Most shooters today probably have no idea of who either Warren page or Fred Huntington were. We will go into that at another time in a different chapter, but for now it's enough to know that these two fellows had more to do with popularizing cartridges using .243-inch-diameter bullets than anyone else. Over time, their experimenting led to the introduction of the 243 Winchester by Winchester and the 244 Remington by Remington, obviously. The 243 Winchester, introduced in 1955, caught on immediately. It was chambered in the Model 70, and could be had in the Featherweight, Standard, and Varmint versions. The cartridge is nothing more than the 308 Winchester necked down to accept .243" bullets. It has a very short neck of just 0.241 inches in length, in combination with a shoulder angle of 20 degrees, which I think contributes to kind of rapid throat erosion. Nonetheless, it is a very effective long-range varmint cartridge and a fairly adequate smaller big-game cartridge. The 243 shoots well with a wide variety of loads, and is therefore easy to load for. I prefer neck-sizing most cartridges (there are exceptions), and with the 243 this is best accomplished by using a dedicated neck-sizing die.
Our subject cartridge is similar, and at the same time very different. The 6mm Remington started out as the 244 Remington. It was also introduced in 1955, but the only rifle available for it was the Remington Model 722. When comparing the 722 with Winchester's Model 70... Well, there was no direct comparison. The 70 was a living legend, and the 722 Remington was pretty cheap. No varmint version. No lightweight version. Sales of the 244 were lousy from the start. And there was another factor; 243 factory ammunition was available in 100-grain loadings, while the top weight for the 244 was 90 grains. This led to speculation that the 244 was not as well suited to deer hunting, and perhaps it wasn't. The bullet weight situation was a result of the 244 coming out with a 12-inch twist instead of the 10-inch twist of the 243 Winchester. The 12 twist wouldn't stabilize sharp-pointed 100-grain bullets. Remington's thinking was that the cartridge would perform better with varmint-weight bullets in a 12 twist. Maybe they could have pulled it off if they offered a varmint rifle with a heavy barrel.
Countless comments have been made about the failure of the 244 being directly related to the 12- versus 10-inch twist, and the resulting 90- versus 100-grain ammunition. I think it was poor marketing and the lack of a corresponding rifle lineup. As a cartridge in and of itself, I prefer the 244 (6mm) over the 243 Winchester. The 244 was created by necking the 257 Roberts down to .243 inches, and making the shoulder a fairly sharp 26 degrees. Neck length is 0.351 inches; a full 110 thousands longer than the stubby 243 Winchester neck. This leads to wonderful hand loading advantages. Case length is 2.233 inches compared to the 243's 2.045 inches. Consequently, the 244/6mm has more powder capacity and can produce more velocity. There is some taper in the 244/6mm case, just as there is in the 257 Roberts and its parent, the 7X57mm Mauser. While some folks prefer a case that has very little taper, I find that the 244 is ideal for almost complete neck sizing with a full-length die.
I keep mentioning the 244 in these comments about the 6mm Remington, and that's because Remington thought that a name change might boost sales. At the same time, they changed the twist from 12 inches to 9 inches and began to offer factor ammunition loaded with 100-grain bullets. This apparently didn't help much. Remington offered several versions of the Model 700 chambered for the 6mm over the years, and that has dwindled down now to essentially nothing. The 243 Winchester reigns.
There are a couple of problems with the 6mm, as I see it. First, that same longer case that provides a capacity and velocity advantage also requires some bullets to be seated a little deeper than I would like, if you expect them to fit in a typical short action that accepts loaded rounds of little more than 2.800 inches in length. In other words, the 6mm is just about too long for a short action with a magazine. No problem, however, for a single shot such as a 40-XB. Secondly, the 6mm can be quite a bit fussier than the 243 Winchester when it comes to working up a load. As said earlier, the 243 handles a wide variety of loads quite well. Not so for the 6mm, at least in my experience. But, when you do find that load for whatever your mission is, whether that be varmints, larger game, or target, it can shoot exceedingly well. Before writing this, I pulled out a file that had some 6mm groups in it. Little-bitty clusters of five shots piling in on one another.
The nine-inch twist of most 6mm rifles, which is also the current twist for a lot of factory 243 Winchesters of recent years (9 to 9 1/4 inches), has done a nice job of stabilizing Hornady's 105-grain A-Max bullet, which has produced very fine long-range accuracy in some rifles. Sierra's 107-grain MatchKing requires a faster twist; at least an 8-inch to stabilize them on a long trip to the target, but it's a fine choice for even out to 1000 yards. In slower-twist rifles, like the 12 inches of the old-designation 244 Remington, it's tough to beat something in the 75-grain range. The 12 twist will handle most bullets up to 90 grains, and is fairly reasonable even for bullets as light as 55 grains, something I can't say about the later 9 twist.
With some of the better hunting bullets of today, there probably wouldn't be a nickel's worth of difference between 90 and 100 grains for deer. Certainly, there are better 90-grain hunting bullets available now than anyone could have imagined in 1955. Still, that probably wouldn't have helped the 244. It was the lack of a choice of good rifles for various purposes, along with an absence of the kind of advertising needed to inspire potential customers. Remington, are you reading this? Would it really cost so much to keep a couple of 6mm offerings in the Model 700 lineup? Would it really be that hard to include a listing that promotes various cartridges on your web site? Do you really not care if this fine cartridge goes away?