Was thinking one the cheapest and maybe best way to get into the 1/2 inch crowd is to rebore a 450 Rigby up to .500"

This case can be necked up to 510 for the 500-450 Rigby (Boom Stick TM) for 15 thou shoulders but this is about the .500" version with 20 thou shoulders.

450 Rigby rifles from CZ are not cheap but would be designed to feed already. 416 Rigby rifles are much cheaper to start with though.

Seems it would give 20 thou shoulders like the Rip's 500 Mbogo but shoot the wide variety of .500" bullets. A much cheaper to shoot slightly downsized 505 Gibs. Even swage down 505 softs as well as all those way cool .500 bullets Michael458 uses.

Neck up 450 Rigby brass is a easy way to form brass.

Things that make you think...

it would be better in my 49 caliber .. .498groovex.490bore .. draw (not swage, that makes bigger) down .500 bullets, and in no way is it a 50

Sorry, draw down.
Yes in either .500" or the soon to be 490 .498"
One thing that makes me like this idea is the ease of forming cases not to mention
Relatively cheap brass and not the 4 or 5$ a piece brass.
Ease of feeding
Ease and low cost of conversion
Cheap bullets
Nominal 505 Gibs performance capability.

The cost per shot could be quite cheap with 50 cent bullets and good strong brass.

The 450 Rigby is a new cart (1995) with wider shoulders than the original 416 Rigby so this cart could be a cousin cart near in age.