Home Forums Reloading Big Game Rifles When to use Mag Primers??

I have considerable reloading experience, but.....! I know that I should use magnum primers in magnum cases under all circumstances. However, how about cases of 30-06 capacity or less (60 gr of water or less). I regularly shoot a 270 with 60 Gr of H4831, but use a standard primer and get great results. How about a 6.5 Rem Mag with H4831? I have never seen or read much about this subject, except I recall an article by Rick Jamison, who I believe recommended a Mag primer be used in all cases where more than 50 grains of power were being used. Any benefit to using Mag primers during cold weather?
Anyone have any experiences or recommendations concerning Mag Primer vs standard primer?

You do not have to use mag primers just because the case say magnum. My 300WSM uses standard WLR primers but I use mag primers in my 25/06. I let the rifle tell me what it likes best. I have used standard and mag primers in below freezing weather without a problem. Mag primers are suppose to give a hotter flash of longer duration which is a good thing if needed but there is no hard and fast rule that says you have to use one or the other.Rick.

I use a mag primer when I get over 65gr of powder or so, or when I use ball powders (223 excepted).

Use the primer that tends to give the best accuracy if the primer appears to have an influence on it. Otherwise, use the primer that gives the best shot-to-shot velocity and/or pressure consistency. What I've found is that some loads in the same cartridge tend to do better with magnum primers and some tend to do better with standard primers. With most loads, however, it doesn't appear to make any difference.

There is one caution, however. With some loads, a magnum primer will increase the pressure anywhere from 1,500 psi to about 3,000 psi with respect to the same load using a standard primer. Generally, assuming accuracy stays good, this doesn't matter all that much unless one is already loading on the ragged edge.

I do not, by the way, switch primer types simply because of the propellant being used. My standard LR primer is the Federal 210, and I will use this with single-base stick propellants, double-base stick propellants, or spherical propellants unless the ballistics and/or accuracy are better with a magnum-type primer.

I generally don't even consider going to a Mag primer until the powder charge exceeds 60gr. The two exceptions to this are if I'm using a very slow powder for the cartridge or I'm using a ball powder (although I don't use Ramshot, I hear they're the exception to the ball/mag rule).

Of course if I get misfires, hang-fires or wild vertical stringing with a standard primer, then I'll drop the load a bit, try a mag primer and work back up.

As long as you can get good ignition with standard primers (watch the target for vertical stringing at longer ranges), they usually provide the best accuracy. However, if you're going to be hunting in very cold temps with a powder charge over 60grs, then a mag primer is good insurance, because even if it does cost a bit of accuracy at least you'll know it's going to work.

In cases the size of the 30-06 and 270, unless I'm using a ball powder or a very slow powder, I never use a Mag primer.

I use Mag primers in .270 and up. I've been doing so for nearly 20 years. I always shoot full throttle loads. My performance has always been excellent. I use mag primers in all others with 50 grains or more. Probally make very little difference but I like knowing I have a little better burn. 163 bc

I just use what the load book says!!

I have always been able to find an accurate load in the desired (book) speed range expected.

Mike

Keep in mind that all brands of primers have different burn characteristics. I have seen them all listed by burn rate in the past, but do not remember the exact placement. I do remember that the Federal Large Rifle Magnum Primer is the hottest typically available to American reloaders and is often recomended for the Ultramags or 378 Weatherby class cartridges. The CCI 250 magnum primer is considerably hotter than the CCI 200 standard rifle primer but is only slightly hotter or even comparable to some other brands of standard primers. I have found the CCI 250 to give excellant results in 30-06 class cartridges in combination with slow powders (4350's, 4831's, RL22 etc.). When stepping up to 4895, 4064, or 3031 in this class of cartridges I will switch to the CCI 200, which I also always use in the 22-250, 260, or 30-30.

I ran into an issue with this subject this past summer. I have always used standard primers and IMR powders in 06 size cases with great results. This summer I worked up a load for my 25-06 using H414 powder and standard primers. It shot well, but I had hang fires. Switching to magnum primers stoped the hang fires and the load shot great. I've read and heard that ball powder needs a magnum primer, now I know it's true.

So to answer the question; In 06 size cases, I use magnum primers with ball powders and standard primers with extruded powders. In the 7 Rem Mag I use magnum primers. In the little .222 Rem case I use benchrest primers and H322.

This is the 25-06 load using H414 that gave the hang fires. Simply changing to magnum primers cured the problem and it still grouped that well.

I may stand corrected on this, but my personal experience leads me to believe that the Winchester WLRM is every bit as hot, if not hotter than the Federal 215. I have compared in several chamberings, and the Winchester consistently yields slightly higher velocities with all other factors being the same. Regards, Eagleye.

That's the way I see it.

The WLRM tends to produce the highest pressure and velocity, followed by the GM215M, with the 215 and R-P 9-1/2M being about equal (neither of which are all that much hotter than the standard Federal 210), with the CCI 250 the mildest of the magnum primers.

Of the standard primers, the WLR, Fed. 210, and CCI 200 appear to be about equal. The FM210M is a little milder than any of these, with the R-P 9-1/2 being the mildest of the bunch.