SAAMI Spec for 460 Chamber vs 45 Colt

[Fostereast]

I am trying to find the chamber diameter specs for a S&W 460. I have the SAAMI information for the 45 Colt chamber and am trying to find out if the chamber diameter including allowable tolerance is similar.

 

[k22fan]

.460 S&W chamber specifications are on the SAAMI's web site: SAAMI | Sporting Arms and Ammunition Manufacturers' Institute. Previously their PDF opened for me in Internet Explorer but would not open in Firefox. Tonight it is the opposite. The PDF would not open in Internet Explorer then opened quickly in Firefox. After opening their site click on Info & Specs, then cartridge & chamber drawings, then pistol & revolver then the PDF down loads. .45 Colt is on page 68 in the PDF. .454 Casull is on page 71. .460 S&W is on page 72.

In a nut shell, the .45 Colt's 19th century taper is still in SAAMI chamber specifications so two tenths of an inch forward of the breach or recoil shield .45 Colt chambers are 0.0062" larger than .460 S&W Chambers.

Before carbide dies superseded them the taper was ground into RCBS steel .45 Colt resizing dies. Lacking any taper .45 Colt carbide dies had to size the whole case to a diameter that would hold modern .452" bullets tightly so they leave an ugly step near the base of the case.