Hi guys!

I have another question for you. What type of primer should be used with a 180 grain, 300 Win. Mag. load with somewhere around the 75 grain mark powder charge. I have always used Winchester primers, either WLR or WLRM but some of the loads use Fed 215. What do you recommend?

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Canaduck,

I use RL 22 in my 6.5 Gibbs and .300 Winnie. I have found that magnum primers are not particularly consistent in either.

My best groups have been obtained with CCI BR-2 primers in the Gibbs and CCI 200 primers in the .300.

Cheers,
Canuck

I use standard primers on rl22. They normally give me more consistant velocity. The only time I use mag primers is with large case full of very slow powder. I'm sure there are many that have just the opposite experience so you will need to see for yourself.

HI Canaduck

I use CCI BR2 Primers in most of my loads they seem to give me a better group. In the large mag case I use CCI 250 Primers.

I use a Fed 215 for for RL22, when loading 7RM or .300WM. It's worked great for me, but I must admit I haven't bothered to play wiht alot of primers. I usually get a load that works well and stick with it.

Rule of thumb ... If the case is larger than 30-06, use mag primers. I Use the 215M and 75.0 gr of RL22 in my 300 which sends them @ 3100 fps with fully preped and fireformed Win brass and 180 gr Nosler balistic tips in a 1/10 twist RUGER. Best 3 shot group is .22 moa at 300 yards. Some say that the fed match stuff is the same, but they run the machine at 1/2 speed during the manufacturing process. Since the primers are the lowest cost component in the reloading process, why not?

I use the Fed 215 primer in all my magnums from .257 Wby up to .358 STA, except one. The one exception is my old trusty .300 Win and with it I use the Fed 210. If I use the 215 for the .300 I blow my group to 1 to 1.5 inchs as compared to a one hole group with the 210. My powder for the .300 is RL-22. I use nothing but the Federal primers. Good Shooting.

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The Alliant loading manual, and Hercules before them, strongly suggest using standard primers instead of mangnums in their powders unless they recommend otherwise. See footnote #3.

ssleefl's rule of thumb is dead on with the manufacturer's recommendation which recommends magnum primers for all Weatherby's and most larger cases in their loading charts.

Above about a 65g powder capacity you almost have to experiment with the two types of primers. In almost all cases my accuracy has been significantly better with standard primers, even with capacities well over 75g, but you have to try the others. Magnum primers have scattered my groups too.

I've used a fair bit of RL19 & RL22 and have started using some RL25 and I have never found a magnum primer to be more accurate with these powders. I have had very good sucess with the Winchester large rifle primer. That includes cases up to the 340 Wby

Now you guys have done it. Just when I thought I was getting the very best possible groups from my 7STW, you introduce standard primers in place of the Fed 215's which I have always used. One more variable to test in load development and I'll have burned the barrel out and have to start over with a new one.

I use Winchester Large Rifle Primers for Standard Loads wherever possible in a large primer case. I have found them to be pretty consistant, especially with RL-15 in 22-250 or .308.

Most concur that the Winchester primers are a little hotter than their competition so at around 65 grains of powder the standard primers may prove sufficient and uniform. For the big cases I pretty much stick with Minchester magnum primers as they are about the hottest when checked with infrared photography. When loading 106 grains of AA 8700, a hot primer is more of a requirement.

Generally though, unless you have a lot of experience and the ability to measure pressures, it is nver too good an idea to stray too far from published data. It isn't the average that get you, it's the one stray result from inconsistancy of one sot or another that goes over the top that gets you.

The main reason that many powders don't show up for some loads, the occasional inconsistancy that falls outside of acceptable deviations.

Has anyone tried the Federal LR Match Magnum primers? I get great results with my .300 Win Mag using them with IMR 4831.

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Happiness is a 200 yard bughole.

I have never found any advantage of magnum primers over standard primers. Even with extraordinarily slow ball powders like WC 872 in a .264 Magnum, standard primers perform fully as well.

By the same token, you probably won't be at a great disadvantage with magnum primers -- they'll just cost you an extra 2 bucks a thousand.