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I've done some reading and found that because the 7mm rem mag is a belted mag case life is only 2 or 3 firings because of a bulge that you get in front of the belt.Is this a true fact or do the newer dies take care of this problem.I'm going to start to reload this cartridge and would like as much info as possible.Would you guys recommend neck sizing or full length for this round. Loads have been and will be fired in the same bolt action rifle.Any advice much appreciated.
I shoot three belted cartridges - a .264 WM, a 300 WM, and a .375 H&H. I have reloaded them for years, and case life is no different than normal cartridges.
I think the stuff you read was put out by a guy that was selling a "special die" that he designed to solve a non existent problem (he is out of business now).
There is no difference between shooting a belted cartridge and a standard cartridge.
There is no "bulge" in front of the belt on a fired case.
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I don't think you need to worry about that problem because the 7mm Rem mag has a pronounced shoulder angle. This allows you to full length size normally.
You do NOT FL rifle cases unless they need it because they are tight - unnecessary FL sizing will cause case head separations.
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Belts started to appear on magnum cartridges because they were not considered magnum unless they had a belt.
That is not true.
The first belted cases were the English cartridges for the African cartridges that were designed to be used in turn bolt rifles. They were designed to replace the rimmed flanged cartridges (like the ".450-500 Flanged Express") that were used in the African double barreled rifles that were popular at the time, but extremely expensive.
The purpose of the belt was to head space the case that was a straight cylinder, or almost a straight cylinder, which had the large bullets heavily crimped in place - so the case could not headspace on the mouth like a 45 Auto, and the turn bolt claw was not able to maintain headspace - so the belt was devised, and it worked very well.
It wasn't until much later that these cases were necked down. The 300 H&H Magnum started out life as a .450 cal belted express cartridge... it then went down to a .375, and a 300, and a .244.... in many variations.
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One example where the belt is actually needed is the 300H&H, which has a long sloping shoulder which can cause headspace problems.
The 300 H&H head spaces on the shoulder on the SECOND shot, like ALL reloaded, bottle necked belted magnums.
There are many cartridges that have long sloping shoulders, or almost no shoulder at all - they all do quite well in the headspace department.
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