.30 is not mainstream or anything close. .177 and .22s are "mainstream. There are thousands of them out there for every .30 cal. .30s with pellets give 80 FT LBS or better, plenty for smaller Deer or self defense at close ranges. Regardless, that has nothing to do with drawing a line to separate small bore from big bore air guns.....in 10 years .30s may become common enough to list with the small bores, but I doubt it, since few people really need them, they use a lot of HPA, and until State laws give you something big enough to legally hunt with a .30 cal. In my state, there is nothing to hunt or defend myself against, that a hot .25 can't handle. My vote is still for big bores to include .257s and up, just based on how few there are, compared to the hundreds of millions of .177 to .22s. even the ,25s are not common place. If Michael wants to draw the line at .357, that's ok with me too, It is not that big an issue to worry about.