300 wby vanguard copper issues.

bfarms

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milford ky
Long story short. I inherited a 300wby from my grandfather. He said it hurt his shoulder to shoot it anymore after having surgery on it. Anyways it got to where it was a 8 moa gun at 100 yards lol. Checked all obvious. Action screws, scope, mounts etc. never could find anything wrong. The rifle has maybe 150 rounds down it since he bought it new in 92. I found out it was copper fouling. If you cleaned it, it would hold a good 4 shot group then start spitting them again. ( doesn't matter if it's factory or hand loads). Cleaned it again with boretech and ran a borescope down it for the first time. It still had copper smeared in it. So I pulled out the Montana copper killer and finally got it cleaned. Shot it once and ran some patches down it. This is the result from one shot. Is this normal copper deposit after 1 shot? Seems excessive to me and I don't see anything causing it in the bore.
 

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Doesn't look terribly abnormal for the surface finish of the barrel. What size group are you getting for the first 4 shots? Hard to believe copper fouling alone would make a gun go from even 1 moa to 8 moa in short order.

What is the condition of the entire barrel? Could you slug it to see if there is a constricting point? Is it bedded? Any sign in the stock of movement? Did it always shoot that way for your father?
 
Looks rough, but not severe. I would try JB Bore paste or Iosso then shoot it again to see how it groups. Other than that, I would look at what torque you're using to tighten the action screws.

Cheers.

^^^^^^^^^^^ THIS ^^^^^^^^^

I polish the bore on every rifle we purchase……..unless it comes with a match grade barrel. A 22 RF being the only exception to that practice! memtb
 
Factory barrels are not lapped , why is that ? Because it's more time and that equals money. Solution read up and educate yourself on the process,Or call a gunsmith and get a quote from him on lapping the barrel . Barrel steel is hard JB bore paste is Fantastic stuff, the copper is catching on what ? minor barrel imperfections leftover from the barrel's manufacturing processes , what ever they are & many are different . So many people don't properly clean their rifles barrels , Oh that's a waste of time , I don't do that!!!. Then they turn around and Blame the Rifle . Sad really,but it doesn't have to be this way. Pride of ownership includes normal maintenance,a 44 inch cleaning rod,one bore guide ,copper brushes,and cotton flannel patch's , goes a long ways toward keeping your rifle in tip top shape . Great pictures you hold the Solutionin your two hands . Cheers 😉😆
 
I should have stated. I have used jb on it already.
Keep going with it.
Here's my factory 338WM barrel, got the rifle at half price, was a warranty replacement…
Worse than yours.
 

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