mljdeckard, I started out with 1911 and yes, the two platforms are "different" and accuracy from tightly locked up barrel/bushing and clean SA trigger has accuracy advantages that Glock simply cannot compare.
However, the OP is regarding the accuracy of 9mm vs 40S&W. Since there are many "production" class match shooters who are quite accurate with the 40S&W caliber using various pistol brand/models (Glock, M&P, CZ, etc.), I think we could rule out the argument that 40S&W is "inherently" inaccurate.
Buck13 said:
is there any inherent difference in accuracy between the 9 mm and .40SW?
Many shooters often start out with 9mm, either shooting someone else's pistols or buying one. Like many "firsts" (remember your first car?) that often meant thorough familiarization of the pistol, cleaning and practice. I remember when 40S&W pistols started to become popular with LE agencies and most people trying them out, their initial impressions were like, "dang, it kicks/recoils much more than my 9mm" or "I can't shoot it as accurate or fast as my 9mm" Then I started hearing that 40S&W somehow was "inherently" not accurate.
Good thing they didn't shoot 10mm pistols!
As some posted, if we transitioned from 22LR to 9mm pistols, we probably would have made the same comments.
Buck, I can shoot my G17 along with G22 and they are both accurate. G17 will have less felt recoil and someone not familiar with 40S&W's recoil will take longer to perform follow-up shots. But with practice, comparable double-taps can be performed on both pistols (match shooters do it every week on a national basis). I use Lone Wolf 40-9 conversion barrels in G22/G27 so I can practice with cheaper 9mm rounds loaded to almost +P pressures to give me a comparable recoil practice as 40S&W rounds. When I am done at the range, I drop in factory 40S&W barrels and they are good for SD/HD duties. BTW, you can also get 40-9 conversion barrels for M&P40 pistols.