magnum primers?

talldrink

Beginner
Nov 3, 2006
16
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Loading for a 270WSM as well as a 300 Win Mag. My velocity spread from high to low average about 50-60 FPS. I am using CCI bench rest primers, uniforming the primer pockets and trim all to same length. The cases are also wieghed. A friend of mine told me that I should switch to a magnum primer and this would help me to obtain a more uniformed spread of velocity. If I switch do I need to cut back a powder charge?
 
Just for grins, I load my 270WSM using 140ABs, 61.5gn RL-19, Fed GM215M primers, and a COL of 2.875". This is a fantastic load from my Win Mod 70 Super Shadow.

I also use them in my 338WM and 300RUM.
 
I am a big fan of CCI BR-2's & 4's
With that said, personally I'd switch to the Magnum Primers in the 300.
I have a .300RUM and initially loaded it with CCI-BR's. This is not enough primer to light that load as I experienced a severe hang type fire. The Federal Mag primers resolved that issue in a heartbeat.
Not sure what type of validity it has, but snapping off empty cases that I had primed with CCI's and then comparing to one Fed215, yes, noticible difference in tone / sound / loudness... appears to be much more to the magnum units.
And yes, if at max back off, and work up !
 
I agree with the other posters, you should definitely switch to a magnum primer in those calibers. And yes, you should reduce the powder charge to start. You may well wind up back where you are now, but you need to drop down to start out.

I personally use nothing but the Fed 215M primer in all my magnums. This is a hot primer which serves to ignite large powder charges well, but it is also a match primer that gives consistant results.

In some guns I can tell no difference in the Fed 215M and the regular Fed 215. In others it makes a big difference. I did a pretty good study on my 7mm Wby Mag and tested three different loads with both primers. When all was said and done the 215M primer gave 20% smaller groups than the standard 215.

So try the Fed 215M and have the best of both worlds, a hot primer and a match primer at the same time.
 
Thanks for all the help. I figure cutting the loads back about 10% or should I drop down more?
 
I'm kind of the contrarian on this. What powder are you using? I have found that accuracy is usually better w/ std. primers unless I am using slow or ball powders. Your 300mag may do better w/ mag primers but your 270wsm isn't really buring that much powder. I routinly use Fed. 210M in my 7remmag & find accuracy better than the 215M.
 
fredj338":1rbwh7pu said:
I'm kind of the contrarian on this. What powder are you using? I have found that accuracy is usually better w/ std. primers unless I am using slow or ball powders. Your 300mag may do better w/ mag primers but your 270wsm isn't really buring that much powder. I routinly use Fed. 210M in my 7remmag & find accuracy better than the 215M.

I don't know how 210M will perform as I've never tried them in my 270WSM. Started with WLRM and then switched. Got outstanding results with the 215M, so why try 210M. If you still working a load, that's just one more option to try. I would still stay with mag type primers for your 300WM.
 
I am using CCI bench rest primers. Har dto find the federal primers here. As for powder I am using IMR 4350 in my 270 WSM and IMR 7828 in the 300 Win Mag. Not at home right now so I can't give you the charges I am using but both are just a little over medium in the Sierra manuel. I bought some Federal 215M and going to load a few up to try this weekend. Accuracy in both is fine with the reg primers at 100 and 200 yards, it is at 300 and beyond that I start to get vertical strings. Thinking it is because of the variance in velocity, one load say at 2950 FPS and the other at 3010FPS causing the vertical strings. Just trying to get more consistent loads for long range practice.
 
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