Small Magnum Primers In .40sw

[BBoyd]

I inadvertantly loaded some .40's with small magnum primers instead of regular small primers. Anyone know what problem these could cause? Throw them out or shoot them up?

[Guy Neill]

A lot depends on where you are with the powder charge. If a maximum load, I would not shoot them unless I first tried some loaded lighter.

The magnum primers are quite a bit more powerful than standard primers and will affect the ignition. They may be powerful enough to move the bullet, then having the powder gases catch up. The larger and longer duration flame will also light more individual powder granules initially, evolving more gas faster than a standard primer.

Unless you have loaded a large quantity, I would disgard or salvage.

Guy

[MikeFoley]

I used 2000 of them a while back with 4.7 grains of VV N320 and they increased my velocity 10 fps over small pistol primers. A lot of guys use rifle primers too.

Like Guy said, it really depends on where you are with the powder. If you are hot loaded already, then it is dangerous. If this is the case, then don't riske it.

If you are loading near the power factor floor like most, then you won't even notice the difference. If this is the case, I say shoot one through the chrono and use them.

[Big Shooter]

I found the Mag primers made a difference of about 40-50 fps. I was using 4.7 of Titegroup, 1.2" OAL, w/a 180 grn bullet. About 10K or so through 2 different guns now & no problems. They cost the same as regular primers, so I figure the little boost can't hurt.

Just at the range the other day w/new SC from Brazos Custom. (The most kick-a$$ gun I've ever owned, BTW.) Anyways, same load through Brazos gun gives me about 40 more fps vs. a Para P-16.

Through the Para, 4.8 of TG gave me a PF of about 168-170. Same load through my Brazos gun is about 173-175 PF. I also lengthened it to 1.22" at Bob's suggestion. One of these days I have to drop the powder charge a tenth or two, get back to the range and see what effect that has.

[Harmon]

I found the Mag primers made a difference of about 40-50 fps.  I was using 4.7 of Titegroup, 1.2" OAL, w/a 180 grn bullet.  About 10K or so through 2 different guns now & no problems.  They cost the same as regular primers, so I figure the little boost can't hurt.

Just at the range the other day w/new SC from Brazos Custom.  (The most kick-a$$ gun I've ever owned, BTW.)  Anyways, same load through Brazos gun gives me about 40 more fps vs. a Para P-16.

Through the Para, 4.8 of TG gave me a PF of about 168-170.  Same load through my Brazos gun is about 173-175 PF.  I also lengthened it to 1.22" at Bob's suggestion.  One of these days I have to drop the powder charge a tenth or two, get back to the range and see what effect that has.

<{POST_SNAPBACK}>

how bout you go back to regular primers?

[Big Shooter]

That's one of the things I'm gonna try, just as soon as I go through the 7 or 8 thousand mag primers I have stockpiled. (Unfortunately, that will probably take all year.) Still, 10 thousand or so w/mag primers, and not even a hint of a problem.

Not in a huge rush to change loads again. I hate to spend what little time I can at the range experimenting with a chrono when I should be just shooting, which I don't do enough of, anyway.