns that use them...

How much should I back off my load when using SMPP?

Load data (Hogdon site) says 3.8 to 4.4 Universal for 124gr projectiles.
Lee Second edition has similar data for 100gr frangables (3.8 - 4.2gr Universal).

Assuming conservative lawyer data, as the max speed for 124gr lists 1045 FPS with 4.4gr on Hogdon,
Should I even back-off 4.0gr of universal with 124gr projectiles, if I use CCI Small Pistol Magnum Primers?

I have been using right-at the same data for 115gr FMJ, 124gr X-treme plated FP, and 124gr Acme 124gr RN with S&B/CCI SPP.

During the last shortage, I did test CCI #41 Hard Cup Small rifle primers in 9mm, and small pistol primers (various) in .223/5.56, w/out issue.
As I recall, #41's chrono'd about + 50-75 FPS in 9mm with the same charge.

The .223/5.56 I did not chrono, but they shot as well as I can shoot with iron-sights in a 1:8 20" AR.

Thoughts?

Please advise...
 
Last edited:

Dawico

Uncoiled
Lifetime Member
Oct 15, 2009
35,033
113
Lampasas, Texas
I hear load as normal and I hear drop down 10%.

Personally I load mid range charges in most handguns and wouldn't adjust for Magnum primers. But I'd only load a few and see how they feel.

If I was loading full power I'd go with the 10% down and try a few out.

That's just me though.
 

Younggun

Ginger Avenger
TGT Supporter
Admin
Jul 31, 2011
51,501
113
hill co.
I picked up some by mistake once. In my experience with the powders I was using it didn’t make any noticeable difference in velocity or pressure.

Velocity checked with a chronograph. Pressure was only assumed by eyeballing the primers and cases for signs of overpressure although I believe magnum primers are supposed to have a harder cup anyways so it probably wouldn’t show.


Sent from my iPhone using Tapatalk
 

BigTexasOne

Support gun control! Hit what you aim at!
Apr 27, 2016
980
63
Springtown
I never load to max, I try to stay moderate in all my loads, so for me, it doesn't matter which primer I use.
 

TexMex247

TGT Addict
TGT Supporter
May 11, 2009
2,677
83
Leander(NW Austin)
If you aren't loading near max don't sweat it. I've even used small rifle primers in 9mm using titegroup with no issues. They actually had a slightly lower SD, no pressure signs and almost identical velocities. Only thing you may run into, depending on brand...magnum primer cups are harder and may cause malfunctions in striker fired guns.
 

hornetguy

Member
Feb 21, 2021
74
18
Allen, Texas
If you can stand youtub, there's a video on there where a guy had a chamber pressure unit, and he tested the difference between primers, everything else equal... he found no difference in pressure, and no difference in velocity. Same loads, everything. You should be good to go with regular loads. That's what I plan to do when I get down to that point.
 

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