325 wsm not shooting well

[cragboy]

I have a winchester coyote brown laminated stock in a 325 wsm. I bought it brannew. I bought a set of forster benchrest dies for it. I bought new winchester brass for it. I loaded some 200gr nosler accubonds behind 68gr of ramshot hunter powder and cci 250 primers. The gun shot great for what I wanted. I was printing 1" groups at 100yds and speed was 2950fps. Then I bought some privi bullets from grafs and sons. I loaded the up with rl 17 and cci primes. I went to the range and grouped them. The shot decent at 100yds 1-1/4 groups from cheap bullets. I shot 3 groups of three shots just fine. I let by barrel cool down between each group. When I started to shoot my fourth group It opened way up to a 3" group. So I let the gun cool completely down. I shot my fifth group and it was about a 4" group. This got me concerned. So I let the gun cool again. So I pulled out the nosler which I Knew would shoot. I shot one more group. This time a 3" group. I was fed up so I took the gun home. I completely cleaned it and took it out of the stock to see if any thing and got in between the stock and barrel. Nothing had. So a week later I took it back to the range. I shot two group with noslers still a 3" group. So I thought my scope was off or the bases were loose. I took it back home and pulled the scope. I checked the bases to make sure they were tight. Every thing was good. So I put it back together and took it back to the range. Still a 3 to 4" groups. I was thinking my scope was not holding zero. I had a Burris on it. So I swapped it with a Leopold vxii 4x12x50. I took it back to the range and shot it again. Still same thing. 3 to 4"groups. I did not know what to do so I asked a friend and he said to change bases and rings. So I ordered some warren rings and bases. While waiting I loaded some more noslers 200gr accubonds. I seated some .010 to .075 from the lands. I got the rings and bases and installed them. Took the gun back to the range Still 4" groups. I took the scope off the gun and put it back on the one it was on. Sighted it in and printed 3/4" groups with it. So I knew the scope was good. Now I don't know were to go from here. Any suggestions. Thanks.

 

[ar15topgun]

time for a borescope inspection. Your clean barrel may not be clean or there may be something wrong with the barrel.

 

[bozo699]

cragboy,
Welcome to the forum, What 15topgun said a bore scope would be in order and I imagine what you will find is a large carbon deposit jut past your case neck on into the barrel a ways, your going to need to get that carbon out! best of luck.
Wayne.

 

[dragman]

bore scope all the way. something is up I had a new savage that did that, It would shoot good and then get worse as I shot. it was copper fouling really bad! after some serious cleaning and some hand lapping it settled right down and stayed good.

 

[cragboy]

Thanks for your suggestions. I appreciate it. Now I will try to find someone in northern Utah who bore scopes.

 

[bozo699]

Thanks for your suggestions. I appreciate it. Now I will try to find someone in northern Utah who bore scopes.

cragboy,
Good idea but if you can't, clean the gun as normal, until patches are light gray or clean then carefully brush the throat area or clean throat area with JB bore paste and see if the patches start coming black again, my guess is you will, my guess is with the story you told you have carbon built up or copper fouled but I would have thought you would have seen that with a normal cleaning, best of luck.
Wayne.

 

[ar15topgun]

Using JB bore paste will black the patches even in a clean barrel. Polishing compound + metal = black residue on patches. Find a gunsmith that has a borescope.

 

[bozo699]

Using JB bore paste will black the patches even in a clean barrel. Polishing compound + metal = black residue on patches. Find a gunsmith that has a borescope.

True that's why I first suggested a brush but you can tell if your getting carbon when using JB paste, I have agreed from the beginning with a bore scope, the nearest borescope from my house is 200 miles so sometime we work blind and figure things out the old fashion way.
Wayne.

 

[cragboy]

Thanks guys. I found someone with a bore scope not far from me. I am going to take it to them next week. I also ordered some JB paste and it will be here in a week. Thanks again and I will post when I bore scope it.