7 mag or is PRC actually better?

[FredH]

It turns out 60 years of cartridge development lends itself to more efficient and inherently more accurate cartridges.

I like my 7mm Rem mag but the 7mm PRC is better across the board except for the current number of rifles and commercially loaded cartridge options available. The belt on the 7mm Rem mag is a vestigial tail and an unnecessary stress riser.

I’m hunting this fall with a 7mm Rem mag but as soon as the barrel is shot out I’ll be rebarreling to 7mm PRC.

How does the belt rise stress? The 7MM RM has been used very successfully as a match cartridge.

 

[xsn10s]

The new Remarms 700 7mm RM comes with 1-8" twist 5R barrel. I stuffed my ADL into a KRG Bravo and haven't even finished load development. Paper is 3 shot 100 yards. Steel is at 550 yards. 180gr ELDM.

 

[Kurts86]

How does the belt rise stress? The 7MM RM has been used very successfully as a match cartridge.

Because when you step down out of the belt to the main body of the case you get a sharp corner with a tiny radius. Sharp corners concentrate stress. Having reloaded 7mm mag that is where the cases often fail.

 

[FredH]

Because when you step down out of the belt to the main body of the case you get a sharp corner with a tiny radius. Sharp corners concentrate stress. Having reloaded 7mm mag that is where the cases often fail.

You could also say the belt itself making the head of the case wider makes for a stronger case head. I have never had a belted case fail at that point. Way more likely to have cracks develop in the neck after many firings. That said I turned the belts off of some 300 Win mag cases I used for a long range match rifle and they lasted the life of the barrel, no issues and no noticeable improvement.