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barnbwt · October 31, 2012, 10:14 PM

Is there an established way gunmakers design magazines/feed systems to ensure the design should function properly? I hear of folks with "buggy mags" tweaking feed lips, honing ramps, reshaping mag catches and all sorts of other stuff. Is there a formula to the madness, or is a brute force guess-and-check the only way to approach the problem?

I'm contemplating converting a Steyr M95 from 8x56R to 45/70, which would require more than just rebarrelling for a repeating rifle. Other conversions attempt to use the existing feed system with similar-enough cartridges (7.62x54R and 30-40 most common). The en bloc clips used to feed the action would need to be substantially modified for the wider, shorter 45/70 round, and are themselves not very durable (disposable, even) in any case. Even successful conversions require frequent readjusting of the feed lips in the flimsy clips.

Since 45-70 would require major clip surgery anyway, I thought it may be better to replace the innards of the entire magwell with something purpose built for the new cartridge, that would hold together much longer. That said, I have no idea where to start. If some guidelines exist for how a cartridge needs to be angled relative to the breech face, how high on the bolt face, etc. I may be able to put something together that would suffice. At least be a closer shot to a working solution, and a much more durable starting point than 100yo sheet metal disposable clips

. The dream is a hi-cap using a modified Madsen or Bren mag, but I'd be equally pleased with a 4-5 shot

Thanks for the expert advice,
TCB

October 31, 2012, 10:14 PM	#1
barnbwt Senior Member Join Date: May 17, 2012 Posts: 1,085	What Makes for a Good Magazine? Is there an established way gunmakers design magazines/feed systems to ensure the design should function properly? I hear of folks with "buggy mags" tweaking feed lips, honing ramps, reshaping mag catches and all sorts of other stuff. Is there a formula to the madness, or is a brute force guess-and-check the only way to approach the problem? I'm contemplating converting a Steyr M95 from 8x56R to 45/70, which would require more than just rebarrelling for a repeating rifle. Other conversions attempt to use the existing feed system with similar-enough cartridges (7.62x54R and 30-40 most common). The en bloc clips used to feed the action would need to be substantially modified for the wider, shorter 45/70 round, and are themselves not very durable (disposable, even) in any case. Even successful conversions require frequent readjusting of the feed lips in the flimsy clips. Since 45-70 would require major clip surgery anyway, I thought it may be better to replace the innards of the entire magwell with something purpose built for the new cartridge, that would hold together much longer. That said, I have no idea where to start. If some guidelines exist for how a cartridge needs to be angled relative to the breech face, how high on the bolt face, etc. I may be able to put something together that would suffice. At least be a closer shot to a working solution, and a much more durable starting point than 100yo sheet metal disposable clips . The dream is a hi-cap using a modified Madsen or Bren mag, but I'd be equally pleased with a 4-5 shot Thanks for the expert advice, TCB __________________ "I don't believe that the men of the distant past were any wiser than we are today. But it does seem that their science and technology were able to accomplish much grander things." -- Alex Rosewater