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"Improved" belted mags

Alan RushingAlan Rushing Member Posts: 8,805 ✭✭✭
Do you know of folks that have created "improve" ( 35-40 degree) shoulders on any of the belted magnums, other than the 300 H&H ?

I realize that with the 300 H&H it would create a completely different animal, with significant change of performance and other characteristics.

How about with the 7mm Rem Mag, what if any positive characteristics might one anticipate if any at all? It would seem the case changes would be an "improvement" with case capacity and directing the plasma, etc.

It would seem that the life of the brass would be improved as with many other cartridges.

Has anyone direct knowledge, self or a buddy, that has worked on this? What changes were discovered or observed?

Your thoughts?

Comments

  • nononsensenononsense Member Posts: 10,928 ✭✭✭✭
    edited November -1
    Many if not all of the belted magnums have been through the 'improvement' process over the years. Wildcatters are an aggressive group of knowledge seekers and something as little as changing a shoulder angle won't stop most of them.

    The Weatherby cases are an improvement of sorts with the venturi design especially when compared to the standard 25 degree shoulders found so predominantly on American belted magnums. Probably the most significant change in shoulder angle is with the 7x61 S&H Super with a shoulder that is 44 degrees. But here the body taper is significantly more than usually found with our American counterparts. The shoulder diameter is 0.473" as opposed to the more frequently found 0.490" or similar.

    Brass life is usually extended by minimum resizing on the belted magnums. Headspace is controlled by the belt but case stretching is controlled by not pushing the shoulder back but letting it be a part of the contact in the chamber. If the case touches on the front of the belt and the shoulder, the case can't stretch and suffer from head separation.

    Several other belted cases have been improved including the .300 Weatherby where the shoulder has been changed from the double radius to the standard shoulder except at the improved angle.

    There limits to these improvements just as your other thread might suggest. There is the necessity of minimum body taper to aid in extraction.

    Best.
  • n/an/a Member Posts: 168,427
    edited November -1
    I have a .300 Win Mag A.I. I'm working up loads for it now.
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