Bearman375
Well-Known Member
Gunsmith did it per my request, he's done lots of themWhere did you get that freebore number from?
Freebore on a modern reamer is .376" from Weatherby. This is todays generic freebore length.
Before being put into CIP spec, freebore ran .500" (300, 340, 375) .750" ( 378 ) 1.00" 460. The 416 ran .376 and .750 for a short time.
There were .376 for the 3 short mags, 257, 270 & 7mm. 240 doesn't have freebore.
Cheers.