Hi,
asking for advice,can one convert a 458 Express ("3") to a 460 Weatherby Magnum? The difference between the two case lengths is just over 2mm.

Reamer bolt face and feeding.

Thanks,so there wont be any problem with "too much free-bore"?

Does any one know how many fps one loses with every inch the barrel is shortened when it comes to the 460 wby mag? The reason for my question is because my rifle's barrel is 22" long,not getting 2300fps that I hoped for and that is why I want to convert.

quote:

shortened when it comes to the 460 wby mag

Sorry don't have a clue on that one.

In the for what's worth QL calls max in the 458Express and a 500gr at around 2300+/-. Taking same bullet same barrel pressure adding 35% more powder and you raise the velocity to the 2500+/-.

I would not be concerned about freebore. Not a target rifle.

Thanks Ramrod,
I will be 100% satisfied if I can get 2350fps with a 500gr(now only getting 2180fps) and I don't think I will be able to handle more than that because my rifle only way 4kg.