I've been reloading for about seven years now, but yesterday I must have had a brain lapse as I mistakenly grabbed the wrong box of primers. I was loading 165 gr Hornady Interbonds in 300 win. mag over 79 grains of RL-22 for use in my Ruger #1. I mistankenly used Federal 210M primers, which are large rifle primers rather than the 215M, magnum large rifle primers.
Before I disassemble the thirty rounds that I loaded I thought I might ask if anyone has had experience with std. large rifle primers in 300 win mag versus magnum lrp's.
Thanks
GWB

Were I you I would try a couple of them at the bench to test for accuracy. A friend of mine and I were doing just that,using std primers and slow powders and found an apperent decrease in pressure as well as an increase in accuracy. Our reasoning was that by starting out the bullet more gently(?) there would be more room for expansion as the bullet started moving while the powder was still burning and less likelyhood of deformation. Course thats only my opinion and there are a whole lot of much smarter guys on this board than me. derf

I don't use "magnum" primers in my .300 Winchester, I use WLR...works just fine.

Thanks for the info guys, it sure helps with the caution and confidence factor. I'll try out these loads soon.

If you'll read footnote #3 in the Alliant reloading manual you'll see they DON'T recommend magnum primers for their propellants EXCEPT where they say so. They recommend standard large rifle primers for the 300 Win Mag. Where they do recommend magnum primers is usually for cartridges with over 80g capacity, like Weatherby's, Rigby's, etc. I use 210M's for virtually everything with Alliant powders and they usually give better accuracy, better SD's and slightly MORE velocity!

I only use Fed. 210 primers, in my .300WM.
No more mag. primers for me with that rifle..sakofan..

Had you worked up a load for std. primers and used magnum by mistake then I think you would be smart to pull the bullets and replace the primers. However the way you did with the cooler one in the case I, also, would give two or three a try without being concerned. Then check the cases over for inappropriate pressure signs.

Good Shooting, "Z"

Once again thanks for the input guys, it is much appreciated!!
GWB

I've seen articles where they somehow tested the "hotness" of primers. The federal 210 is usually about the 3rd hottest primer behind the win mag primer and fed's 215. For some reason it seems the 210 is hotter than other brands "magnum" primer. I'm not sure how they came up with their conclusions but you certainly won't have a problem.

I've tried different primers in all of my rifle cases, magnums & "standard". Every rifle is different. You may find that mag primers give you a bit more accuracy or not. Same goes for using match primers, try diiferent & shoot what works for you. I would only worry about pressure problems if I had a known max, load & substituting ANY primer could cause you a problem.

My standard .300 Win. Mag. powder is Reloader 22, and my standard primer is Federal's 215 or 215M, depending on the rifle, and it has been for the last ten years.

I tried Federal 210M primers with the same powder charge as an experiment and extreme spread readings went from 12 to 105!

I wouldn't take Alliant's standard primers-only recommendation as gospel. You still need to experiment with your own rifle, and you MUST employ a chronograph unless you're willing to settle for potluck.

AD

A few bench rest guys I know use Fed 210s regardless of the Case being a Mag or Not.
One shoots a 338 Lapua using the Federal 210s.

Not personal experience, just passing it on.
I do load Fed 210s in my 300 and 338 Mags, but since I don't shoot them often anymore, I have not looked closely enough to notice any performance problems or deviations. ( However with respect to my fellow Oregonian, Allen Day, I have not bothered chronographing anything)

Thanks again guys for all the input. It is really appreciated.

Allen Day,
I chrono all loads that I shoot. I also consult Nosler, Hornady, Speer and Hogdon reloading manuals before I choose powders to work up loads. I always start below max. However, when the manuals all call for magnum primers, I've never tried a standard large rifle primers. That was the reason for the question.
Thanks all
GWB

I have no experience loading for a 300 Win Mag, but I do load for a 375 H&H, and I now always use the WLR primer (non-magnum) in it. I've never had ignition problems, and the non-magnum primer seems to give me slightly better accuracy than I got with this rifle when I used Federal 215 (magnum) primers in loads for it.

If it were me, I'd shoot the loads you made without any qualm. If anything, the non-magnum primers should give you very slightly lower pressures and velocity than what you should expect to get with a magnum primer.