Thanks for the info Iowegan and 2400. Those were great pictures and make it easy for even a old fool like me to understand. I stumbled onto the NT style primer pockets quite by accident. Most of my .40 brass is plain old WWB and Remington in the white and green box. I had one box of Federal and the first thing I noticed about them was the large flash holes. At first I thought I was seeing things, but I gauged them and confirmed my suspicions. I didn't try priming them, so I didn't notice the the primer was crimped like the old GI brass. I decided that I didn't want any part of them because of the flash holes. (No genious on my part - I just thought it was a bad batch of brass.) I used to ream out the flash holes on .38 Spec cases, prime them and use them for training blanks. Also used to do that and load parafin bullets for point-shooting practice. In both cases, without the enlarged flash holes, the primers would back out and freeze up the revolver. I always marked the case heads with a red permanent marker and never used them for live ammo.
I'm sort of like a boxer who has come out of retirement. From about 1968 to about 1985 I loaded tens of thousands of rounds of ammo for rifle, revolver and .45 auto. For reasons explained in other posts, I quit for about 20 years and have just now begun to load again. I remember most of what I learned in the past, but it is coming back in stages. I've always been a very cautious reloader. I always clean and then inspect my cases before trying to reload them. While this is time-consuming, it has saved me a lot of grief over the years, especially when loading for any semi-auto pistol or for high intensity rifle rounds. I've never been much on pushing the limit on max loads. When I load for autos, it's always just for practice and they are ususually mild. Just enough to function good and be halfway accurate. While I trust my reloads, I prefer to use tried and true factory defense loads for serious social encounters. Revolvers on the other hand, are a different story. I start low and work my way up until I find a good compromise between accuracy and velocity, but I never exceed published maximums. Because I'm a bit paranoid, I've never had a double charge or a case with no powder. (Knock on wood)
There are a lot of people who don't like the .40 S&W for one reason or another. I don't have a lot of experience with it. I've only shot about a thousand rounds of it total, most of it in a Springfield XD and maybe 300 rounds in a couple of different Ruger P944's. I have 4 9mm's, 4 .45's and one .40 S&W. I sure don't need a .40 and I feel better armed with a .45, but the ones that I have (had) are accurate and fun to shoot. The XD I had was a fine weapon. I had zero malfunctions of any kind. I had a little trouble getting used to the trigger and while this is no useful criteria for judging a gun, I thought it was butt ugly. In my case, I guess it was an experiment and ultimately just an excuse to buy one more Ruger.
Again, thanks for your input - I WILL be careful.
Tom