I just picked up a nice looking, fully functional Remmy M121 pump action rifle. on close inspection I find that the bbl is slightly bulged about 5" from the muzzle.

The bulge isn't enough to see with the naked eye, and I don't see any interior damage to the bbl. I haven't had a chance to mic it yet, so I can't exactly say how many .001's it might be over.
Should I refrain from firing this oldie ( 11/1948 ) or will it likely be O/K ? It's all original, mostly turned plum brown patina but "purdier than a new set o' snow tires", so I don't really want to change out the bbl if I can avoid it.
Any suggestions are welcome!
Glenn
"If you know how many guns you own, then you don't own enough!"