I am attempting to diagnose a sudden loss of accuracy in one of my custom rifles. I have an Aoudad hunt coming up this Sunday and am in dire need to get it back shooting properly. The rifle went from 1/2 MOA to 2MOA in the span of 1 shooting session. The rifle is a 300WM with Proof Carbon barrel. It has 546 rounds now and went bad right at 500. I have cleaned the rifling during this period with no improvement. I have eliminated the scope and rings by trying a proven optic from a different set up and still have issues. The ammo is hand loaded so nothing has changed on that front. I have been researching the elusive carbon ring and this is what I see through the bore scope. Do you think this could be causing my issues? I have not seen any noticeable pressure signs. Any other ideas that I can quickly try? Let me know what you see.
Accuracy Loss
- Thread starter aghunter
- Start date
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How often do you clean?
I would say 5-7 times in total after break in but have never examined or cleaned the chamber until now.
Jim’s Hunt
Well-Known Member
It looks like the rifling is washing out and the lower part of pic is showing cracks so it looks to me you have shot when barrel was very hot and with hot loads
Jim’s Hunt
Well-Known Member
What are you cleaning with ie chemicals used type of brushes
Jim’s Hunt
Well-Known Member
Me again check you action screws for tightness. What kind of stock is the action in will determine amount of torque on screws
How many rounds total
C4 Boretech w/ nylon brush and patches
I'm gonna suggest putting some rounds down range and see if some fouling is in order
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Hugnot
Well-Known Member
As simply stated by OP, only 546 rounds & normal wear. I would look first at the ammo, especially bullet run-out, neck tension, case length, & head-space (hopefully at shoulder). Inspect bullets looking for any abnormalities. I think the "carbon ring" stuff is sort of overblown to sell more solvents & cleaning stuff but give it a good overnight soak with some solvent or use some JB. Re check action screw tension (front real tight & others not so tight) & look for bedding issues like stock warping affecting free-floating barrel. The .300WM is a real barrel eater but @ only 546 rounds it should have much life remaining.
I have a 300WSM in a Browning A Bolt that started shooting horribly. I had switched to some factory ammo that I had never used before and thought that was the problem. It wasn't, it was the action screws and was an easy fix.
Jim’s Hunt
Well-Known Member
Some IOSSO or JB bore paste Barnes CR 10 torque screws to 20 inch pounds starting with front then torque front to 35-45 inch pounds
cjuve
Well-Known Member
Check your velocity to make sure that you are still in the node. The fire cracking in your throat looks fairly mild but in conjunction with the carbon ring could be affecting pressure. 30 FPS could be enough to get you a significant increase in vertical.
