Chamber specs

[Royzo]

Does anyone have access to chamber specs? I have a rem 700 barrel in 458 win mag imp that I did a chamber cast on today. This imp (improved) stamping has me very curious. Now I need the factory specs to compare too. I have a suspicion of what has been done to the barrel, just need info to confirm before possibly starting a build.
Before anybody asks, I can't contact the gun smith who did the barrel work because it was bought at his estate auction.

 

[joe-boy]

Here's the specs for the 458 Win Mag to compare to your chamber casting ... I haven't found anything for the "improved".

 

[joe-boy]

FYI: for future interest sake, SAAMI cartridge specs can be downloaded from here :

http://saami.org/specifications_and_information/index.cfm

 

[flange]

Maybe try Imperial Magnum something should turn up

 

[Royzo]

Thanks for the info guys.

According to my measurements and the diagrams posted, the improved seems to be that it has been reemed out to take 2.85 length brass instead of the original 2.5.
It must have been done for reloading purposes due to the compressed loads.
What would be the best brass to experiment with?

 

[hunter5425]

The 458 Lott is 2.900" which is close to what you have, could someone have gotten creative in stamping the barrel ?

 

[oneadam12]

Lots of them got reamed to .458 Lott, maybe somebody just went until Lott brass fit?