I accidentially used WLRMs instead of WLRs in a .243 load. The load is 1.5 g below max in the Nosler Reloading Handbook. I caught my mistake but only after I had completely finished reloading. I am using 100g Nosler Partitions, IMR 4350 powder and Winchester brass. Am I safe or should I pull the bullets and start over?? Please Help!!! Ray

You didn't say how many you have loaded but the chances are high that you'll have no trouble at all with the mag primer.

Here's what to do; remove a bullet from one round and then also remove three more grains of powder and fire it. By doing this you can work your way back to the loads you have and prove that the load is OK.

I don't know where it was, but somewhere in the dim past I remember instructions to lower max powder charge by one grain if substituting a mag primer for a regular. I would think that if you are 1-1/2 grains below you should be okay, but would second what duikerman suggested, just to be sure.

I use a loading manual as a guide but determine what is safe in my gun personally. I know which loads I could push more and those I shouldn't push more. If my load is conservative, I would see no danger in substituting magnum for regular primers.

I frequently check loads with both large rifle and large rifle magnum primers (and do similar tests in handgun cartridges). The only time I've seen higher pressure result was with some 44 Magnum loads I was testing. Frequently there is no difference in accuracy either. A 357 Herrett I load for gets better accuracy (with no excess pressure) with a full load of IMR 4227 and large rifle magnum primers.

A primer is supposed to ignite all of the powder and they can't burn any more than all of it. Both a large rifle and a large rifle magnum primer will burn all the powder and no more. That means that the only ways excess pressure will result is from faster burning of the powder or from added combustable materials from the primer (which would be minimal).

Not all primers are created equal. I know from actual experience that the Federal 215M is one of the hottest primers made and in some cartridges is the equivilent of 1 to 1 1/2 grains of powder. I have not noticed the same thing with CCI or Winchester Magnum primers, with slow burning powders.

If you are actually 1 1/2 grains below max in your rifle you should be OK. Shoot a few and look for pressure signs or chronograph and look for increased velocity. Or save them for cold weather shooting.

Ray

If it was me I'd load a couple back up with the reg primers and go to the range with the chrono. I'll be surprised if you have more than 50 fps difference....and it's even possible that the mag primers could be slower.
I would not be afraid to shoot them myself.

Pull em! A little time is worth a lot of peace of mind....................DJ

Don't sweat it. The WLR is already a relatively forceful primer. The WLRM has very little, if any, additional briscience. You will likely find no difference at all.

In the future, once you've used up all of your WLRMs, simplify you life and buy only WLRs. There is no sporting cartridge or powder combination for which they give inadequate ignition.

Hello the Campfire:
I too vote to go ahead and use the Mag primers, but only for huntung where you have some room for inconsistant loads. By that I mean that the Mags and non-Mags might print differently at the range. Hunting yu will never be able to tell.
Judge Sharpe