Am I correct in thinking that one could form 6.5x64 mm Brenneke brass by necking down .270 Win brass to 6.5 caliber and trimming them back to 2.54 inches (case length for the 6.5x64mm)? All of the other case dimensions are the same.

Check the dimensions at http://www.clymertool.com. It appears to me you have the right idea. Brenneke has just a touch larger head Dia but that should not be a problem. You might get a little line on the head after firing.

All of the dimensions that I have checked show that the 6.5x64 Brenneke round has the same head diameter (.473 inches) as the 30-06 family of cartridges. Apparently they didn't use the 7x64 Brenneke case (with the slightly smaller head diameter) when designing this round. It looks like the .270 case should work for forming these cases. Thanks for the input.

Dear 9.3,
I just checked my Accuload gizzy and the dimensions you quote are the same there too. I see it`s still just the basic 6.5/270 which, in my book, is a tad safer than the 6.5/06 as the longer neck assures a 6.5/06 will still work safely and not take the chance of getting a 6.5/270 "crimped" into a 6.5/06 cut chamber. I built a 6.5/06 for a Marine Col a long time ago and he used UNTRIMMED 270 cases and got a WHOLE lot of pressure real quick. This is something I always go into with a 6.5/06 customer BEFORE the chamber is cut.

Aloha, Mark

dont mix head and base

head is in 0.473 ( OK on 308 bolt )

base ( dims at 0.2 from bolt face is smaller on 6.5x64 near 0.469 but can confirm by CIP file checking ) so with fresh 270 case that can works but check your chamber base before to make a big batch )

good shooting

DAN TEC