22 Cheetah MK 1

[jmbn]

A cousin just bought a rifle from a neighbor who didn't seem to know too much about it, called a 22 Cheetah Mk 1.

I did a search on this forum and it seems like it's made on a 243 case, maybe with a sharper shoulder. Does anyone have any specific info on this cartridge? How does it differ from a 243 AI case?

We would also be curious as to who the developer is. What is the Cheetah Mk 2?

Thanks very much for your help.

jmbn

 

[Varmint Hunter]

The 22 Cheetah was developed by Jim Carmichel, shooting editor of Outdoor Life magazine and Fred Huntington of RCBS fame. It appears to have originated in the late 1970's. The cartridge is essentially a full length Remington 308 BR case, with a smaller primer pocket, necked down to 22 caliber, but with the shoulder moved forward. What you end up with is a variation of the 308 Winchester necked down to 22, but using a special match case. This is not exactly new because there are in existence several slightly different versions made by necking the 243 Winchester case down, and these date back to the early 1960's. However, the 22 Cheetah is an original with regard to the 308 BR case and its smaller rifle primer pocket.

General Comments:

The major difference between the 22 Cheetah and its predecessors are the use of the lighter, more uniform BR case, blown out 40 degree shoulder angle and short neck. In other words, the case has been designed to benchrest specifications. It also has a greater powder capacity than any of the older versions. There are actually two case types, the MKI with a 40 degree shoulder angle and the MKII with the original 28 degree shoulder. The 22 Cheetah is somewhat more powerful than the 220 Swift, but ballistics were measured from a 27 inch barrel. The cartridge has proven to be superbly accurate and a very effective 300 yard varmint cartridge

Hi-jacked this off the web, hope it answers your questions.

VH

 

[jmbn]

Thanks, VH. That's about what I thought. I'll bet it's a barrel burner.

Necking the case down from 30 cal seems like a serious operation, probably in several stages with maybe more than one neck-turning. For us ordinary people, maybe it would be easiest to form cases from a 243, using the shoulder left on the neck for initial headspacing.

Thanks again for your help.

 

[cejamania]

Not a barrel burner if cleaned properly. Must push a brush through after every ten shots. Carmichael and Huntington took on the challenge to devise the fastest most accurate cartridge they could. The result the .22 Cheetah Mk I. They did not shoot out the barrel on they're creation. There are six forming steps with the last being a fire forming. I have been shooting mine for 20 yrs. I use a Remington 52 gr. Hollow Point Flat Based bullet. Behind it is 43 1/2 grs of 4064 IMR Powder. The cases are the .308 Remington Bench Rest Cases with the small Primer hole. It's a life taker. A meat gun. Chrono'd at 4480 fps. Way more beefy that the Bee's. Get it going you wont be sorry.....

 

[Kevin Thomas]

jmbn.

If you want to get back to more or less the original version of the 22 CHeetah, there's always the new Lapua 308 Palma cases. Match spec, and are produced with the small primer pockets just like the original Remington 308 UBR cases Jim used in developing this cartridge.

Incidentally, the case is normally designated as the 22 CHeetah, with the C and H both being capitalized; they denote the two developers, Carmichael and Huntington. Neat round, and a high powered performer if there ever was one.

 

[paphil]

What is the twist rate ? Would shoot pretty far with 1-8 twist and 75 A-max!!

 

[Kevin Thomas]

Original twist rate was a 1x14" or 1x16" as I recall. It was set up around 50-52 grain bullets.

The round is a potential barrel burner even with these bullets, but it'd be ugly with 75-80 grain bullets. Wouldn't give it much more than 800-900 rounds before accuracy started to sour.

 

[cejamania]

It was a 1 x 16 twist. My barrel is a 26 inch Stainless Douglas Supreme. The rifle is so accurate you stop wasting missed shots bringing your total shots per hunt down. The barrel is screwed into a Remington model 700 action with a 40 x trigger. The stock is a Brown Precision Varmint with a palm swell. The action is glued in and glass bedded and the barrel free floated. It is a single shot and I have a Unertl 20 x 1 1/2" Target on top. Chucks are shot in the head at 350 yrds. Extra fine cross hairs are required though. I let a Remington .243 Varmint Special with a 12 x Lyman Super Target Spot and a Varmint Special in 25-06 with a 16 x 2" Unertl and $100.00 go for it and 200 bullets, cases and primers. I've never been sorry. I'm telling you it's like shooting a laser.

 

[cejamania]

Ballistics tell the story. An 1 1/2" high and an 1 1/2" low from muzzle to 400 yrs. Now thats flat....

 

[Dusty50x]

A cousin just bought a rifle from a neighbor who didn't seem to know too much about it, called a 22 Cheetah Mk 1.

I did a search on this forum and it seems like it's made on a 243 case, maybe with a sharper shoulder. Does anyone have any specific info on this cartridge? How does it differ from a 243 AI case?

We would also be curious as to who the developer is. What is the Cheetah Mk 2?

Thanks very much for your help.

jmbn

Well l have been around one quite a bit and all l can say it never ceases to amaze me..You every see a fox squirrel hit at a 105 yards in a tree with one..Well l have and it hit the little barking devil between the come the rear end and he never left the branch.That was one we never got to eat..Total devastation on Coyotes and fox..Not much left of red fox if hit wrong but coyotes it doesn't bother..

 

[Trickymissfit]

Not a barrel burner if cleaned properly. Must push a brush through after every ten shots. Carmichael and Huntington took on the challenge to devise the fastest most accurate cartridge they could. The result the .22 Cheetah Mk I. They did not shoot out the barrel on they're creation. There are six forming steps with the last being a fire forming. I have been shooting mine for 20 yrs. I use a Remington 52 gr. Hollow Point Flat Based bullet. Behind it is 43 1/2 grs of 4064 IMR Powder. The cases are the .308 Remington Bench Rest Cases with the small Primer hole. It's a life taker. A meat gun. Chrono'd at 4480 fps. Way more beefy that the Bee's. Get it going you wont be sorry.....

Carmichael admitted it was a four to five hundred round case design many times. Hogdon list the MK.II as 4070fps with a 50 grain bullet, and the MK.II was a little faster. 42 grains of IMR 4064 with a 50 grain bullet is considered max, and that's also about 4060fps using a 27" 1:16 twist barrel. Would be a little slower with a typical 1:14 twist. It otherwords not a lot better than a 22-250AI, .220 Jaybird, and much slower than a .224 Vias.
gary

 

[Rich Coyle]

I had a .22-243 AI that achieved 4,350 fps with fifty-five Noslers. One other poster hit over 4,400 using 50 grainers. The loading at the sights seems conservative.

 

[Trickymissfit]

I had a .22-243 AI that achieved 4,350 fps with fifty-five Noslers. One other poster hit over 4,400 using 50 grainers. The loading at the sights seems conservative.

Hogdon is the only manual with data that I know of, and unlike Hornaday and Sierra is known to be pretty hot. I wouldn't always say they are 100% loads everytime, but for sure hotter than Hornaday. Still we're not talking 100fps, but 300fps. One has to wonder if they are shoot in the 70K + psi range. A look in the Hornaday manual with the .22-6mm (an even bigger case) will show 3900fps with a 55 grain bullet. Seems a little conservative to me, and I would expect something close to 4200fps (that's 300fps!)
gary

 

[panama]

Built(3) 22-243 (2) on 1-9 twist (1) on 1-12 1-9 my own shoots 77 smk @ 3700 26.5 bbl. it is a lazer and bucks the wind pretty good, 1-12 on rem 700 did not like any bullet over 55gr. the other 1-9 on 600 mohowk had a 25"bbl this one has killed over a doz. deer and 2 cow elk since its build in 99 and still shooting good, it shot the 77's 3570. this was a paul middlestead desig. came about 1964. all BO CLERKE bbls he told me make the cycl. about 3" long when the throat gets bad take off a thread rechamber no need to rebbl.so far have not had to do so just don't run it past 4k