Modification of sizing die

BurnOut

DDOJSIOC
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Nov 24, 2013
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In a fit of brilliance/moment of stupidity I have decided that I want to re-chamber a Ruger American Ranch rifle in .450 Bushmaster to 45 Raptor. Since it has been brought to my attention that the 450 BM case has a bit of taper to it that is not shared by the Raptor, I'm thinking that in regard to loading, I won't want to use 460 S&W dies, but instead a set of 450 BM dies that have been modified to allow for the longer Raptor case. The question I have is in regard to getting the sizing die "chambered" to match the rifle.

Understanding that barrel steel and sizing die steel are two very different things, would it be possible/feasible to have the die reamed to the larger (by .002") diameter (at the case mouth) and longer (by .100") dimension using the same reamer as would be used for the barrel? Or via some other method?

Obviously, the end result would be a hybrid cartridge case (45 BushRaptor? 450 Bushmaster Magnum? I dunno.) with the case taper of the 450 BM and the length of the Raptor, but I don't see anything wrong with that. In theory, the rifle would even be capable of firing virgin 450 BM (using the case taper to set headspace), virgin 45 Raptor (using the case mouth to set headspace), and (obviously) fireformed hybrid cases.
 

Dobbs02si

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Jan 24, 2020
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It will take carbide to recut most dies. Like perviously stated the reamer also needs to be undersized. A chamber reamer MIGHT be just enough to bump the shoulder, but it would do nothing to the neck.
 

BurnOut

DDOJSIOC
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Good feedback folks, thanks. What I think I'm reading is that if I want to modify the 450 BM die to allow for FL resizing in this particular rifle, I'll want to use a .476" carbide reamer to just slightly lengthen the depth of it. Yes?