Hi All,

My gunsmith proposed to improved .458 Win Mag in re-chambering my CZ rifle with .416 Rem brass in full lenght (2.83" to 2.85") neck up to use bullet .458. But what is the name of this caliber? What is the closer caliber that you know comparing my gunsmith proposal? Can I continue to fire .458 Win aftre re*chambering? WHat is reload data for this cartridge? Thanks to help me.RGDS. BER007

I propose that if you don't know what you are doing, stay away from it...

The .450 Watts and .450 Ackley are both formed on the full-length .375/.416 brass. The .458 Lott is formed on slightly shortened .375/.416 brass. There are undoubtedly others that are similar.

You need to know exactly which one your gunsmith has in mind, and what the finished dimensions will be. You also need to understand whether the finished product will require custome-made reloading dies or not.

Sounds like a long conversation with the 'smith is in order.

Thanks to ricciardelli and to BigIron.. Your replies were very useful. I'll go with case lenght 2.85" for re-chambering my CZ 550 Safari Mag into .458 Lott. My gunsmith told me there is no probelm with this rifle with maximum lenght case (2.85"). But it is more easier to reform .375 brass than .416 brass. And the difference of maximum powder load isn't so high. I haven't taken final decision of brass used. But what is the reload data for full lenght case (2.85")? RGDS. BER007