Yup, those are spider webs inside the barrel
As a caveat, this gun just came into my possession like this:
As shown in the above image, that poor J-frame .38 was stored in the back of a roll-top desk for years and, when inspected, the cylinder contained five greenish Nyclad SWCs which probably dated to the Carter Administration and the barrel had a pretty decent cobweb lacing from the muzzle to the chamber complete with a couple of emaciated visitors who likely checked in sometime during the Reagan-era.
Would the gun have gone boom if needed? Probably. Maybe not. After cleaning and inspecting– as well as switching to some rounds that were a little fresher– the popgun went bang 5/5 times and was ready for more. Thankfully it was apparently put up clean and just got dirty over time through neglect. The worst thing that it came away with was some brass corrosion and a sprinkling of surface rust that showed itself once the dust was cleaned away.
So how often DO you clean your guns?
I talk about that in my column at Tac44.com.