& perhaps a few bulges?

There is an interesting bit of discourse on one of the RF boards where the consenses seems to be that shooting a bbl with too much oil in it is the primary cause of 'rings' in .22 RF bbls. The thought being that the bullet overruns the small wall of oil it is pushing and that causes a 'ring' .. or perhaps in some worse cases a bulge. I don't pretend to know if that actually happens or not, but I have seen rings in RF bbl's that did not show any outward bulge and others that clearly did ... trying to shoot out a squib's stuck bullet seems to be normal method of making bulges though.

Just curiosity on my part, but anyone ever heard this 'too much oil in the bbl.' theory applied to a shotgun? Think its possible with today's plastic wads? What if someone greased the bbl?

Personally, for shotguns, I'm inclined to think obstructions like a bit of Kapock or stuffing from an old gun case that got in the bbl., a blooper that left the wad stuck or a felt or cotton patch that was inadvertently left in the bbl from a previous cleaning as being the more likely causes of a ring or bulge, but the RF thread got me to wondering about what if someone slathered the bbls down with RIG or some other viscous protectant. Would it/could it cause a 'ring' or a bulge? Any thots, what say you?

I had a Colt woodsman Match Target that had a ring just forward of the chamber, apparently caused by too much oil left in the chamber or barrel. It was only visible from the inside, looking through the barrel and did not affect accuracy at all. It still shot very well.

I can't speak to a rifle and perhaps should not to the shotgun.
But---I have never thought of shot as being a solid but for ball or slug. I have always thought of them as fluid as opposed to solid.
It would go against this thinking to expect that oil could cause a bulge in a shotgun.A large blob of grease perhaps, but not oil.
It would seem to me that oil would have to be as viscous as 90 weight gear oil to "puddle" in a barrel, thus causing an obstruction.
It surprises me, as well, to learn that excess oil my be the culprit in a barrel bulge in a 22 RF. Is it not customary to coat a bullet with honing compound and fire to clean a rusty barrel?
I have been told to do this by more than a few shooters. Would this not cause more of a problem that oil in the barrel?
Live and learn, as they say.
So my question. Where in the barrel is this found? Seems that the bullet would push the oil from the grooves as it traveled up the barrel and have to be "overloaded" somewhere far from the action.
Best,
John

A bullet carrying the oily lapping coumpound from a standing start would behave differently to a bullet hitting a "puddle" of excess oil while doing several hundred or more fps in the confined space of a barrel - the latter could conceiveably cause a problem.
obstructions as flimsy as cobwebs have been suspected of bulging a gun barrel...
Hard to prove either way once the evidence has vaporized!
Black powder cartridge rifle shooters are aware of chamber ringing caused by different types of waddng and low levels of propellant to case volume. I understand one theory is that the pressure wave runs into the back of the still stationary bullet and is deflected out against the chamber wall just behind the bullet.
RG

Most bulged .22 rf bulged barrels that I have observed have been on .22 semi autos. This could lead one to believe that is a bullet stuck in the barrel that caused the bulge during rapid fire. I think that most .22 rf barrels are cleaned with a sovent rater than oil and then left as is, shouldn't cause an obstruction. Let's face most .22 rfs don't get cleaned til they cease to function. Just some observations after 15+ years of helping out at the Gunsmith's Shop.

for shotguns it's snow

Cadet:
Is this what some refer to as riveling(sp)? I know this as a continuous series of internal barrel rings. Always thought these to be caused by a certain harmonic situation. Seems to me that you may be adequately explaining how this happened. I don't remember seeing it on a "modern" shotgun. Say post 1925. Seems it is always on black powder period guns.
Best,
John

John,
Not the same as rivelling I don't think - there is a distinct ring which occurs in the one spot - a spot which corresponds with the back of the seated bullet. After a while it can make extraction nigh on impossible because the brass fireforms into that groove. This, of course, is in rifles.
In shotguns I have also heard the theory that small, pushed out dimples on the bottom of a barrel can be caused by shot leaked out ahead of a cartridge - recoil from first barrel jolts pellets out of the second barrel cartridge with a dodgy crimp. Second barrel fires and treats the leaked shot as a small obstruction.
There are so many mysterious ways for a barrel to suffer!
RG

Light bulb time. Thanks, cadet.
Best,
John