Here is the latest on the issue with my 300 WM Bergara. My gunsmith cleaned the barrel to the bare metal with a bore compound. We wanted to find out how fast it fouls with copper. I shot about 16 shots and it has some fouling. The accuracy was very inconsistent. I am using the best load that has produced best groups (77.5 H1000 under a 208 Gr ELD-M). Shooting prone from a bipod and solid rear-bag. 3 fouling shots were two that were near same hole with a third about 3" away. Then I shot a five shot group that was a little over 2." Then 2 more groups that were maybe 1-1/"2 to 1-3/4." At that point, I determined it is going back to the factory. This is hard, because I really need that rifle for an elk hunt. I thought it might be best if someone else shot it before sending it back so that nobody could say it is me. I suspect that the manufacturer will send it back and say it is OK because, sometimes, it has shot a 1" group. Sometimes slightly better. But not consistently (shooting the exact same load from same solid rest). So we took it out and shot it. We are now using a bench rest with sandbags without the bipod. He shot 5 shots in a little over 1." Still not good. But not as bad as my previous groups that day. So then I shot 3 shots from the same bench. They shot a 3/4" group with two nearly in the same hole. I have shot this thing with and without a bipod. It usually shoots better with a bipod. But that is the only difference in shooting today - other than a little copper fouling. The shots I did earlier were with neck-turned brass. The shots later were with stock brass.
So, if I were reading this, I would first guess if the inconsistency is the nut behind the stock. Not saying it is impossible, but I think it is more than that. I don't believe it could be the scope. My load is something I have been very meticulous with including seating depth and neck tension of .002. I don't think it is the barrel either, other than maybe it prefers a certain amount of minor copper fouling, but then accuracy falls apart when it gets a bit too much. The action screws are set at 55 inch pounds. The muzzle break has been reamed to .020 over bore and it is tight. The stock is not supposed to need bedding. It looks like it should not need bedding. But there is a bit of a shiny place where it has rubbed at some point under the action screws. I am all ears for any ideas.
