necking up 300 ultra mag
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RecoilRob
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In a word...no. The shoulder OD is only .525 on the RUM so even if you trim the case to a straight-wall...it's going to be hard to seat a .500 bullet *which mostly measure .510* and then how are you going to headspace it? Guess you COULD make it headspace on the case mouth if you wanted to make such a thing. Even if the case body was big enough to allow such a projectile trying to stretch a .30 neck to .50 would very likely make it thin out too much, and it would be slow going trying to stretch the brass that far. Would likely take an annealing step midway to try to stop the cracking from working it so much...but the remaining neck would be periously thin even if you managed to get it that big.
Making a '50 AE Super' kind of case might be interesting if you could find a suitable projectile that would fit and leave .012" on the case walls. Would be a thumper.
In a word...no. The shoulder OD is only .525 on the RUM so even if you trim the case to a straight-wall...it's going to be hard to seat a .500 bullet *which mostly measure .510* and then how are you going to headspace it? Guess you COULD make it headspace on the case mouth if you wanted to make such a thing. Even if the case body was big enough to allow such a projectile trying to stretch a .30 neck to .50 would very likely make it thin out too much, and it would be slow going trying to stretch the brass that far. Would likely take an annealing step midway to try to stop the cracking from working it so much...but the remaining neck would be periously thin even if you managed to get it that big.
Making a '50 AE Super' kind of case might be interesting if you could find a suitable projectile that would fit and leave .012" on the case walls. Would be a thumper.
Varminterror
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Doesn't work - the RUM's headspace on the shoulder, whereas the Capstick headspaces on the belt. Other 500's in the DG world are all MUCH larger diameter than the RUM's at the shoulder, and most retain a slight body taper to ensure reliable chambering. If you blow out the taper, you run into feeding/chambering risks.
Remember - in a 50cal, you're talking about a .538" starting point - you have to have enough shoulder around a .538" neck to work, which puts you in the .590"+ ballpark. The .505 gibbs is about as little shoulder as a guy could manage - it's a .600" shoulder with a .538" neck - I size my brass to .536" giving a 2thou tension before rolling. Even if you blow out the RUM case to a straightwall body, you're only going to get .550" at the shoulder (and poor chambering reliability), and a .538" neck... Not enough. The 500 Jeffery is a .607" shoulder with the same .538" neck. Even blowing out a .338Lap won't get you there, just not enough diameter. The .458socom is likely one of the shortest shoulders around, with a 22thou shoulder, which would still mean a .582" at the shoulder, and personally, I wouldn't mess with such a short shoulder on a cartridge which could only be practically applicable for DG...
A guy could make a formidable 45cal DG rifle out of the RUM case, I've even heard of it being done a few times. Some accounts claim it matches the .460Wby, some say it falls JUST on the Weatherby's heels. Either way, I've failed to see the advantage of it over a more readily available .458Lott, or even .458wm, both of which keep me plenty happy, as does the .416Rigby for this type of cartridge. The .416Taylor is a wildcat which intrigues me, as it'd give me a flatter trajectory than the 458, while still fitting in a standard long action - although it's hard to justify paying Norma $3 per case for Taylor brass, instead of simply buying more .416 Ruger brass...
Wouldn't touch that idea with a 10ft pole. A 50cal bullet in a case with capacity like the RUM's is going to need a heavy roll crimp, unless you're talking about a single shot rifle.
Remember - in a 50cal, you're talking about a .538" starting point - you have to have enough shoulder around a .538" neck to work, which puts you in the .590"+ ballpark. The .505 gibbs is about as little shoulder as a guy could manage - it's a .600" shoulder with a .538" neck - I size my brass to .536" giving a 2thou tension before rolling. Even if you blow out the RUM case to a straightwall body, you're only going to get .550" at the shoulder (and poor chambering reliability), and a .538" neck... Not enough. The 500 Jeffery is a .607" shoulder with the same .538" neck. Even blowing out a .338Lap won't get you there, just not enough diameter. The .458socom is likely one of the shortest shoulders around, with a 22thou shoulder, which would still mean a .582" at the shoulder, and personally, I wouldn't mess with such a short shoulder on a cartridge which could only be practically applicable for DG...
A guy could make a formidable 45cal DG rifle out of the RUM case, I've even heard of it being done a few times. Some accounts claim it matches the .460Wby, some say it falls JUST on the Weatherby's heels. Either way, I've failed to see the advantage of it over a more readily available .458Lott, or even .458wm, both of which keep me plenty happy, as does the .416Rigby for this type of cartridge. The .416Taylor is a wildcat which intrigues me, as it'd give me a flatter trajectory than the 458, while still fitting in a standard long action - although it's hard to justify paying Norma $3 per case for Taylor brass, instead of simply buying more .416 Ruger brass...
Wouldn't touch that idea with a 10ft pole. A 50cal bullet in a case with capacity like the RUM's is going to need a heavy roll crimp, unless you're talking about a single shot rifle.
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