243 Win vs 6 Creedmoor chamber pressure.

[swimster]

Why is the maximum velocity and chamber pressure lower for a 243 Winchester than a 6mm creedmore for the same weight of bullet? On a popular load data site.. When both cases are rated at approximately the same CUP? I'm referring to 70g and 107g bullets.

 

[mauser284]

SAAMI thats why. Why do idiot gun manufactures saddle the 243Win and 25-06Rem with stupidly slow twist barrels especially when they build 6CM rifles for instance. SAAMI and ignorant consumers that will purchase what ever they push out the door!

 

[K22]

The 243 Win has maximum value as a dual-purpose hunting caliber for the one-gun hunter who hunts deer and varmints/predators. I know because this is how I started in the shooting sports in the mid 60's. This cartridge has always performed outstandingly for me as a dual-purpose hunting option.

The standard manufacturing twist of 9 1/2 to 10" twist accomplishes this purpose quite nicely. In my vast experience with this totally unappreciated cartridge this twist rate produces excellent hunting accuracy with 70 to 100 grain bullets with the proper powder selection such as IMR 4064 and IMR 4350.

 

[urbanrifleman]

I have two 10 twist 6mm blanks. If someone wants a 10 twist 243. My 10 twist 243 was a pdog killer boy.

 

[swimster]

It seems like looking at the data. They are making the Creedmore out to be some kind of super gun compared to the 243. Capable of 200 fps higher velocities with the same bullets. Thanks for the replies.

 

[swimster]

I have two 10 twist 6mm blanks. If someone wants a 10 twist 243. My 10 twist 243 was a pdog killer boy.

What contour are your 10 twist 6mm blanks ?

 

[urbanrifleman]

What contour are your 10 twist 6mm blanks ?

I haven't contoured them yet. One of them is 1.25" straight.

 

[swimster]

I assume these blanks are stress relived when manufactured. Dose contouring and or fluting affect that?

 

[Bill Norris]

It seems like looking at the data. They are making the Creedmore out to be some kind of super gun compared to the 243. Capable of 200 fps higher velocities with the same bullets. Thanks for the replies.

Yea, same as the 6.5 CM. Hornady pushed all the non-sense B S with both of these. Some of the stuff they and others tried to coax the public into believing was and still is rediculous. Personally, I have nothing against either one of the calibers but the educated and experienced shooter knows better than to believe the hogwash.

 

[AckleymanII]

243 Win, R#26 with 105s = 3150 fps+

the 6 Creed is basically a 6-22/250 AI with a 30* shoulder. The case capacity is close, with the edge going to the 243.

 

[swimster]

Thanks for the replies. Kind of what I was thinking.. Have a great holiday season.

 

[urbanrifleman]

I assume these blanks are stress relived when manufactured. Dose contouring and or fluting affect that?

No.

All barrels are contoured before use.

 

[swimster]

No.

All barrels are contoured before use.

OK thinking about rebarreling a Rem700 260 Vtr. Going to a 6mm Brx 10 twist #5 contour 24 inch suppressed for shooting 70g bullets. Night coyote gun.

 

[David Milisock]

Yea, same as the 6.5 CM. Hornady pushed all the non-sense B S with both of these. Some of the stuff they and others tried to coax the public into believing was and still is rediculous. Personally, I have nothing against either one of the calibers but the educated and experienced shooter knows better than to believe the hogwash.

Hey man I know hogwash and the marketing crap you hear about the Creedmoor cartridges isn't good enough to be hogwash! .

Are the CM cartridges good? You bet, but I'm not trashing a perfectly good 243 Winchester, 6MM Remington or 6.5 Swedish Mauser just because of the BS floating around the internet.

 

[sandwarrior]

They didn't need to rename the cartridges, just use a tighter twist. Like many "talking heads" on the internet have mentioned, it gives clear differentiation to cartridges with a tighter twist and those with standard old twists. Yes, the new cartridges can shoot farther. But, it's not because of power, instead it's because of bullet efficiency with higher BC bullets. Keep in mind the marketing is for the general shooting public, not those of us who specialize in our own shooting disciplines and KNOW what we want and what we have. Picture the classic hum-de-dumb-de-do shooter, who may go through a box a year. And he hears about these new X-Cartridges that are better in his rifle. Except he didn't get a new barrel with the tighter twist. His bullets keyhole and he never gets accuracy. That there is the problem.

By naming it a new cartridge, it'll come with the right twist. And, yes it will do better. because it's optimized for that.

The rest of us can just ignore the fairy dust stories because we'll take our old cartridges and cut new barrels for what we like with a tighter twist and optimize the cartridges for what we'll do.

As many have pointed out, no miracle dust on new cartridges. Accuracy is the precision that you assemble rifle parts that are precision made and ammunition that is precision assembled, coupled with our own application of how to precisely shoot it.

 

[Bill Norris]

They didn't need to rename the cartridges, just use a tighter twist. Like many "talking heads" on the internet have mentioned, it gives clear differentiation to cartridges with a tighter twist and those with standard old twists. Yes, the new cartridges can shoot farther. But, it's not because of power, instead it's because of bullet efficiency with higher BC bullets. Keep in mind the marketing is for the general shooting public not those of us who specialize in our own shooting disciplines and KNOW what we want and what we have. Picture the classic hum-de-dumb-de-do shooter, who may go through a box a year. And he hears about these new X-Cartridges that are better in his rifle. Except he didn't get a new barrel with the tighter twist. His bullets keyhole and he never gets accuracy. That there is the problem.

By naming it a new cartridge, it'll come with the right twist. And, yes it will do better. because it's optimized for that.

The rest of us can just ignore the fairy dust stories because we'll take our old cartridges and cut new barrels for what we like with a tighter twist and optimize the cartridges for what we'll do.

As many have pointed out, no miracle dust on new cartridges. Accuracy is the precision that you assemble rifle parts that are precision made and ammunition that is precision assembled, coupled with our own application of how to precisely shoot it.

BUT, all you have to do to get one up on the NEEDMOORS is blow the skirt up and as you mention add a tighter twist to the show. AI is where it's at. LOL.

 

[Tommie]

They didn't need to rename the cartridges, just use a tighter twist. Like many "talking heads" on the internet have mentioned, it gives clear differentiation to cartridges with a tighter twist and those with standard old twists. Yes, the new cartridges can shoot farther. But, it's not because of power, instead it's because of bullet efficiency with higher BC bullets. Keep in mind the marketing is for the general shooting public not those of us who specialize in our own shooting disciplines and KNOW what we want and what we have. Picture the classic hum-de-dumb-de-do shooter, who may go through a box a year. And he hears about these new X-Cartridges that are better in his rifle. Except he didn't get a new barrel with the tighter twist. His bullets keyhole and he never gets accuracy. That there is the problem.

By naming it a new cartridge, it'll come with the right twist. And, yes it will do better. because it's optimized for that.

The rest of us can just ignore the fairy dust stories because we'll take our old cartridges and cut new barrels for what we like with a tighter twist and optimize the cartridges for what we'll do.

As many have pointed out, no miracle dust on new cartridges. Accuracy is the precision that you assemble rifle parts that are precision made and ammunition that is precision assembled, coupled with our own application of how to precisely shoot it.

Correct. That twist situation brought about the 6.8 Westerner when the nearly identical 270 WSM already existed.

 

[XTR]

John Widden pushed/pushes 105 class 6mms at warp speed from a 243.

Kinda like a 556 will blow up a 223

 

[sandwarrior]

Correct. That twist situation brought about the 6.8 Westerner when the nearly identical 270 WSM already existed.

Yes, the problem though is someone will go to the store and pick out a .box of 270WSM that won't work in his rifle because he doesn't read the part on the box where it won't work in his rifle. He then keyholes several rounds to figure out it won't work.
The new name gives differentiation. Whereas us 'oldtimers' (read: people who are into it) choose a barrel that works with an estblished cartridge, but of a tighter twist, that works for the new bullets without a new name.

Edit: I will agree that what we see for numbers on "new" cartridges is BS! They are NOT capable of producing 200-300 fps more velocity than what we are seeing without changing the burn characteristics of the powders available to us currently.

 

[sandwarrior]

John Widden pushed/pushes 105 class 6mms at warp speed from a 243.

Kinda like a 556 will blow up a 223

A 5.56 WILL blow up a .223 Rem. But, not because of twist necessarily. More because of ability to sustain more pressure. When people understand why (how it's done), then it's easy to see.