Remo223, 50 years is a general guideline. There are guns less than that on the C&R list.
The CZ 82 is on the list, you just have to check the listings.
Indeed. What it basically boils down to is a license for collectors. Not required to collect, but just to make it easier on us. The basic thought is that ANYTHING more than 50 years old has some collector's value. However, some other guns less than that may also have collector's value. The CZ-82 for example, is on the list because it's parent country, Czechoslavakia (sp?), no longer exists.
Overall though, you just kinda have to accept what they list as C&R. There are a ton of guns with collector's value that are less than 50 years old and will never make it on the list.
Also of note: while in most cases "the receiver is the gun", that doesn't apply for C&R purposes. The gun must be in original condition with original spec equipment. It's a grey area here. If you replaced the firing pin on a CZ-52 with a newer one that's not as brittle, then the overall purpose and design of the gun is unchanged, so it's still C&R. Same thing on period-correct replacements. If you get a gunwith a broken stock and use one of the original contour replacements from somewhere like Boyd's, then it's still the same basic type of gun, so your'e good. On the other hand, if you take an old Mauser rifle and rebarrel it, drill and tap it, put on a new monte carlo stock, and reblue it, then though the receiver might still be 50 years old, as far as the ATF is concerned it's no longer a qualifying C&R gun. Sporterizing and other such modifications essentially "reset" the build date. It technically would be C&R again 50 years after the sporterization, but that's something that's mighty hard to prove.
Also, while pretty much all of the big surplus dealers like AIM, SOG, CAI, Centerfire, etc, accept a C&R no problem, there are many sellers on places like Gunbroker who won't accept a C&R - particularly for guns whose age is the qualifier rather than being specifically named. In those cases there's not much you can do - you just have to buy elsewhere or go the traditional route through a dealer.
Due note though: your C&R acquisition record (bound book) must be updated for ANY eligible firearm that comes into your possession - whether you used the C&R license to obtain it or not. That means that if you buy an eligible gun at a gun store and still do the standard 4473 and NICS check on it like any other gun, you still have to come home and log it into your records.
Overall though, I wouldn't look for the 50 year mark to be reduced anytime soon. I'm surprised the C&R program is even still around. Seems like something the grabbers would be fighting tooth and nail, but I don't think most of them are too aware of it in the first place. I don't want to bring it too far out into the spotlight. Heck even one older gunsmith that I visited to do a transfer on a gun was complaining that C&R licensees shouldn't be able to get old 1911's because it's a design that's still in common use today. This was supposedly one of the "good guys" on our side, but was basically viewing the C&R program as if it were some loophole.