I've never had an issue with TSA. I have even found out that those guys have a sense of humor. The only time I saw anything out of TSA was when a counter agent sent me over with my guns by myself - The counter agent is supposed to escort you, and in some airports actually carry the gun case.
TSA has the ammo pounds rule. However, Minneapolis puts a limit on the number of rounds that is exactly half the weight (in .45 acp). I found out they don't like it when you take the surplus back out to the pick up in the ramp.
I have always understood the five gun rule, but the last time I flew I took four in one case. It was no problem in Minneapolis, and it was no problem at the counter in Phoenix. However, while sitting and waiting to board, with my Kalispel case on the tarmac, the XYZ airline "gun guy" called me up over the PA and made a big deal about five guns in one case (I bought one in AZ). He claimed that it is max of five with no more than two in each case. When I asked how I was supposed to get them back home, and he learned that I had flown down there that way, he explained that he WAS the "gun guy" and he would bend the rule, but don't ever try it again. By this time everyone on the plane knows that I am some redneck son of a bitch and wondering what kind of arsenal I have in the cargo hold. Way to keep the public calm dude!