Thought some might find this interesting or helpful. I have a adams bennett barrel for a savage model 11 I bought from midway a few years ago. It wasn't very accurate bout 1 1/2 groups best I could which is Ok since was for thick woods hunting and it only cost 69 dollars.
I had taken the barrel off and was using at Winchester model 70 featherweight in 270 as a all around rifle. I decided to see if I could get the cheap barrel to shoot better, so I put it back in savage receiver then took a 1 inch id thick wall steel pipe and put it on the barrel. I made two bushings out of hot water plastic pipe, one midway another at muzzle. I beveled inside if pipe so it fit on barrel nut, then had it welded.
The results were great the 139 hornady spbt that were 1 1/2 groups became 1/2-3/4 groups. And 162 amax that were 2 inch are now 1/2 an inch. 168 sierra gameking are even better. Here's a 12 shot group at 600 yards the two out of circle were before scope adjustment. It's the circle on the right. The circles are about 8 inches in diameter.
I had taken the barrel off and was using at Winchester model 70 featherweight in 270 as a all around rifle. I decided to see if I could get the cheap barrel to shoot better, so I put it back in savage receiver then took a 1 inch id thick wall steel pipe and put it on the barrel. I made two bushings out of hot water plastic pipe, one midway another at muzzle. I beveled inside if pipe so it fit on barrel nut, then had it welded.
The results were great the 139 hornady spbt that were 1 1/2 groups became 1/2-3/4 groups. And 162 amax that were 2 inch are now 1/2 an inch. 168 sierra gameking are even better. Here's a 12 shot group at 600 yards the two out of circle were before scope adjustment. It's the circle on the right. The circles are about 8 inches in diameter.
Turned out to be one of my better bug hole makers. 
Did you glue the bushings in place? Maybe you could fill the pipe with epoxy and really make it stiff.
