I was grocery shopping and walked by the magazine aisle in my local store. I thumbed through the June/July edition of Handguns magazine(June/July issue already?). I came across an article on five handgun calibers on the verge of non-existence. Two honorable mentions were the .357 SIG and the .45 GAP. I could possibly understand the .45 GAP, but the .357 SIG does have some loyal fans(I have seen a few of them here). What are some handgun/rifle calibers that you think will go the way of the dinosaur?