I did this to a Ruger .44 magnum, KS411n, 10.5" silhouette model at Greenwood Gun Club, in Brazoria, Texas, during a silhouette match. First bullet stuck in barrel about 2" past forcing cone. Then, apparently suffering from acute brain failure, I let another one go. It split the barrel on top, blew the ejector housing into my gun carrier. My wife was spotting for me and got lots of gravel, etc., blown over her legs. A buddy of mine at the match offered to put a new barrel on it, but I thought maybe Ruger would do so. I took it to the gunshop in Austin, that I had bought it from, and the owner said "no problem, I'll send it to Ruger for you". He calls me two weeks later, Ruger is not gonna put a new barrel on it, period. Not only that, their not sending the gun BACK, either! He says they offered a new Super Blackhawk to me for what he would pay for it. Well, thats what I ended up doing, but I get a real head of steam built up when I hear all the glowing reports of Ruger's factory service.
Even though I don't know the cause of the bulge it wasn't catastrophic, it was only a few 100s of a inch but noticeable.
If it had been any worse I probably wouldn't have bought it even at the bargain basement price I did.