Originally Posted by Nitroexpress
gerryb ~ whats your free bore on your 375 RUM please????
This is my 7mm RUM
~ a work in progress (finding my favorite load that is) ~ I think there is too much freebore (200tho if I seat in the case as little as I dare)
My smith says I should'nt be loading ultra mags really close to the lands anyhow but ive had issues (sooting the full length of the case)
I ve gone to a faster powder and its far better but it hasn't loaded as easy as anything else ive done (and ive done a fair bit over the years .222, .243, 6.5x55, .300wm, 9.3x62, .416rm & .470ne with no issue)
Example of the case condition.
Going off topic a bit
- but useful advice very welcomed!
Hang around on this site long enough and you will see something new.
I have been loading for over 50 years and I have never seen this much soot.
Give us your loading procedure and loads and maybe we can help you.
Normal soot is confined to the neck because the case seals it,s self off before it get beyond
All I have is questions at this point.
Are you full length sizing?
What primers are you using?
What powder are you using?
What is your neck to chamber clearance with a loaded round.
What is your head space?
Your smith is right about the free bore. The RUM,s and the WSM,s along other High pressure
cartriges need free bore to keep the pressure down and the velocity up.
Most of the Weatherbys have more than .300 thousandths free bore and if you reduce this
very much you will not be able to shoot factory loads and you will give up velocity.
The problem as I see it is that the case is not expanding enough at initial firing to expand the
case, sealing it off in the chamber.
Please keep us posted on this problem because we can all learn something new.
J E CUSTOM