Tejano,
The half inch freebore for the 375 IS the original length developed by Roy Weatherby, since his passing, Weatherby throats have gotten shorter and shorter.
I run all the original throat lengths and use the reamer prints to order reamers. My shortest throat is .375”, perusing the original specs, the 378 and 460 had .750” throats in the early days.
Currently have 270 Weatherby, 300 Weatherby, 340 Weatherby and 375 Weatherby. Have been toying with doing a barrel for my Model 70 switch barrel in 257 Weatherby, just don’t know if it’s worthwhile over my 25-06’s.
It’s the best thing re-chambering my 375 H&H to Weatherby, it’s the whole package that matters, I have not had to trim a single case after 4-5 loadings, it simply doesn’t grow.
Cheers.
