Thread: Who's seen a rimfire do this before

I've seen this on an old 17 Remington I had.
The hypothesis the gunsmith and I came up with was that the rifling at the end of the barrel was on a 'loose' spot that only gave contact with one side of the bullet from one side of the barrel.
The .17 bullet being so light was then exiting at an angle that made aerodynamics unstable.

That was his and my idea anyway. He ended up cutting 2" off the barrel and recrowning which got it shooting correctly.