One more statement. I've posted this from time to time on gun boards, but everything that needs doing in conventional ballistics has been done. The 10mm was the last truly innovated development that I recall, a large caliber magnum round for the auto pistol. Any other ideas that might be innovative are few and far between. As stated, the Sig is no better than the .40 which is somewhat better than the .45 iin that it's a big bore high energy round that fits in high cap magazines. Ballistically, it doesn't do anything the .45 ACP +P won't do, just that the gun will hold more rounds. There are high cap .45s, of course, but they're rather large.
In the world of rifle cartridges, there are the new short magnums, putting magnum power in a shorter, handier rifle. However, ballistically, I ain't sellin' my 7mm Rem Mag. The is no real advancement in ballistics, just the shape of the cartridges and the type of guns they fit in. I won a .25-06 BDL at a gun show some years ago and traded it immediately for a Remington M7 stainless I wanted...why?....I have a .257 Roberts which when handloaded, practically apes the factory .25-06. The .25-06 was introduced in 1970 by Remington, brought out of the world of wild cats with all sorts of glamor and glitz and the magazines all heralded a new era. Well, the .257 Roberts can do anything the .25-06 can do and in a short action gun! What actually killed .257 Roberts sales was the introduction of the .243 by Winchester as THE small bore deer/varmint round. The .257 factory ballistics at the time were about equal and the .257 could shoot heavier bullets for heavier deer, never mind what a handloader could do for it. The .257 returned for a period when Winchester loaded (+P) loadings for it, really what the Roberts should have been all along and not even up to what handloaders had been doing with the cartridge, but it got a resurgence in popularity for a brief period, then died again. But, it ain't like the .250-3000, the .243, the 6mm Remington, nor the .25-06 are much different in what they can accomplish, yet in age old deer rifle caliber arguments, one will champion the 6mm Remington to another the .243 and they'll fight like it was important or something. I just don't get it.
Anyway, enough with the rambling. I think most cartridges like the .45 GAP that come out now days are just marketing gimmicks, nothing more, nothing less. Most everything that needed doing has been done. The .30-06 will STILL kill everything in the lower 48, that hasn't changed. But, it's fun to watch some guys tout the .300 WSM over all other rounds as the best of the best. I mean, yeah, it's as good as a .300 mag I guess, so? It's been done. I don't want a .300 mag in a 6 lb Remington M7, I can tell ya that! I've fired .300 mag in a long action 8.5 lb rifle and it was tolerable, but a 6 lb gun? And, like I say, the 06 is plenty. The .30 US caliber of 1906 is STILL the cartridge all other American game guns are compared to. Why bother recreating it 30 times over? <sigh>