I'm probably going to come across like an @$$, since this is my first post here, but here goes...
There's a LOT of misinformation out there on so-called "Pre-Bs." First, neither CZ-UB or CZ-USA use the term "pre-B." You won't find any original Czech-language sources that use the term "pre-B."
75B/85B pistols have an automatic internal firing pin block safety. The "B" doesn't stand for "block," or so I have been told. Back in 2002, Martin Brodson, the former VP of CZ-USA, informed me that this just a coincidence. That is, "B" just happens to be the second letter in the Roman alphabet.
I emailed CZ-USA recently for further clarification, because the Czech verb for "block" also starts with "b." Specifically, the Czech-language version of "firing pin block" is "blokování zápalníku." That is derived from the Czech verb for "block," or "blokovat/zablokovat." The most common noun for "block" is "špalek." (I mention this because I always think of it as a noun, not a verb.)
CZ-UB uses the terms "Type A" and "Type B." Most collectors refer to a significant Type A variant as "Transitional." As far as I can tell, "Transitional" was not a term originally used by CZ-UB. CZ-UB's own book on the subject, CZ 75: The Birth of a Legend, by Pazdera & Skramoussky, doesn't even discuss the existence of Transitional models at all, much less use the term.
Serial production of Type A pistols began in 1977 and ran to 1992. They do not have an automatic internal firing pin block safety device. As a general rule, they have spur hammers, rather than the current rounded style. As a general rule, they have a rounded, rather than square, trigger guard. Although most people associate the round trigger guard and spur hammer with the Type A, there are variants made for a contract with the Turkish Armed Forces from 1988 with a rounded hammer, just for example.
The original CZ 75 design had some internal improvements in the firing pin system from 1977-1979 and added a half-cock notch in 1980. Also, the external appearance changed from the flat "short-rail" design to the current design in 1980. The magazine well has become larger over time; a significant change in size occurred sometime in 1985.
Relatively few Type A pistols were imported into the U.S. through normal channels prior to 1991. Prior to 1991, there were severe importation restrictions on arms from Warsaw Pact nations. Changes in the Fed. regulations and the status of the CSSR allowed these pistols to be imported on a larger scale beginning in 1992. "Pre-Ban" is a misleading/confusing term, because the differences in Type A and Type B pistols were not dependent on Fed. regulations per se, but they definitely played a major factor. The BATF uses a "points system" for importing foreign-manufactured handguns, and the automatic internal firing pin block does aid in their importation. (Significantly, the 85 Combat model does not have the block, but it has other features that give it off-setting "points.") The automatic internal firing pin block safety was designed and tested in 1991-1992.
For many years, most Type A pistols in the U.S. were 1985-1987 models imported by Bauska of Kalispell, MT. According to internet myth, the BATF fined Bauska out of existence, but I have not been able to confirm this. Most of the rest were Frankonia models purchased in the former West Germany by U.S. servicemen. Frankonia essentially purchased 75/85 series pistols and "customized" them in order to "legalize" them for sale in Western Europe. Some Frankonia models are heavily modified (finish, sights, trigger, etc.) and some are just "re-branded" CZ-UB models.
In the last 10 years or so, quite a few Type A military or police surplus pistols have been imported as "used" guns, so it would be helpful to inquire about the import markings. The Bauska imports are marked "Bauska/Kalispell, MT." The used pistols imported more recently will have various import markings. The Frankonia pistols will not have import markings.
In 1995, the Type B models were introduced. These are also called the "B series," etc. in Czech-language sources. Both the CZ 75B and CZ 85B replaced the earlier models. Type B 75/85 series pistols have the automatic internal firing pin block, a square trigger guard, modernized external controls, and a rounded hammer. The current CZ 85 Combat resembles a Type B frame, but lacks its true defining characteristics: the automatic internal firing pin block safety and the lever that actuates it. The B series also marked the debut of most 75 series variants. That is, there is no Type A CZ 75 in .40 S&W, with a decocker instead of a manual safety, etc. CZ-USA has only imported Type B 75/85 series pistols (unless you count the 85 Combat as some sort of exception). These are by far the more common handguns in the U.S.
"Transitional" models were manufactured from 1992-1994. In my mind, these are best understood as a major Type A variant. Essentially, these are handguns produced with a Type A slide on what appears to be a Type B frame. A "transitional" does not have a Type B frame in the strictest sense, since it lacks the firing pin block lever. In other words, these models have a square trigger guard and rounded hammer like a Type B, but they have the slide and external controls of a Type A. I have seen pics of 1994 transitional models with the modernized external controls associated with the Type B. There are also transitional CZ 85s, but identification gets very complicated, as the Type A 85 Lux and 85 Combat models were the basis of the Type B pistols. Transitional pistols are comparatively rare (due to the short time they were produced), but Magnum Research and Action Arms imported these models in some quantity, so they are not particularly rare in the U.S. The Action Arms and Magnum Research imports seem to be 1993-1994 models.
To Answer Your Actual Question: It depends.
The older 15 round Mec-Gar magazines will fit Transitionals. They may be tight, but they will fit and function. I don't own any of the 16 round Mec-Gars, but I have been told that they fit as well.
The 15 round Mec-Gar magazines fit in my '86 Type A 75, but they are extremely tight. They will fit and function in my '82 Type A 75, but they are too tight for reliability. They are incredibly difficult to insert and remove, and using them creates visible drag marks on the mag body. The '86 will mark the bluing, but not actually stress/mar the metal itself. Based on my reading, this is pretty consistent with other peoples' results. In other words, the further back you go, the more problems you will have with them. Both of these still have the magazine brake installed. Don't remove the brake, by the way. (I can elaborate if necessary.)
The OEM CZ 15 round magazines that pre-date CZ-UB switching to Mec-Gar fit better in Type A pistols. They are tight in the '82, but they are "correct" for the '86, as far as I can tell. I bought mine from CZ-USA in 2001. Another one I have came with my '96 75B Mil, which I purchased in 2000, IIRC.
All of the "short-rail" Type As I have seen came with magazines marked with the pistol's serial number. That's probably not a good sign. I have been informed by another member that most of these serial #s are etched, but I have seen photos of a few that had the serial # stamped into the magazine body.
My '82 and '86 Type As only came with one magazine each. The cardboard box for the '86 only has one magazine "slot." The box, manual, and accessories for the '82 were long gone when I purchased it.
The magazine that came with the '82 didn't have a serial # marking, but it is virtually identical to the Czech OEM magazines I purchased in 2000-2001. It is slightly thinner at the top of the mag body. The older Czech mag has a lighter finish than the later ones. (It's blued, but it looks sort of "grey.")
The magazine that came with the '86 Bauska is completely identical to the Czech magazines that I purchased in 2000-2001. I could probably get them all out and identify it, because it was marked by the magazine break.
I also have a '93 Action Arms Transitional, but the two magazines that came with it were beat to hell. I seem to recall that one was a Tanfoglio magazine, and the other was the same as the Czech magazines I have described. I'm not sure if that pistol was supposed to come with one or two magazines.
