I have read about the Duane Weibe XRM magazine box that was available for the Winchester 70 in 375 H&H. Unfortunately, it does not seem to be available anymore. Is there anyway that is currently available to increase the magazine capacity? I read something about changing the magazine spring to one without a hump using Winchester P/N U356420930 Magazine Spring L/A; does that work? It really seems a shame that the XRM stopped being available.