Ian and I were making our way our way along the Karamea river after stopping for a billy of tea at the Crow hut. As we finished our brew and lunch it started to rain, not the west coast frog drowning downpour , just a steady rain. About a half hour downstream we stopped to have a cast in a nice looking pool. Rewarded with a good  trout. I noticed Ian fiddling with his rifle. He asked how much water in a rifle barrel does it take to cause a ring bulge. I had to say I don’t know. Looking through the bore on his rifle I could see obvious drops of water most of the way down. I had to say if it were my rifle I would not fire it until we could wipe it out. There was no prospect of doing that till we got to Karamea bend hut. We continued on our way and sure enough there were two deer clattering up our side of the river. We could only watch them as they wandered off. I didn’t take my rifle that day. 

Owen, a long time friend, brought his rifle in for me to have a look at because he said it wasn’t shooting well. Did all the normal checks, nothing obviously wrong. Had a careful look down the barrel. Immediately back from the muzzle there was a bulge, difficult to see at first but the more you looked the more obvious it was. Our smith docked a couple of inches off the barrel and his trusty rifle shot fine again. Another barrel I examined had an obstruction bulge near the muzzle at the rear of the unfluted section. The barrel had then split neatly down one of the flutes the full length of the barrel till the split stopped at the unfluted part. Tear along the dotted line.

The 22 rimfire rifles with ring bulges I’ve fired did not appear to be adversely affected, if the rifle didn’t shoot well there were other problems. In  my observation the bulges in rifle barrels I’ve seen were almost always caused by trapped liquid. Shotgun barrels were a different story, lots of things can cause them to bulge. 

I wonder if my cobber, the gunsmith, could offer any enlightenment on how much liquid it takes to cause a ring bulge.