Superformance powder data for 7mm mag

[shikaree]

Anyone have reloading data for 7mm mag with this powder.

I have 168gr berger bullets and winter is long so I can do some loading and testing with your help. Thanks

 

[kman300]

I bought some 139 gmx superformance and chronographed it in cold weather. It was 120fps slower than the box said so I call BS on their temp stability claim. Not sure if that is what you are looking for (temp stable) but I have much better success with retumbo and h1000 in this regard.

 

[Underthegun]

I bought some 139 gmx superformance and chronographed it in cold weather. It was 120fps slower than the box said so I call BS on their temp stability claim. Not sure if that is what you are looking for (temp stable) but I have much better success with retumbo and h1000 in this regard.

What did it chronograph in the warm weather?

 

[hometownhero]

I bought some 139 gmx superformance and chronographed it in cold weather. It was 120fps slower than the box said so I call BS on their temp stability claim. Not sure if that is what you are looking for (temp stable) but I have much better success with retumbo and h1000 in this regard.

Only 120 fps less thats not bad the 223 stuff chrony'd at just over 3200(200fps less then they rate it at). I think it was right around -4 that day as well

 

[Andy]

Anyone have reloading data for 7mm mag with this powder.

I have 168gr berger bullets and winter is long so I can do some loading and testing with your help. Thanks

I have done work with it in the 7X57, and found it to be just a bit slower than H4350, and published loads for the 280 Rem show the same thing. Load three each with H4350, Superformance, and H4831 at 58.0 grs and compare their MV's - I expect you'll see their average MV's go down in that order.

I'd then work up loads with it in the 56.0 to 60.0 grain range. I have never found magnum primers necessary with ball powders like Superformance, so I'd start with standard primers.