.22 CHeetah. I came across a firend the other day that had a rifle made up in .22 CHeetah fro pronghorns and Muleys.

I know that there's the MKI and MKII, the former has a 40 degree shoulder and the latter has a 28 Degree shoulder. I know that the .243 Winchester brass is the preferred brass for making the .22 CHeetah. That's just about the end of my knowledge.

The short barrel life expectancy and marginal ballistics would lead me to look for something more practical, the .243, if for deer.

DOesn't the Cheetah use small rifle primers, so it is basically a 22-308 BR. In the most technical sense, 22-243 is not 22 Cheetah.

Stupid fast, and of course nasty on pipes as are all super fast, terribly inefficient, and ridiculously fun chamberings. But if was a hunting gun, and assuming you could work up a load in say...oh, I don't know...say... 300 shots ;), you would still have 500+ to smoke things with. Prolly need a new pipe in 30 years.

It's a barrel eater!!!!

And the barrel eater comment as well. BOLOGNA!

I have had one of each. 9 times out of ten when a big 224 is thought to be burned out it is copper or, of late, hard powder fouling. Removed with Black Powder Gel and other compounds. Derby, you had the stuff in your post right on. It is a fun and flat shootin cartridge and I will build another soon or a 22/6mmAI. Speed kills.

Much better said. Right on RE primers etc but I got tired of forming down 308BR brass and neck turning them and just went with 243 brass necked down then used, large primers and all. If anyone here is taking 300 rounds to work up a load then they are probably starting out with a dog of a barrel at the outset. Especially on a deer and antelope rifle the barrel life would be plenty long and, like you said a REALLY fun cartridge to play with. Everyone really ought tohave one.

The goal of all true rifle looneys should be to burn out as many barrels as possible in ones lifetime.

The CHeetah sounds like a bunch of fun to me.

Buy the reamer , order two barrels and shoot the hell out of it.

22-6mm AI sounds like fun, after I get bored with my latest project. I'm going with a 338 Ultra Mag necked down to 6.5 with a 40 degree shoulder, that should work wonders on a Benchmark barrel. I'll find out.

Another name for that 22/6mmAI is the 224TTH or Texas Trophy Hunter. A nearby gunsmith uses one with a fast twist Lilja 3 groove barrel to win the regional 1,000 yard benchrest matches.

Luvin the sound of that 6.5/338RUM! Do report on it when you get it all up.

I've a couple Mach One's and like the LR primer route and form with virgin 243 after turning. It's a pain in the ass,compared to say the 22-250AI which I much prefer.

An 8" twist 22-250AI is where it's at and if wanting more,the 243AI is the answer due to better BC's. The 6mm/6mmAI in any guise,is a heavy concession in s/a due to case length.

I shoot them all.

I'm hijacking....but only for a moment....

I have a ABS wrapped BenchMark that will be here in a month or so that I will have punched into 6.5 WSM. This will be #2 in that chambering for me. I built the first one on a LA and I am going to try this one on a short. I know, I know, don't say it. I am building a hunting rifle. Anyway, 6.5 RUM would probably let you get 140's up to almost 3500, 3400 should be no problem given enough tube. The 6.5 WSM on a LA will get you to 3200ish with a 27" barrel. That would be a LR phenom....can you imagine Berger 140s at 3400+?

I thought TTH was 22-6mm without the improved part. I might be mistaken...it happens quite often .

dd

http://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/5592787/1

Your friend say what bullet he was usuing?

dave

Only someone thats never used one, would say that.


dave

You could be right, I have not built one. IF it is the un AI'ed 6mm case then I will have to think up another name for the AI'ed version because I HATE trimming cases and will do the AI in a heartbeat.

Fast twist big capacity CF 224s are a blast. I am still pimping 22x47s but am thinking about going a little crazier one of these days. If the bullet companies ever cooperate and build a 90-100 gr bullet that is robust enough for the rigors and has a off da charts BC, I am gonna do something crazy.

Thanks Dave, I'll put that link in my favorites when I get home.

So, out of a 700 BDL, the MKII with the 28% shoulder better for feeding out of a magazine?

dd
I alway ran my as a single shot.
The 40 degree shoulder thing can be bested in the feeding department by the 28.But a good smith can do wonderful things.
Once you blow the 40 degree shoulder you can throw the trimmer away...you'll never need it.Cheetah case actually gets .003 or so, shorter on fire forming.And never grows after that.
The 243 WCF case is a good starting point.
If you read my other posts from the other thread.Theres some very good info there.
dave

Thanks Dave. Just read your other thread.

I'm just at the curious stage at this time. Don't know what I'm going to with the rifle. It's been suggested to turn the rifle into a 6MM-250 but who knows.

DD

The Cheetah is alot of work.
But as has been stated..the fun factor is always there.
You want impacts?
Get a video camera to go along with the Cheetah.
I've flipped 10 lb chucks into the air at 500.The impacts on smaller chucks are even more wild.
You ever decide you want to play I have a formula that will get one to shoot out the gate, without reinventing the wheel.


dave

Thanks Dave, I'll keep you in mind if I decide to play with the Cheetah. I saw my friends rifle the other day and it was a sweet little rife with a 24" barrel. I said to myself, hum, that might be fun.

Sharp Shooters Supply has a chamber reamer for 22-243AI with the 40 degree shoulder. I had them punch out my 26 inch varmint weight Savage 22-250.

The CHeetah requires some volume reducing forming steps, which I consider a PIA, and counter productive to my needs.

I run 243 brass into the sizer to reduce neck diameter and fire form with a 60 gr bullet at 3600 fps.

The next barrel will have a faster twist, currently it is the original Savage 14 inch. So I stick with the 60 gr Hornady spire point. H414, H4350, IMR4831, H4831, and Magnum all work well with this bullet.

From www.loaddata.com:

.224 Texas Trophy Hunter (TTH) / .22-6mm Remington Reloading Data

Following extensive experiments with the 220 Swift, 22/250 and 240 Weatherby cases, the designer settled on the 6mm Remington case as the best balance of case taper, shoulder angle, length and capacity. Necking the 6mm Remington case down to 224 (with the factory's 26-degree shoulder angle), he created a cartridge that would deliver heavier well-constructed, 70 to 80-grain 224 bullets accurately at relatively high velocities. The 6mm case provides optimum capacity for the 224 bore, brass is readily available, and standard actions and magazines require no modification other than a new barrel. Proper rifling twist for the 224 Texas Trophy Hunter is 1:8 or 1:9. Bullet construction is the key to success; it takes a stout, thick jacket, solid or bonded core bullet to hold up to the velocity potential. Stoutly constructed bullets can be driven in excess of 3,500 fps. Dies are available from Redding; Nosler recently endorsed its 22-caliber 60-grain Partition bullet for whitetail deer hunting. (Cartridges of the World 10th and 11th Edition)
Be Alert: Publisher cannot be responsible for errors in published load data.
Wt. Bullet Powder Manufacturer Powder Charge Velocity (FPS)
55 Trophy Bonded Hodgdon H-4831 46.5 3,840
60 Nosler Partition Hodgdon H-4831 46.0 3,780
79 Lost River Vihtavuori VV-N165 45.0 3,520
75 Hornady A-Max Winchester Win Mag Rifle 47.0 3,780

What does that actually mean?

dave

If you build it on a Savage action or a Remington 700 (or better a single shot XR-100 or 40X if one can be found) with a Remington barrel nut and pinned recoil lug, you can swap out the barrels yourself. The Savage allows swapping bolt heads across case families inexpensively, so different cartridges can be experimented with. The CHeeta shouldn't erode barrels any worse than any other overbore .224 with today's powder choices.

There is loading data for the .22 Cheeta Mark II on the Hodgdon loading data site.

To my pea brain I don't see what the CHeeta will do that a .22-250, .220 Swift (especially the Ackley Improved versions with better brass life) or the .223 WSSM will not do without all the hassle. The .22-250 and Swift having the advantage of fitting the .308 Winchester's bolt face.

I don't use .224 calibers for long range varmints, preferring the .243 WSSM. While that is my thing, I still have two .22-250's and I'm building another in the Ackley chambering, one .220 Swift and a couple of .223 Remingtons. The .220 CHeeta would be a good choice for a foray into wildcat cartridges, with the learning experience being a side benefit.

Compare the brass length of 1.986 inches for the CHeetah Mk I vs 2.015 in for the 308, or 2.035 in for the 243.

In the Mk I version of the cartridge, The neck/shoulder juncture is actually moved back and the brass is trimmed, which reduces capacity of the finished cartridge when compared to the AI version of the cartridge. Carmichael's goal was maximum accuracy by bench rest standards, not maximum powder capacity.

In the Mk II version, the brass is left full length. But the 28 degree shoulder does not allow the case as much volume as the AI 40 degree shoulder.

It is much simpler to just neck down the 243 case. Then fire form to the AI dimensions, and have a bit more volume in the case when finished.

The CHeetah Mk I measures 1.647 inches from base to shoulder, the Mk II measures 1.605 inches from base to shoulder. My actual fireformed 22-243AI cartridge measures 1.69 inches from base to shoulder.


MK I




MK II


22-243AI

Compelling. I shoot them all and the CHeetah is easy to pass on and the 22-250AI is where it's at. Much prefer the 223AI,but that is an issue separate. The Swift and Rocket are junk,as are Mouser based goat [bleep].



If/when the fast twist 22-250AI is leaving one shy of a good time,it's time for the 243AI.

So, if I'm reading you right the MKI is the improved version and the MKII is the standard version, correct?

No real reason the MKII couldn't be made from .308BR brass, correct?

If one uses .243 brass to make the MKII than what one has is really .22-243 NOT a .22 CHeetah, correct?

Mk I and Mk II are both "improved" as the original 308 or 243 case has a 20 degree shoulder and both CHeetahs are sharper than that.

Either form of the CHeetah may be derived from 243 brass more easily than from 308BR. Except by definition the CHeetah has a small rifle primer pocket and that can only be acquired through use of 308BR brass.

A 22-243 case would measure 1.560 inches to the shoulder and 2.045 inches overall with a 20 degree shoulder.

Yes the differences are subtle and mostly insignificant, except when ordering chambering reamers, headspace gauges, and resizing dies.

Our friend made a very valid point re 22-250AI. Any case larger than that burns a lot more powder for very little velocity gain.

I knew that very well and had my barrel chambered for the 22-243AI. Nobody ever said this stuff had to make sense.

Might be a pun there.

For us, the unwashed masses, can you identify the members of that lineup?

I'll take a stab at it...

Hornet AI, 223AI, 22-250AI, 243AI.

They all look .22 to me...

K Hornet, 223AI, 22-250AI, 22 Cheetah

I came across this on stevespages.com

http://stevespages.com/jpg/cd22243.jpg

It just says .22-243. It has a 30o shoulder. Is it a Middlestead?

What do you think of a .22-250 with a 30o shoulder?

Based on written descriptions, which I have read, of the 'Middlestead, I would answer "Yes". The drawing you referenced appears to be it.

A 30 degree 22-250? Not for me.

I would go Ackley or leave it as Remington built it. The greatest advantage of the improved cartridge is that the 40 degree shoulder eliminates brass flow and longer or thickened necks, thus eliminating the need for trimming or turning of case necks.

I do not have the experience with wildcats that Paul, or Big Stick, or Steelhead have. I only have two AI cartridges. But I lose very few cases when Fireforming to the 40 degree shoulder of the 30-06AI or the 22-243AI. Just use brand new brass.

If I had a 22-250AI, I would buy 250 savage brass and neck it down to 22 for a good chamber fit when fireforming, to insure proper headspace.

One should be able to fire factory 22-250 cartridges in a properly built Ackley chamber, but I would go the 250 route anyway.

I believe you are correct.



A properly chambered AI rifle will crush fit on a standard case. And you cannot beat Lapua 22-250 brass.

I kinda figured a 30o shoulder wasn't worth it on a .22-250.

Thanks.

The fly in that ointment is the spotty quality of 250 Savage brass. It hasn't been as good as generally available 22-250, and it isn't going to be on the same planet as Lapua 22-250.

Using 250 Savage brass is a backwards approach.

I have been known to run a 243 expander into my 22-250's and neck them back down. But that was to put off doing a rechamber on a rifle which had a "generous chamber".