HuntingNet.com Forums - .243 vs. 6mm

HuntingNet.com Forums (https://www.huntingnet.com/forum/)

- Guns (https://www.huntingnet.com/forum/guns-10/)

- - .243 vs. 6mm (https://www.huntingnet.com/forum/guns/183315-243-vs-6mm.html)

RE: .243 vs. 6mm

Quote:

ORIGINAL: Rammer

243 if you buy factory fodder. 6mm if you handload.

Yep. I prefer the 6mm personally. Little bit faster, much more reloading friendly case.

Barrel twist will not be a problem if you have to rebarrel... because you can pretty much pick out the twist you want. Go with a faster twist for your heavier 95-100gr deer/antelope bullets, or a slower one for 55gr varmint bullets.

RE: .243 vs. 6mm

If you want the 6mm, get it, there's no way you're going to regret it, but if you get the 243, you might regret it.

P.S. I don't have a .243, never have, I'm a .308 guy.

RE: .243 vs. 6mm

Unless you handload or have a good supply of ammunition I would just get a .243. No deer wil ever know the difference.

RE: .243 vs. 6mm

Quote:

ORIGINAL: younggun243

if you get the 243, you might regret it.

Can you explain?

RE: .243 vs. 6mm

Quote:

ORIGINAL: Yoter

I killed my first two deer and first two antelope with a Remington 6mm, not to mention it was the gun I really learned to shoot with after graduating from the .22. My dad still has the 6mm and is saving it for the grandkids (my kids) so I won't be getting my hands on it any time soon.

My next gun will either be a 243 or 6mm. I can see the advantages of the 6 mm over the .243 although slight. My heart wants the 6mm for sentimental reasons, but my head is having a hard time justifying not getting the .243.

My questions is, how difficult would it be to get a 243 and then have a gunsmith rechamber it for the 6mm? Would the rate of twist in the barrel be an issue? Will the magazine have to be replaced? How much would it cost?

The only factory new rifle I am aware of still made in 6mm is the Remington VLS, and I'm not sure I want this to be a heavy varmint rifle. I plan to use it for coyotes, antelope, and wolves.

It could be done, but the .243 barrel would probably have to be set back several threads, and shortened. The reason is that though shorter, the .243 case is larger in diameter at the shoulder than the 6mm Rem. case, so if you merely ran a 6mm reamer into the .243 chamber, you'd get an enlarged "hump" in the 6mm casejust behind the shoulder when you fired the gun, at the spot where the .243 shoulder is.

However, a 6mm Remington IMPROVED reamer (such as the Ackley, at .457" at the shoulder,or the Page Super-Pooper) might have a big enough shoulder diameter to clean up the .243 chamber without having to set the barrel back. I don't really know....

RE: .243 vs. 6mm

If you handload, buy the .243 and have it reamed to .243 AI. The performance will be enhanced enough to get you the 6mm zip you want and still be recoil friendly to anyone. You can shoot factory .243 out of the improved if you ran out of ammo in a pinch.
Accuracy with a 40 degree shoulder seems to be a bit better than the standard 17-28 degree cartridges. I'm not exactlysure why, but it is. It may be headspace and datum line stuff, but someone on this forum could answer better than I.
Just some comparison data:
75 grain bullet .243 Win .243 Win AI
46 gr of IMR 4350 =3415fps50grains 4350=3765fps
A little more powder capacity and 350fps faster.All my improved riflesshoot MOA or better.The best of both worlds can be achieved with improving a cartridge. A safe increase in powder capacity( 5 to 10% more)yields more speedthus flatter shootingfor a bit more distance if needed, more energy and accuracy that exceeds the normal factory production ammo.
A competent gunsmith with experience inthis aspect of re-reaming to improved canmake your rifle be more than you expected.
Good luck!

RE: .243 vs. 6mm

Thanks for all of the replies. I do handload, so ammo availability would not be too much of an issue. I am going to do some more research on the 243 AI. Anybody know of some good sources of info?

RE: .243 vs. 6mm

Quote:

ORIGINAL: ipscshooter

Can you explain?

Because for him, like he said, ammo availability isn't a problem, and he's sentimentally attached to the 6mm Remington.
If ammo availability is no object, then he should get the 6mm, it's ballistically superior, and most importantly,it's a cartridge he's familiar, and comfortable with, and THA, is the most important thing.

RE: .243 vs. 6mm

You could easily rechamber to .243 AI, but the barrel would need to be set back enough so that the bolt won't close on the Go headspace gauge.

One other comment: although I know there a many shooters who have gotten good accuracy out of the 6MM Remington, I feel like the average .243 Win will group better than the average 6MM Rem. Same deal with the 30/06 and .308 Winchester. Or the .300 Winchester compared to the .300 Weatherby. Individual rifles vary, but if you took an average . . . . . .243 Winchester comes out ahead.

RE: .243 vs. 6mm

Yoter-

I just sent a new Remington 700 VS .22-250 out to Kevin Weaver at Weaver Rifles in Colorado. He's going to ream it out to 22-250 AI. He's one of the best wildcatters and his prices are very reasonable. You can look up his web at weaverrifles.com or call him at 719-683-3024. He is a very kind gent who can and will explain all your options when deliberating an upgrade to making a cartridge "improved".
It can't hurt to call and if you read his web, you'll start to see why improved rifles are a step many shooters take when seeking the ultimate from a cartridge.
Best of luck!