I tend to like obsolete rounds, not because they are unpopular or unusual (although that does play a part) but because often they fill need that no other cartridge can do as well. I do like the look on peoples face when they ask what I am shooting and I say, ".250-3000" as opposed to saying ".243", but generally I am more interested in performance.
The reasons why some chamberings fall from favor and become obsolete are mysterious. Some you can understand but others "should" have been great....and never were.
Some obsolete chamberings are gone for a good reason.....they never filled a need. I don't care for the .284 Win. It never produced any ballistics that couldn't be obtained by the .280 and were surpassed by the 7mm Mag. It did this with a rebated rim that created more problems than it solved. The .284 had no reason for existing.
The 6.5 and .350 Remington Magnums fit into this "no reason to exist" category. They replicated the ballistics of other rounds based on the .30-06 case, were beaten badly by true magnum cased rounds....and did it in some of the ugliest rifles ever marketed. If someone WANTS a cartridge to fail.....they should study these rounds history.
Other rounds that have fallen from favor were exceptional in performance and in some cases never equaled. The .220 Swift is a favorite of mine. It is still the fastest commercial varmit round ever produced. The .22-250 comes reasonably close but falls just short. The .220 was cursed by being introduced too soon. Powders and bullets available at the time gave it a reputation of being hard on barrels...which it was. With modern steels and powders it is no more so than any other high-intensity .22 caliber round....but the damage was already done in the public's mind and it drifted into oblivion.
A round I really like is the .25-20 in a rifle. It is the closest thing to a reloadable .22 LR (with 86 grain bullets) and can exceed .22 Magnum ballistics as well with lighter bullets. I guess there just wasn't a "need" for a reloadable small game cartridge, but I always liked it No other round fills this need as well.
I also like the .32-20. Not so much in a rifle, but in a handgun. I really can't justify this one so well as other rounds perform similarly with less trouble (thin bottle-neck cases). When loaded to it's capability in a modern revolver the .32-20 will outperform the .38 Spl and come very close to .357 performance in the field. I like it a lot.....just wish I could make a more favorable argument for why it shouldn't have failed.
The .250-3000 is perhaps not truly obsolete, but it's close. I love this round. True it will do nothing that the .257 Roberts won't (another round that just barely hangs on), but it does have one trait that makes it a favorite.....it fits in the Savage 99 rifle. That's reason enough to exist.
Another round that is on it's way to disappearing is the .35 Remington. It is truly a great close range round, but unfortunately that type of hunting is mostly in the past. Modern hunters don't seem to want a close range "thumper" no matter how well it does it's intended job.
The .375 Winchester is also a personal favorite, but it will suffer the same fate as the .35 Remington.....for the same reason. No interest by modern hunters. It is a great short range round, but was unlucky enough to have been introduced just as the taste of shooters was changing. It never had a chance and even though it outperforms the .35 Remington was never even as popular as that failing round. Had the .375 been introduced in the 1950's it might have become a legend in the deer woods.....but we'll never know.
One of my favorite handgun cartridges is possibly also on it's way to oblivion. The 10mm seems to keep hanging on....just barely....so it may be a while before it becomes obsolete. It's entire history has been tenuous. Introduced in the Bren 10.....which never really succeeded.....it was left without a platform to use it. Then when the 1911 was modified, it ran into problems with frame cracking. The FBI (and it's limp-wristed shooters) did the 10mm no favors when they decided to download it. Then the .40S&W stole a lot of it's thunder when it was realized the same weak ballistics could be had in a shorter cartridge. Through all this the full-loaded 10mm remains a very powerful round. One of the few that should be considered in a "normal" semi-auto handgun for hunting purposes. The 10mm SHOULD survive, but may not.
The last of the obsolete rounds I like and use often is the 7.63 Mauser (duplicated by the 7.65x25mm at higher pressure). Don't know why I like this one so much but it is one of my favorite "fun" guns in the C-96 Mauser pistol. It is already obsolete and will likely disappear totally due to a lack of firearms so chambered and the potential danger when 7.65x25 ammo is substituted into older guns.
