New 6X Cartridge

[RifleMaster]

All,

Just wondering if data is becoming available on the new cartridges like the 6X.

In the last 10 years or so, bullet designs have improved/advanced faster than cartridge design. In addition, these improved bullets have become more readily available in several new calibers. In the last, many Wildcatters simply swagged up or down existing cases to launch the new improved BC bullets (VLD's), i.e., like the 6.5-284, 6.5-08, 7mm-08.

Although I haven't closely followed these developments, I'm aware of four new cartridges that have been developed. The design intent is to develop a cartridge that optimizes case capacity with the excellent new powders that are currently available. The goal is to optimize the launch to exploit the new higher BC bullets that are available. One major goal is to give heavy bullets enough speed to exploit their long range potential while minimizing quick throat erosion. And, of course to provide a light recoil to inhance the shooter's preformance.

Tubb won this year's National HP Championship with this new 6X cartridge.

With my load development for my TBA M40A1 close to completion, I need a new project! I better start now with a nice Christmas gift for my Wife! http://www.socnetcentral.com/ubboard/wink.gif

Keep Holding'em Hard!

Carl

[Pat Murphy]

Carl,
Not familiar with the 6x unless its the same as the 6x250 that all the HP shooters are going to.

They are using the fast twist barrels and necking the 22-250s up to shoot the 105VLD 6MM bullets and they really fly and are deadly accurate with pretty good barrel life and hardly any recoil.

I have been thinking about one for a future project. I love the 6.5s and shoot the 260s and 6.5x284s now but am always looking for something new. Between my son and I we walked away from the D&L shoot with gift certificates for 3 barrels, Krieger, Pac Nor, and half off on a Shilen. We already have the fist two back in the 6.5s but maybe we need a new 6MM barrel too(HA).

Let me know if the 6x is the same or if its something different. Thanks!!

[RifleMaster]

Hi Pat!

The 6X (6mm-250) is a .250 Savage case with a .243 neck. It is formed by expanding the neck on a new .22-250 cartridge case. This case is 0.130 inch shorter than a .243 Win.

I know some local top HP shooters (US Palma Team Members) that started developing a similar cartridge in 1995. They have been competing with it at Camp Pendleton for several years. I think it is also based on the .250 Savage case. Later today, I may call up Dennis F. and Dave M. and get an update.

I still prefer alittle heavier bullets, i.e., 6.5mm and 7mm. I prefer a good balance of mass and velocity! We all know higher velocities translate into shorter barrel life (throat erosion).

Carl

[Pat Murphy]

Carl,
I am with you on that, thats why I am sticking with the 6.5s for now. I am going to keep my eye on its development though. I can't seem to get any solid answers on what the expected barrel life is out of the 6x250s. I wouldn't think it would be much more than the 3000 to maybe 4000rds. if you didn't get them hot. I am looking at possibly going 3000 with my 6.5x284 but other than a couple of matches I have been real careful about getting it hot also.

Have you heard any velocity figures?? I have heard around the 3200fps range. I don't recall what I used when I ran my data to check on its ballistics but I believe, as I recall, it would have been close to the 6.5x284 which is pretty damn good.

My gunsmith built one for long range coyotes and loves it. Says there deadly accurate!! I would bet it would be a sweet shooting rifle, but then I don't know why it would be much different than a .243 either.

[Pat Murphy]

Carl,
Just a thought that popped into my head, wouldn't this round be nearly the same as the old 6MM International only with a different twist?? I think the Navy team tried it in competition years back.

[USMCSNIPERONE]

Hmmmm? Anyway I could sneak that into a Service rifle? http://www.socnetcentral.com/ubboard/biggrin.gif How about a .223 Improved? HeHeHe! I know, I know, Cheater!!!

Semper Fi Sniperone

[EchoFiveMike]

3200fps with what bullet? I've seen guys claim 2900'ish with 107 Sierras from a 26 inch tube. Figure that the muzzle pressure is fairly low, so maybe squeeze another 80-100fps out with a 30inch tube, and that's a strong maybe considering you don't have that much propellant to work with. Seems like somebody just had to have something different. I'll stick with 260's and 7-08's for work when the target needs to go down when I shoot him. 6mm is heading down towards the area where bullets don't have enough mass to defeat glass and light cover and stuff. I've been meaning to do some testing on glass, but haven't been able to motivate my lazy ass out to make brackets to support the glass. Semper Fidelis...Ken M

[Pat Murphy]

EchoFiveMike..
I am sure thats what they were claiming when we were having the discussion on it. Its like a 243 will max out at 3000fps with a 100gr bullet but a 260 will push a 120 that fast or a 100gr bullet over 3200fps. Same case and all just doesn't make since sometimes to me either.

There would be no advantage at all, in my book, to shooting a 105 at only 2900fps. compared to the others.

[EchoFiveMike]

Pat, if they're claiming 3200fps with a 107 Sierra or similar Berger from a 6X, then they are smoking crack. It has less capacity than the 243, so there is no way they are getting any more velocity out of it. S/F...Ken M

[RifleMaster]

Hi Pat and Ken!

Mid T. told me awhile back that they were pushing their 6.5 140gr bullets between 3100 and 3200 fps from their 6.5-284's. I think Pat is correct in that barrel life at this velocity is about 2,000 to 2500 rounds. Actually the barrel life will depend on the accuracy you need to retain.

Tubb's 6X is the earlier International. My friend Dave M. told me that their new cartridge is also based on the 250 Savage but they are shooting 6.5mm bullets. He did not have any current MV's. I agree with Ken that the 22-250 or 250 Savage case doesn't have the capacity to obtain competitive speeds with the 6mm or 6.5mm bullets. Just my opinion!

Keep Holding'em Hard!

Carl

[Pat Murphy]

I had a friend e.mail me the name of a gunsmith who builds the 6x250s and is suppose to be the man in the know on them so I will give him a call later on and see what he has to say about the velocity and barrel life on them.

I have to order a barrel in the next couple of weeks or I loose it so I may just order one in a 6MM if it is capable of the 3200fps range. I think it would make a neat tactical rifle. Besides you always need a project,right???

[Pat Murphy]

Ken & Carl,
I just got off the phone with a smith who builds and shoots them. Ken is right, he said the 2900 to 3000fps is what I would be looking at. Barrel life is still questionable since he hasn't shot one out or talked to anyone who has. He's guessing around 3500rds or in that neighborhood.

He states that they kick butt on the 308s but probably wouldn't be any improvment over the 6.5s. Said he shot some 600yd matches against the 308s and it was no contest. Recoil is very mild and wind drift is much better with great accuracy. I think I will still stick with my 6.5s for now though.

[RifleMaster]

Pat,

What did you decide to build with those two new barrels?

I'm still thinking about building a 6.5mm X 284 or a 7MM SWM long range rifle. I have a 7mm in 1/7.8 twist barrel.

Carl