I agree that the next best accuracy improvement will be the trigger. But at this point what I want to know is if retrofitting the Target bull barrel with a Green Mountain or a KIDD (as an example) really provides any significant improvement and if it's worth the investment?[quote/]
I think that depends. What do you consider significant for your intended use?
I have a 10/22 with Addams & Bennett/Midway USA(by Green Mountain) 18" heavy barrel in a Fajen Stock, VQ target hammer, extractor and aftermarket bolt buffer. Had a buddy with a stock 10/22T (except extractor & bolt buffer). We never did a barrel swap, but we were both able to consistently shoot smaller groups with my gun in informal testing.
The two guns both had a specific ammo that they preferred. They were set up with the same scopes, rings and bases. They were shot from the same rest set up, same magazines, same bench/lane and same afternoon. We were both able to hold 1/2" or better groups with my gun. With his gun, our groups were right around 3/4"-7/8". We each shot 7 5-round groups with each gun at a paced off 50 yards. Not spectacular by any means, but pretty good for a couple of casual target shooters.
I have a bit more in upgrades in my gun than what he paid his for. For me personally, the investment was worth it.