If loaded in barrels of the same twist and length and loaded to the same pressure with a powder suitable for all of them...

Would the velocities of the 221 Rem, 222 Rem, 223 Rem, and the 222 Rem Mag all graphically line up on a curve with powder capacity on the horizontal axis and velocity on the verticle axis ?

All the published data have the 222 Rem and the 222 Rem Mag unnecessarily loaded to lighter pressures than their 221 and 223 cousins.

The Remington 700 actions for all are the same. Barrel steel is the same.

And if the brass in the cases are different (don't believe they are), they could be case formed from the same basic brass or from 204 Ruger which is loaded to high pressure.

I don't have a .221, but do have a .222, .223, and .222 Magnum in identical Sako sporters. I load all of them to approximately the same pressure. The ballistic difference in them is minimal. The .222 will throw a 50 grain bullet at about the same speed as the two larger cases will shoot a 55 grain bullet. The difference in the .223 and the .222 Magnum is less than the difference in two barrels and chambers.

I've recently acquired an addtional .223 Sako sporter and .222 Magnum Sako HB. Their performance tends to confirm the observations with the other three guns.

I have no idea why the .222 is consistently listed at being loaded to lower pressures than the .222 Magnum, which itself is usually loaded a bit lighter than the .223. Such are the vagaries of the SAAMI system. But then that's why we visit on a forum call "Accurate Reloading" -- because we load 'em the way we want 'em (for better or worse).

Hmm now a 223 verticalzontal magnum

the reason the 222 and 222 mag. were load to
less P.S.I. is that the Rem.722 had extraction
problems at over 48000 psi with the small case
head.hope this info is of some small help...
Jon D.

Don't remember if the 223 Rem came after the introduction of the 700.

But if the 722 extractor is the issue, then the 700 versions should work fine with the same pressures as the 17, 204, 221, and 223.

quote:

Originally posted by Jon D:
the reason the 222 and 222 mag. were load to
less P.S.I. is that the Rem.722 had extraction
problems at over 48000 psi with the small case
head.hope this info is of some small help...
Jon D.

I'm somewhat doubtful that the sometimes problematic extractor on the 722 had anything to do with the SAAMI specs. The 722 extractor was infamous for breaking, but that had nothing to do with how it worked as long as it held together. Admittedly, the 721/722 extractor was relatively weak, but pressures in the 50k range will not expand case heads, so the extraction is not an issue.

The .222 Magnum has always been loaded to a bit higher pressure than the .222 for reasons that are unclear. The reason the .223 specs are higher still is that the military has always used about 55,000 c.u.p. as their standard and specs cases heavy enough to tolerate that pressure without excessive case head expansion.

All commercial .222, .222 Magnum, and .223 cases are identical in the case head specs, so it is reasonable that they all can be loaded to the same pressures (given similar rifle actions).

Parenthetically, I have found that loading charges of powder that modestly exceed the "maximum" recommendations of most reference sources in these small cartridges does not result in signs of excessive chamber pressure. Case life with loads of 5% or more over "maximum" do not result in shortened case life. With that said, the purpose of these rounds does not argue in favor of stretching the last bit of velocity from them (get a .22-250 if you want that), so I load them somewhat conservatively, anyway.

Stonecreek
With the 722 l don't know for sure what caused
the hard extraction l do know it did. Most BR
shooters of the day would run HOT loads as they
would group better at 200 and some varmenters
done the same.when 322 powder came out most
shooters found it shot best at two grains over
max in the 222 but brass would not last long.
l have seen bolts locked up and cases had to be
turned out.never seen this with the 700 action
or a custom action.some of the older BR shooters
maybe would come in and help on this.
Jon D.

Both the 222 Rem Mag and the 223 Rem originated as military experimentals. That may partially account for their higher pressures. The 222 Rem was a commercial cartridge from the get-go but the basic case was used as the basis for both the 222 Rem Mag and 223 Rem, and several other military experimentals too.

Ray

quote:

Originally posted by Cheechako:
Both the 222 Rem Mag and the 223 Rem originated as military experimentals. That may partially account for their higher pressures. The 222 Rem was a commercial cartridge from the get-go but the basic case was used as the basis for both the 222 Rem Mag and 223 Rem, and several other military experimentals too.

Ray

Correct you are! Had it not been for the slightly too-short magazine and receiver of Stoner's original design (which became the AR-15/M-16), the .222 Magnum would have been the 5.56 Nato and the .223 would never have seen the light of day. The .223 was a result of the need to slightly shorten the LOA of the round to fit in the new gun.

It seems that Mike Walker of Remington was "tuned in" to the military development of a .224" military round and when the military designers produced what we now call the .222 Magnum he assumed it would be the coming thing and introduced it as a commercial round, beating the (never to happen) introduction of the military round to market. It is a testiment to Remington's marketing (and the excellent benchrest qualities of the .222 Magnum) that it ever gained enough of a market foothold to survive when the military junked it in favor of the slightly shorter .223.

Now for a real cartridge trivia test: Who chambered the .222 Magnum in a factory rifle? As far as I can recall, it would be limited to Remington, Sako, and Browning; I think that Krico and the Herter/BSA might also have been offered. Can anyone name any others?

quote:

Now for a real cartridge trivia test: Who chambered the .222 Magnum in a factory rifle? As far as I can recall, it would be limited to Remington, Sako, and Browning; I think that Krico and the Herter/BSA might also have been offered. Can anyone name any others?

In the early 1980s, the original Kimber rifle was offered in the 222 Remington Magnum in their Model 84.

Had a complete collection of their lefties including 22 Hornet and 17 Remington.

Thanks for the reminder, Hammer, I think your right about that.

Remington made the 722 and both the 700 and the 40x in .222 Magnum, but I count tham all as a single gun since they were all derived from a common action. I guess the 725 was also chambered in the Magnum, but I don't think I've ever seen one.