Mak Loads and Magnum Primers

[The Only Sarge]

First the disclaimer
I AM NOT ADVOCATING NOR RECOMMENDING USING MAGNUM PRIMERS.
I AM JUST SHARING.

OK....

For giggles I took my regular Makarov load of 3.5g TiteGroup 95g Hornady XTP
.970 OAL and used 2 things different.
1. I used Small pistol magnum primers
2. I used my new Lee 9X18 Mak Factory Crimp Die

Shot the first 10..............
Chrony tells me 1085 FPS. Very consistent with less than 10-15 FPS amongst them.
No pressure signs at all.
No noticeable additional recoil or muzzle blast.

Just my results for whatever it is worth.

[frankmako]

i use magnum primers when i run out of standard primers. back when primers were hard to get is when i changed over to using them. i ran several different loads/cals across my chronograph and found that i was getting about 50 fps more with the magnum over the standard ones.

[juniustaylor]

They can be used with no ill-effects but I believe load manuals stress dropping the charge a certain percentage. Probably drastic but if one didn't take into account the difference between the two and were already at a max charge and substituted a magnum primer, that 50 fps could be the difference between boom and kaboom.

Just with .357 Magnum there's quite a difference. With Power Pistol, 10.5 grains of it with regular CCI 500 says 1345 FPS. According to Lyman, 10 grains of PP with CCI 550 (mag) primers is 1479 fps. That's a huge difference in velocity and considering the charge is even 1/2 grain less. I'll chrono these to see what I get if I actually get close to 1479. I was getting an average of 1320 fps with 9.6 gr Unique with regular Win WSP primers.

[frankmako]

yes you should drop the charge when using mag primers. i don't because my loads are at the bottom and the 50 fps increase don't put my load much more into the midrange in the reloading data. i shoot a lots and i keep all my reloads in the lower end of their fps. easy on the old hands and more fun to shoot.

[juniustaylor]

You are right about that. The lower loads are more fun to shoot. Less recoil and most times more accurate!