Savage No1 Mk4* chamber cast results

[brnomauser]

So I’ve just done a “pound cast” on my new-to-me 303. It’s a no4 mk1* with a sportco barrel. The bore is dark, but rifling is pronounced.

Used a resized cartridge with a close fitting bolt cut to depth of cartridge. Pure lead 30 cal bullet, aluminium rod down the barrel and “pounded” for a bit. Took some more pounding to get it out...

Looks like it missed the rifling, even though it was 19mm past the neck. The throat (but before rifling) portion has a slight hexagonal shape, the part of the throat (lacking terminology here) immediately after the neck is pretty round though. It measures 0.342”, the throat before rifling .320” major .312” minor. Inside of a fired ppu case .316”, outside .342”.

Only thing confusing me is the hexagonal throat... otherwise I assume I’m ok to go for a .316” final sized cast bullet? Anyone have any comments

[quasi]

should be called a #4 mk1*

[Der Gebirgsjager]

I'm not familiar with hexagonal throats, or how one would cut one, as chambering/throating reamers are round, and cut round throats. Perhaps your pound cast did not fill out completely, which is why I use Cerro-safe castings. If this is not so, then you'll have to use hexagonal bullets.