Is there a 6mm-250 or 6mm-250 AI

J

Jim in MI

New member
Gentlemen,

I know little about wildcatting and nothing about calculating eficiency of a case, ect...

...but when I look at my 6mm bullets and my 22-250 cases they just look like they "go" together.

It takes quite a while at the range to work up loads for my .243, as I'm always stopping for the barrel to cool, and I thought a 6mm-250 would be kind of neat.

Is this how guys end up with empty pockets, going around thinking "It would be really neat if I could just...."

Thanks
 
Jim in MI,
Since the .22-.250 is basically just a necked down .250 Savage, it should be fairly easy for a good Smith to fix you right up with a 6mm-.250. I think it would make a dandy coyote whacker. /ubbthreads/images/graemlins/smile.gif
 
Since you already have a 243 you might as well use it. Just load it down with the minimum suggested loads. Powders like 3031 and 4759 are good for this. So are others that burn about like 4985.

For a new barrel made for range specific shooting the 6mm/250 has some advocates.

I have used the 6mm International for years for 200 yd position shooting. Today the 6mm Br would be a better choice.

http://www.6mmbr.com/index.html
 
i know you can find a lot of info on the 6-250 on 6mmbr.com or something like that.. they shoot it a lot with fast twist barrels in long range competitions....! i think its fairly popular...fairly close to David Tubbs 6xc ...
Brien
 
Contact David Bagnall at 432/263-7703. He has been building rifles in this cartridge for several years. He can give you more info than probably anyone, it's one of his pet rounds.
 
Some years back - like 2000 or 2002 - Precision Shooter ran an article about the .22-250 AI necked up to 6mm. This caught my attention as I have the .22-250 AI and think that this would make a nice alternative when my current barrel wears out (which is coming up fast). I can just get new dies, neck up my existing cases, and start stuffing in 87-gr. VMaxes for the long windy shots.

Compared to the .243, the .22-250 AI has a shorter shoulder, but the case bodies are quite close in size. But, as long as you have a .243, you might as well spare yourself the considerable expense of fooling around with custom barrels and wildcat rounds if you can help it.

"Is this how guys end up with empty pockets, going around thinking "It would be really neat if I could just...." "
Yes you are quite right.
;-)
 
The 6mm-250 holds about 41.5gr of water, right in the middle of the 243 and 6mmBR. You are better off necking up the 22-250 than necking down the 250. Lots more 22-250 brass around and the 22-250 also has a semi-improved 28degree shoulder., compared to the 26degree shoulder of the 250 savage. Expect 3200-3400fps with 70gr bullets and max-load 95gr bullets around 3000fps. In a good rifle this can be a very accurate cartridge, and recoil is pleasant. Look up loads for the 6mm International and use them as a basis to load up from there, it is a slightly smaller cartridge. Have fun--2MG
 
If I remember correctly, the 6mm International was ceated by running a 6mm Remington reamer just part way into the chamber. When you fired a necked up .22-.250 case in the chamber, it blew the case out to what amounts to a 6mm Remington "short". It seems to me that the 6mm International would have more powder capacity than a standard 6mm-.250. That being the case, I would not start loading a 6mm-.250 with suggested loads for the 6mm International.
 
The 6mm Remington International was developed in the late 1950's for 300 meter International target shooting. It was put aside and the .308 Win was favored. The cartridge also missed the cut in the benchrest rules for the hunter class and therefore has been little used.

The older Sierra manuals have loads and nominal dimensions for the cartridge. It's formed from 250 Savage cases with two form dies by pushing the shoulder back a tenth of an inch. The shoulder angle is about the same with 26 degrees for the 6mm Intl. and 26, 30 min. for the 250 Sav.

The dimension from the base to the neck/shoulder junction it's 1.5398" for the 6mm Intl. and 1.637" for the 250 Sav.

A maximum load in the 6mm Intl. with the 75 gr bullet could be 33 grs of 3031 for 3300 fps from a 20" bbl. I loaded 30.8 grs in a 40X with a 27.5" bbl. for 200 yd position competition. My barrels are twisted 1-10".

The case has the same body taper as the orginal 250 Sav. In appearance it has a very long neck.

The 300 meter Olympic competition is no more. The 6mm Intl. is now obsolete. Today the 6mm Br is shot with good effect from qt barrels out to 600 yds and beyond with VLD bullets that we did not have back in the 60's.
 
300 meter Olympic competition is on hold(has not officially been dropped, just not done lately) but 300 meter World Cup, World Championship, and Pan American Games competition is very much alive.

A friend of mine won a World Championship 300 meter match in Spain 10-12 years ago. Competitive shooting is a big deal in Spain. 2 million spectators turned out for the match and when he won they carried him on their shoulders through the streets for a long ways. It was a bigger deal than being the best matador of the year.

Quite a contrast to the US where even the Olympic shooters rarely get any notice at all. Listening to the US media you would never guess that shooting is the biggest Olympic sport after field and track.

I think the most competitive matches I ever entered were the 300 meter matches at Quantico MCB. They drew people from all over the world.

Jack
 
Savage 99 well said. Rich Cronk--the 6mm Int. has slightly less powder capacity because the shoulder is pushed back as you can see, and remains at a 26 degree angle. The 22-250 case has a farther forward shoulder and a 28degree angle, hence, more powder capacity. And is a perfect basis for starting load comparisons to the 6mm-250--2MG
 
2muchgun,
Turns out that we are BOTH correct. /ubbthreads/images/graemlins/smile.gif The 6mm International that my friend made was built like the bench resters did it before the 6mm International was standardized. The reamer was standard 6mm Remington, and was only ran part way in. When a .250 Savage case is necked to 6mm and fired in the new chamber, you end up with a case with MORE powder capacity than standard .22-.250. I guess that version would actually be a wildcat. A case full of WW760 behind a little 70 grainer makes those buggers scream for certain.
 
I have owned and shot the 6mm Rem Intl. since 1961 and this is the first I have heard of two versions. I suppose the moderator is always right?

I ordered a new Remington in 1961 in that cartidge and they shipped the version on the 250 then. I ordered a new barrel for it from Douglas in the 80's and they shipped the same one on the 250.

Whatever.
 
David Tubb has a 6mm verion of the 250 called the 6X. It must shoot pretty good as he has been winning High Power championships with it. I believe you might find it on the website below.

www.zediker.com
 
Savage_99,
Moderator always right? Shucks no. /ubbthreads/images/graemlins/smile.gif I talked to my old gunsmith about it and I only know how he built his version of the 6 International. My Smith could be wrong about what he told me, but it seems that the wildcat version may actually be better that the old "standard" version. I may just have him build me one so I can shoot it over my chrony. /ubbthreads/images/graemlins/smile.gif
 
Jim,
Hi there. You have a good eye for the bullet vs case thing. I'm the guy that Bob Addy was referring to in his post. We've had a good bit of experience with various .24 caliber wildcats. Most are a case of too much powder and not enough hole!!The 6-250 40° is indeed everything that you dreamed it might be. It is an ideal balance of capacity to bore.The good news is that it is so easy to chamber and load for. Just use a .243 Ackley reamer and short chamber it. This is technically a "wildcat" and not a true improved cartridge (there is no factory parent cartridge). I first started using a 22-250 case that was necked up to 6mm and ready to fireform for a headspace gauge.....you just can't get any closer than that! I use .243 starting loads reduced by 5%. Brass is simply .222-250 necked up to 6mm in one pass. The first rifle we built is 8 years old, been to 2 prairie dog wars and, and still shoots a 58gr VMax in the .2's at 4000 fps. I haven't had this load exit very many coyotes It's not hard on the brass or the barrel.
I have no idea what brass life is, because I haven't had any fail yet.
Have fun,
David
 
Quote:
Savage_99,
Moderator always right? Shucks no. /ubbthreads/images/graemlins/smile.gif I talked to my old gunsmith about it and I only know how he built his version of the 6 International. My Smith could be wrong about what he told me, but it seems that the wildcat version may actually be better that the old "standard" version. I may just have him build me one so I can shoot it over my chrony. /ubbthreads/images/graemlins/smile.gif



Ok yours is better.

I bought mine for 200 yd competition and it has been very good for that. If I need a new barrel I might go with the 6mm BR

Good luck on that project.
 
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