7mm Rem Mag primers

[Cr1775]

Anyone use WLR primers cant find magnum primers using IMR 4350 61 to 63 grs Nosler 150 gr Partition with peterson brass loaded some up got great results. Could there be a issue in cold weather and not work? They are for a friend hate to ruin his hunt. Thank you.

 

[jakelly]

IMR 4350 is great powder. Help him determine his delta/*. Many people consider all win primers magnums. IMR 4350 has never been hard to light. Best guess is, you’re fine.

 

[Steel head]

I use regular LR in my 7 saum with 60ish grains of powder, no issues in the cold at all.

 

[Mr Tibbs]

I would not worry about using the large rifle magnum prime until the bullet weight gets up to 160 Gr‘s and the powder is slower burning,something like the 4831’s and slower

 

[MtnCreek]

I only use Win LRP's for low pressure 6.5 swede. That's after putting three divots in the boltface of a 300wm. Several yrs ago, so maybe not an issue anymore.

 

[AZgeek]

Did a quick test last week with CCI 200's in 7mm Rem Mag using 72.5 gr of WC857. Slow H1000 equivalent. Ten rounds, all went bang. POI shift is likely between a magnum and standard large rifle primer.

 

[918v]

Yeah but will they go bang when it’s freezing? Or will they hang fire?

 

[pell1203]

Yeah but will they go bang when it’s freezing? Or will they hang fire?

Stick some rounds in the freezer or put them in a cooler with a bit of dry ice and then try firing them. Only way to guarantee or prove to yourself they’ll go bang when they are cold.

 

[Criver600]

WLR's are good to go in a magnum

 

[AZgeek]

Yeah but will they go bang when it’s freezing? Or will they hang fire?

Well, I live in AZ so normally cold not an issue for me. Based on my research, cold weather ignition is the main (maybe only) reason magnum primers exist. I'll have a new barrel for my 7mm in about two weeks. I'll chill 10 more to use during the break-in period and see what happens.

 

[MtnCreek]

Ball powder would probably benefit from a hot primer more than h1000.

 

[Mr Tibbs]

Well, I live in AZ so normally cold not an issue for me. Based on my research, cold weather ignition is the main (maybe only) reason magnum primers exist. I'll have a new barrel for my 7mm in about two weeks. I'll chill 10 more to use during the break-in period and see what happens.

Powder burn rate ,volume of powder and temperatures are reasons magnum primers are used .

 

[AZgeek]

WC857 is a ball powder and is slower than H1000. 72.5 gr is a fair amount of powder so for this cartridge temperature appears to be the only unknown with the normal LRP. Would be interesting to know what cartridges and combination of these three variables REQUIRES a magnum primer outside of extreme cold scenario.

 

[Mike Casselton]

I still have a 1k sleeve of Winchester primers that are listed as WLR.
The info on the box says: "For standard or magnum loads."
They worked just fine in 7 Mag, 300 Win Mag, 338 Win Mag and 375 H&H while living in South Dakota.
We shot all year including below zero temps.
The primers were perfectly fine, even with H-870 powder.

 

[918v]

But current WLR primers are different. There’s WLR and WLRM. I wouldn’t use WLR with ball in a magnum.