Re: Barrel Erosion ?
Yep that is throat errosion. How many rounds do you have through it? If the number is approaching 1,200+ it may well be time to start looking for a new barrel - especially since it is now showing visible signs of accuracy degradation. You can chase the lands, to get your jump distance back to the original distance, and that may bring back teh accuracy for a while, but I suspect you are on the downhill slide of a useful barrel.