Hello Oleg
this is in regards to the 10.75x65 r collath.

I found the data on the chmaber cast I had done a few years ago.
base .482"
neck .471"
bore diameter .433"
Their is a slight taper at the neck to accept the bullets when I run my cases throught the reforming die.

I am using 44 caliber hard cast bullets in my reloads.
When I had the chamber cast done I sent the cast to Huntingtons and they made up a set of dies for the chamber. They told me it was a 10.75x65r collath by my chamber cast.
I tried the load in handloaders digest and the amount of powder listed was to little to properly work for the cartridge. I since have slowly worked up to a load I feel is good for the gun.
thanks
ralph