• Frank's Lesson's Contest

    We want to see your skills! Post a video between now and November 1st showing what you've learned from Frank's lessons and 3 people will be selected to win a free shirt. Good luck everyone!

    Create a channel Learn more
  • Having trouble using the site?

    Contact support

What Primers do you use in your 7WSM, LR or LR MAG

Re: What Primers do you use in your 7WSM, LR or LR MAG

Magnum- because that's how the case was designed. You can use a standard or mag primer in almost any case that takes one or the other. But you will have to compensate for the powder charge to reflect which primer you use.
 
Re: What Primers do you use in your 7WSM, LR or LR MAG

I know you should use mag primers, but in the case of the 7WSM, more people choose LR primers over mag, and I want to know why.
 
Re: What Primers do you use in your 7WSM, LR or LR MAG

Use what works. I have used 210Ms and Wolfs LRM (which people don't consider a magnum primer) with great success.
 
Re: What Primers do you use in your 7WSM, LR or LR MAG

The reason I ask is, I have 2K 215M's that a local Hide member wants to trade for 210M's. I have read quite a few places that its better to use LR primers as they are more consistent than Mag primers.
 
Re: What Primers do you use in your 7WSM, LR or LR MAG

From 6mmbr.com

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">While the WSM case requires a Magnum-sized boltface, it uses a conventional, large rifle-sized primer. (Magnum LR primers offer more spark but they are the same size.) We've heard good results with CCI, Federal, Remington, and Wolf (Russian) large rifle primers--both regular and magnum versions. You may want to experiment with both regular and magnum (extra energy) to see what works best with your choice of powders. Normally CCI is a top choice for shooters running very hot loads. This is because CCIs have harder cups than other brands and can stand higher pressure loads before they crater. This is not a major concern with the 7mm WSM, however. The case has abundant capacity, so you don't have to drive the case at max pressures in order to get 175-180gr bullets to 2950 to 3050 fps--the most accurate velocity range.</div></div>
 
Re: What Primers do you use in your 7WSM, LR or LR MAG

Typically, shooters have reported lower ES and SD numbers with the standard primers. But, you are shooting a mag caliber with a big powder column. When using a standard primer in a mag case in cold temps, it makes it harder to ignite the powder. This can cause hang fires. So, it's up to you. You will lose velocity by switching to a standard primer. To offset this, you need more powder. So, why would you want to use a standard primer in a mag case?
 
Re: What Primers do you use in your 7WSM, LR or LR MAG

Depends on powder too. I shot Ramshot Magnum (a ball powder) in my 7wsm. Since I also used mag primers in a 243 with ball powders of course I was going to use mag primers in a big case like the wsm.
 
Re: What Primers do you use in your 7WSM, LR or LR MAG

I use BR-2's with Magpro in my 25WSM. No problems shooting at 18 degree temps. That's about as cold as it gets around here.
 
Re: What Primers do you use in your 7WSM, LR or LR MAG

I use 215M primers, but am going to test some Wolf LR Magnums (the same primer with a harder cup) this summer to see how they respond.

I shot and pulled targets for a guy using a 7SAUM, Berger 180s, and WOlf LR primers in February when it was 40 degrees; his load sucked and his vertical was out of control - at least for him. We talked and I suggested he try "warming" his ammo in his pocket for 10-15 minutes before the next relay. He did and his vertical went away. I can't and won't say that regular LR primers will not work for a 7WSM or 7SAUM, all I know know is that they didn't work in a 7SAUM with his load in the winter in Las Vegas this year.

JeffVN
 
Re: What Primers do you use in your 7WSM, LR or LR MAG

So what velocity differences would you expect between a magnum and standard large rifle primer?

I'm using Federal 210 match and with a COL of 2.900 and 66.5 gr of RL 25 I'm getting 2915 fps.