Mystery ring inside barrel.

[stevelyn]

I have a Win. M-290 .22 semi-auto that is more or less my go to .22 since I can shoot shorts out it.

Yesterday I was giving it the "once in a blue moon" cleaning and noticed a ring inside the barrel about 1 1/2 to 2 inches from the muzzle. From the looks of it, the ring is about 1/16 to 1/8 inch wide, uniform in appearance, appears to have slight pitting or distortion and the lands and grooves are still visible in the ring itself.
There this nothing visible or tactile on the exterior of the barrel in that area (approximately about or slightly rear of the sight ramp).

I've never noticed it before and it dosen't look like a manufacturing defect. The only thing I can think of of how it could possibly have gotten there, is shooting it with a bore obstruction. I have shot plenty of Super Colibris out of it. Although I don't ever recall having a bore obstruction or a squib load with either a Colibri or standard load.

Could there be another explaination for this ring?

 

[Foxman]

Some rifle makers actually choke the bore towards the muzzle to increase velocity and maybe accuracy. I havent noticed it on any of my 22 rfs, but you can just detect the choking on some of my cf rifles, just my #02 worth

 

[deadin]

In my experience a ringed barrel usually means the gun has been fired with an obstruction (i.e. bullet) in the barrel. Did you buy this gun new or is it possible that it had the ring from before and you just didn't notice it? Having a .22 short stick is not all that uncommon. If you were playing "machine gun"
(which can be a lot of fun with shorts ) you might have had one stick and then clear with the next round. In a blowback auto the breech would open and the gun would still go "Bang" although with a slightly different sound that may or may not be noticed in a rapid fire string.

Dean