I will offer that TC has a well known record of "some" rimfire barrels that had brass bulge issues. Probably the best known was ALL of the first 17HM2 barrels bulged brass, even on brand new frames. I had one of the first barrels, it did it, and Tim P. and I spent some time on the phone discussing it several times. In this case it was determined the early brass itself was the problem more than their barrel tolerances, but both were corrected anyway. I never bothered to do anything about my barrel, the bulge was minor even with the early ammo, not enough to be critical, and it was a tack driver. But some others that have been more severe have been head spacing/worn frames and some tolerance issues with the barrel itself that TC gets all the credit for.
From the picture at RFC this particular one has a more severe bulging than any I have seen personally from a Contender, 3-4 times more than those early 17HM2's. Might get by for a while without blowing brass, but is it worth finding out the hard way when it does (and it will eventually from wear)? I wouldn't live with it myself, no matter how well the barrel shoots. It will spit when brass blows, while maybe not a severe safety issue on a rimfire, still an unpleasant one and with possible injuries.
A personal example... I finally retired a Winchester 1906 when it started spitting almost every shot. My ex wife or my son getting there face and hand dusted was not acceptable, so I retired it mid 80's. The rifle was 1910 vintage. I gave it to my wife in 1968, had sleeved the shot out barrel in about 1971, again about a dozen years later. But the action was so worn it was just time to retire it. It now resides in Fred Smiths Winchester collection as a wall hanger (Bullberry).
