[Foerster]

OOPS! I accidentally bought small pistol magnum primers instead of match primers (Federal). They are the same diameter, but the manufacturer web site says they are for high velocity. The bullets I am making are .40 cal. light loads for match shooting. Is there really a difference?

[Mark K]

There have been a few threads on this subject, and the gist is that using magnum SPP will add about 5PF to your loads, and that is about it.

Mark K

[Foerster]

I thought it might not be a big deal. The magnums were $5/1000 cheaper too.

[kgunz11]

Dang David, had you called me I could have held the order for you and replaced them with regular small pistol.

In a nutshell, because of the low flash temperatures associated with small pistol primers, the difference between a small pistol and small pistol magnum primer is very small. Now on the other hand, the difference between large rifle and large rifle magnum is quite substantial, as it is a much larger dose of chemical. You'll be fine with the SPM primers.

If I hadn't become such a nazi about getting shipments out immediately, I could have fixed it. This is one of those times fast shipping isn't that good.

[GrumpyOne]

I've used them with no ill effects!

[kgunz11]

BTW, I actually recommend them to Open shooters using slower burning powders. It is my opinion that they give more consistent ignition with the slower burning powders which leads to better chrono numbers.

[G-ManBart]

They should work fine, but keep one thing in mind. With very light loads it's possible that they won't seal in the primer pocket properly and allow hot gasses to leak around the primer. When that happens it erodes a circular cut into the breach face, which isn't good. Just make sure you check the breach face after you've shot 50 or 100 and take a look that the head of the cases don't have obvious soot on them around the primers. This is more of a problem when using small rifle in light pistol loads, but it can happen with SPM as well. R,

[Foerster]

kgunz11, on Aug 31 2009, 08:51 PM, said:

Dang David, had you called me I could have held the order for you and replaced them with regular small pistol.

In a nutshell, because of the low flash temperatures associated with small pistol primers, the difference between a small pistol and small pistol magnum primer is very small. Now on the other hand, the difference between large rifle and large rifle magnum is quite substantial, as it is a much larger dose of chemical. You'll be fine with the SPM primers.

If I hadn't become such a nazi about getting shipments out immediately, I could have fixed it. This is one of those times fast shipping isn't that good.

Your web site said all other primers were sold out. Besides the magnums were cheaper. Thanks for the info and the primers. All is good

[Aircooled6racer]

Hello: The small magnum primers is what the cowboy shooters use for there revolvers and rifles for 38's. They can lower the power facter so the 38 revolver bullet will not go through a paper target The magnum primer does give you about 15-40 ft/s velocity change over the standard primer in 40 major and 9mm minor loads. Since you have them shoot them up, you may like them Thanks, Eric

[islandracing]

kgunz11, on Aug 31 2009, 10:59 PM, said:

BTW, I actually recommend them to Open shooters using slower burning powders. It is my opinion that they give more consistent ignition with the slower burning powders which leads to better chrono numbers.

I use Winchester 231 which is a relativley slower burning powder and I get a better standard deviation on the loads when using the small magnum primers over the standard. The effect on velocity is minimal. I probably would not recommend using them with the fast burning powders like Solo 1000 without testing.