243 Win vs. 6mm CM... Another redundant Cartridge from Hornady?

M

Meroh

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After close scrutiny it was easy to make the "redundancy" argument against the 6.5 Creed vs. 6.5 x 55 vs. 260 Remington.

After being at the range yesterday and helping a new, inexperienced member get his new Ruger .243 sighted in, I could not help but be impressed with it's accuracy potential and low recoil/comfortable shooting nature.

We have all heard how great the new 6mm CM is, so I thought I would take a closer look.

Honestly, when looking at loads for both comparing bullet weights, there appears to be no advantage for heavier loads. With very light bullets, there can be up to a 200 FPS advantage, which would be ideal for varmint shooting as these velocities are achieved with only slightly more pressure.

Have a look and see what you think...

Happy shooting!

Mark
 

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Its an easy button answer to shoot heavy match bullets (including factory) with properly cut chambers for them accurately, and the twist rate, affordibly and not going custom.

If you wanted to do the same for 243, good luck. Yes you can load them to the same performance. But you're not gonna find much 243 Win ammo that can do that, and you're likely going to have to rebarrel a 243 Win. There are more 1:8: twist rifles out there like Tikkas and Rem 700s, which is great, if you want a Tikka or Rem 700. Most ain't.

But if you do, and you like handloading anyway, and you have the mag box length to run the heavies you want...then yeah. 243 Win is every bit the equal.
 
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It's redundant. The guy who is going to buy an inexpensive rifle of the rack and expect a target rifle can get sufficient accuracy with lighter bullets. The guys who shoot enough to justify it aren't buying guns at CTC. The only missing cartridge is a 25-08 (308 necked down to 257) and a faster twist rate, and possibly a 257x39.
Then they'll have something to cheer about.
 
And if they made a buncha 243 Win heavy ammo, there would be guys who buy their rifles at CTC bringing it back constantly haha

Course, doesn't matter at all for someone who shoots handloads near exclusively anyway
 
Hitzy said:
Faster twist is the reason for 6CM.
I don't buy the efficiency case design argument, that's some voodoo magic talking #### there.
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Me neither. Besides "it gives you a shorter coal with long bullets" I don't think the case actually changes performance at all either lol

Selling the sizzle.
 
When the 243 was designed, it was tossing a completely different bullet than what you can get today. Since then bullet design has changed dramatically. 6cm is designed to throw the modern high bc bullets (long and heavy for caliber) available today without worrying about cartridge overall length. Twist rate, tighter chamber tolerance, factory match ammo etc.

That being said there is something special about a 58gr vmax doing 4k out of a 243.
 
Joel said:
Me neither. Besides "it gives you a shorter coal with long bullets" I don't think the case actually changes performance at all either lol

Selling the sizzle.
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I do think the case changes performance. All BR based cartridges shoot most loads super well. Same goes for SAUMS. They all seem to have wide nodes, and shoot most bullets very well while other cartridges are more finicky with bullets/ seating depth. Which doesn't mean they can't shoot as accurate, it will just take more time doing load dev.
 
Lakkenbak said:
I do think the case changes performance. All BR based cartridges shoot most loads super well. Same goes for SAUMS. They all seem to have wide nodes, and shoot most bullets very well while other cartridges are more finicky with bullets/ seating depth. Which doesn't mean they can't shoot as accurate, it will just take more time doing load dev.
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Ah, got ya! Defer to your experience on that one. Have heard "its easier and more forgiving to load for" but didn't know the specifics, controlled for individual rifles, components etc
 
calgarycowboy said:
When the 243 was designed, it was tossing a completely different bullet than what you can get today. Since then bullet design has changed dramatically. 6cm is designed to throw the modern high bc bullets (long and heavy for caliber) available today without worrying about cartridge overall length. Twist rate, tighter chamber tolerance, factory match ammo etc.

That being said there is something special about a 58gr vmax doing 4k out of a 243.
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6 cm is designed to run those longer bullets through AR type mags, I believe. One of my 243's was a Win 70, that a PO had removed the mag box spacer out of. Even with the heaviest bullets available at the time, 107 gr and 108 gr, I ran out of neck before I could get them close to mag length, in that rfile. Twist was only 1-10 though it did pretty well with those weights. My 6 Rem's with a 1-9 twist does better. I may rebarrel one of them with a faster twist barrel throated for 110 and 115 gr bullets when the original barrel loses its edge. I cam see the advantage of a 6 cm if you don't reload. Not so much if you do. - dan
 
some of the same arguements were heard yago when 243 Win vs 6mm Rem debate was on

its not just about the new cartridge alone, the platform has to be part of the package, its all part of the newer longrange mind set
as well as the wildly increased interest in PRS style shooting matches

although changes to the cartridge body make for a better design overall, its in the small details
short/fat vs long/slender burn rates, shoulder/neck length and angle that help slow barrel erosion, etc
 
remington jim said:
6 CM cartridge design is superior to the old Whinny - Better coal and less brass stretch ! Comes with a 8 twist barrel .
Won’t out perform a 243 but I feel it’s a Better cartridge design .
Nothing wrong with a 243 Win . JMO RJ
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I had it explained why the 243 was known as a barrel burner, was to do with the shoulder/neck angle combo that directed hot gases directly to the chamber area just beyond the brass, the leade took the brunt of the heat
idk, not a rocket surgeon me
 
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