Home Forums Hunting & Shooting Ask The Gunwriters 30-06 inherent accuracy

I did two chamber casts so far now, then I got side tracked. I did find the chamber cast, and the notes I made back when it was freshly done (Cerrosafe castings need to be measured one hour after popping out of the chamber), of the M1903A1 Service rifle so thank goodness I didn't have to do a third casting today. The throat in a 1930 National Match (Star Gauged barrel) mics at .309 with the rifling starting slightly closer to the end of the chamber neck than in the 1903A1 service rifle close to it in age, which also has a .309" throat. (Although the bores are bright and crisp and they shoot sweetly I can't swear to how heavily they've been used, obviously.) Strangely enough the throat in a 1929-vintage NRA Sporter (Star Gauge barrel also*) mics .3085" and the rifling leade is the same as the Service rifle.**


* Star Gauge doesn't make a barrel special in terms of construction. It merely means that it conforms within tolerances for the .30 Springfield barrels. During production, all barrels were gauged with the device and only those that met requirements perfectly were given the Star Gauge stamp of approval on the barrel crown. Legend has it that a healthy percentage of all barrels met the standards anyway.

** NRA Sporters were intended to be hunting rifles so maybe that explains it. Although, I've read where Sporters were popular as target rifles back then too. I don't know, I wasn't there. Ask Pappy348, I think he was there.