Bighammer,

I have never had any trouble but they have been, lets us say, rough 4 wheel drives.

You can however get brakes that only blow out the side.

http://www.nearmfg.com/products.htm

Scroll down. These people make good gear and because they are in Canada no export licence is needed.

I have aso used the KDF style brake across an ordinary car bonnet but I have had a blanket on the bonnet and virtually had a bench rest set up on the bonnet.

As Richard has mentioned CZ USA are doing 450 Rigbys. I think you will need to bring those in yourself because Winchester I think would only be dealing with CZ and these are CZ USA rifles. But that won't allow you to have matching Rugers so I would speak to De Vries about rechambering and feeding issues on the Ruger 458 Lott as a first port of call. Also, I am not sure but I think the CZ USA 450 Rigby is quite a light barrel

Let me offer if I may, some advice learned from hard experience. Try and get what you want and avoid being diverted by matters of convenience and within reason, matters of cost.

Mike