Large magnum rifle primers for the S&W 500?

[Bigmike60411]

Please excuse me, this is my first time ever posting anything anywhere.
So I loaded up 40 shells with Remington 9 1/2m (magnum) primers before I realized I bought the wrong primers. I'm loading Titegroup 15 grain with a 440 lead bullet (gas checked). Min load is 14.5, max load is 16.5 grain. I figured 15 is middle of road. Will I be SAFE with the magnum primers or do I have to pop them out and put in standard?

 

[Doubless]

The rule of thumb is that going from standard to magnum primers one should back off approximately one grain in powder charge. I extrapolate that to your current charge with the magnum primer being the equivalent of 16 grains of Trail Boss, all other things being the same. You should still be okay.

The biggest difference between rifle and handgun primers is the cup thickness, and that is to accommodate the difference in pressures between handguns and rifles.

 

[STCM(SW)]

All the new 500 Magnum brass I have calls for rifle primers.....

 

[Kilibreaux]

Cases made for rifle primers have a deeper primer pocket. If your cases have an "R" on them they should be carrying rifle primers.
As for magnum versus standard, depending on brand, magnum primers can be the difference in a thicker cup, or slightly - and I mean SLIGHTLY greater priming charge.
Consider that the .500 Magnum was designed to handle an "average working pressure" of 60,000 CUP, and you will find FEW loads that push it much above 40,000 CUP, even if you've shoved in "magnum" rifle primers, unless you started at the highest powder charge you can find (which you did not), you're okay. 15 grains of Titegroup should be pressure out around 45-47K CUP, but you are still about 1.5 grains BELOW an approximately 50K CUP load with standard primers at 16.5 grains of Titegroup....you're safe.

 

[BLUEDOT37]

Titegroup & 500S&W

Will I be SAFE with the magnum primers or do I have to pop them out and put in standard?

You are fine. The Hodgdon website shows they used WW Magnum Large Rifle primers when they worked up their data for the 500. Just be careful & double check your powder throw weights. You don't want to accidently get a double charge of that fast powder in that huge case.

Concerning the use of large pistol primers in the 500, when I loaded reduced loads that were documented at 36K psi or below, I used large pistol primers without issue in S-L (R) cases. If undocumented psi or unknown/in doubt, I used large rifle primers.

 

[Bigmike60411]

Thanks guys! Thought I'd be ok, but just wanted to verify.