So I'm sitting at my desk on day, contemplating the arrival of my RIA MAPP FS 9mm into which I will install a Rock Island .22 TCM9R barrel to effect ownership of a .22 TCM pistol here in the great State of Khalifornya. While watching a video about the MAPP, happened upon one of the usual and expected comments about how the only "real" CZ is the versions made in the Czech Republic, and all else are poor imitations not worthy apparently of even having a video of them. Well, this inspired me for some reason to see if the RIA .22 TCM9R barrel might fit into my CZ-75B .40 S&W. Well...it ALMOST did! Careful examination revealed the only thing needed for it to "drop in" was to lower the extractor recess a few hundreds to clearance the .40 S&W extractor. Once done, I suddenly had a .22 TCM CZ-75B!
Okay, so extraction is going to be a problem...maybe not. I tapped out the retaining pin and examined the OEM extractor, bearing in mind that any modification to make it work on a .373" rim might prevent it from being used for the .40 caliber,.425" rim. Using a Dremel I reduced the clearance pad while check fitting to the slide until I got good tension on a TCM rim. Cleaned it up with a small file and reinstalled. Checked function and it delivers positive extraction! I also checked the feed of .40 S&W and they also work. Even with the extractor "rotated" further inboard, the original rim relief is still just level with the contact surface inside the extractor channel. Certainly the extractor offers more resistance to the big .40 rim, but it was still easy to chamber using hand pressure.
I checked the fit and feed of my new EAA Witness 9mm mag, and it too works perfectly, so now I'm all set to do some testing.
While doing all this it occurred to me that if the TCM barrel drops-in to the CZ-75B, the 9mm barrel in the RIA MAPP will certainly "drop-in" to my CZ-75, which means I now have the capability of shooting .22 TCM9R, 9mm, and .40 S&W out of my CZ-75B!
Who would have thought a casual notion would have worked out so well. BTW, the .40 S&W barrel diameter is .550", as is the MAPP barrel at the muzzle. Older, 9mm CZ's use a .500" barrel with bushing in the slide and would not be such an easy conversion...as always once has to do their own experimenting. That said, since the MAPP TCM barrel is only .550 near the muzzle with the main section being .500", it wouldn't be hard to turn it down to fit a 9mm slide nose....or so it seems until someone tries it.
One last thing. For those with .40 S&W CZ-75B pistols, both CZ and EAA (Tanfoglio) offer 9mm barrels in .550" diameter up to 6" in length. From what I have discovered, they would seem to be at least a near-drop-in, if not drop-in fit to the .40 slide, and require just a touch of work on the extractor to work flawlessly.
