Originally Posted by o2bwest
I've been shooting a lot in preparation for a hunt. Of the 2 rifles I have been shooting, a 7mm wsm and a 300 wsm, I have noticed that the 7mm seems to build up substantially more copper than the 300. Why is this? Is it a problem? What can I do about it?
The increased copper fouling in your 7 WSM might have different kind of reasons.
The kind of bullets you use. Iíve personally made the experience that some bullets give more fouling to a certain barrel than others. Especially interesting in this case are monos made of copper like the Barnes etc. They have a tendency to give more copper fouling than the usual ones. So change the type of bullet and check the results!
Lighter bullets with higher speed may give more fouling. Coefficient of friction.
Condition of your barrel? New or old? Have you carried out a reasonable break in of your 7 WSM?
A little advice at the end. You should not compare two different rifles with two different calibres due to their characteristics! Thatís like a comparison of apples and pears. I hope youíll get the problem solved soon.