Home Forums Hunting & Shooting Express Rifles and Big Bores Only 450 G&A Short

I reckon the .450 G&A Short Magnum (2.5" case) is simply a .460 G&A that is shortened in case body, below the shoulder, by 0.300".
Same neck and shoulder.
Could do it with same reamer inserted 0.3" shorter than the .460 G&A, using appropriate headspace gage.
Just make sure the .450 G&A Short Mag dies resize the brass to match the chamber.
However if you rechamber a .458 WinMag with a .450 G&A reamer, you might as well give it a .458 WinMag throat.
It is going to have one anyway unless you cut the barrel threads and set it back.
With a virgin barrel, you can have any throat you want.
I would want the .458 WinMag throat, then I could do practically anything with it that the short-throated .460 G&A could do.
Almost as good as the .458 WinMag loaded to 3.600" COL,
which can absolutely beat a SAAMI .458 Lott.

All I have is boiled down into the images below.
First from the 1983 BIG BORE book from G&A by Jack Lott:







The two .460 G&A reamers here are identical except the Manson reamer has a slightly shorter and narrower parallel-sided-free-bore,
and a more gradual leade: 0.459" diam., 0.150" long PSFB, 1.5-degree leade hemi-angle.
Clymer throat: 0.460" diam., 0.200" long PSFB, 2.5-degree leade hemi-angle.