.243 Win or 6MM Rem?

[Jailer]

Thinking about building another varmint rig and wanted to know what would be a better choice, the .243 Winchester or the 6mm Remington? Pro's and cons? I'm inclined to use a short action Remington 700 action (for the .243 Win), or I could use a custom Mauser 98 (long action). Not long ago I used the gunsmithing services of Mike Bryant, Wheeler, TX., to build a 22BR varminter and it turned out extremely well. Not sure who I will use this time. Thanks!

 

[suzukisam]

Well I don't use 243 for varmints. But I use it for everything else. I hand load and I love the availability of brass.. I've picked up literally a thousand tbs at the local gun range over just a few deer seasons. My vote would be 243 just for the availability

 

[TexasPatriot.308]

they are so much alike it is just a matter of what you choose, don't see one being much more than the other, but to be different I would go with the 6mm

 

[matrem]

There's actually a noticeable difference between the two.

.243 has far more support as far as rifles and brass go.
6mm has a hundred or more extra fps in it.

 

[1948CJ2A]

There's actually a noticeable difference between the two.

.243 has far more support as far as rifles and brass go.
6mm has a hundred or more extra fps in it.

Yep.

The 243 Win is a 308 necked down to 6mm whereas the 6mm Rem and original 244 Rem is a 7x57 necked down to 6mm. Because of this the 6mm Rem has more case capacity than the 243 Win.

When Remington came out with the 6mm Rem it was called the 244 Rem and it only came with a 1-12" twist meaning it couldn't stabilize the heavier bullets for deer-sized game. In the same year, Winchester introduced the 243 with a 1-10" twist. This catapulted the 243's popularity over the 244 Rem. By the time Remington corrected the problem in 1963, it was too late.

Still, from a ballistics standpoint, the 6mm Rem is superior in terms of velocity especially for handloaders. The argument is similar to that of the 7-08 versus the 7x57 with the main difference being no need for considering old weak military actions when working up loads.

I prefer the 6mm Rem if picking between the 2; however, if you're not handloading, factory ammo is much more readily available for the 243 Winchester.

For what its worth, in thumbing through my Hornady 9th Edition book, the 2 are identical in terms of velocity through most if not all of the loads documented. (Keep in mind, Hornady's book rounds off to the nearest 100 fps, which is irritating to me). The Nosler 6th Edition book shows their 55gr BT to yield 4032 fps in the 243 Win's fastest load and 4086 fps in the 6mm Rem's fastest load. On the other end of the spectrum, the 95 gr BT yields 3144 fps for the 243 Win's fastest load and 3261 fps for the 6mm Rem's fastest load.

Some might call this splitting hairs or "marginal" differences. Personally, I think it makes things more interesting, especially in an era when all you see is the same 4-5 cartridges (243 being one of them) with plastic stocks and matte-finished metal.

 

[Fred Fuller]

.243 Win or 6MM Rem?

Sounds like a gun magazine cover article from the mid-1970s

For a pure varmint rig, 6mm...

And even with the discussion raging as it was in 1974, I bought a 6mm ... a Ruger Model 77, from the J&G Rifle Ranch. Topped it with a Weaver V-7 and have not looked back, save to replace the glass when the Weaver finally died. I still have some .244 Rem brass, too

Used it on deer and varmints, handloads across the board.

But when my wife wanted a deer rifle a few years back, I got her a .243.

 

[MachIVshooter]

If you handload, the 6mm is a superior choice. Not just the 100-200 FPS advantage (yes, 200 with the lightweight bullets.......and it matters with varminting), but also the very long neck gives you a lot more flexibility with bullet seating depth.

If you're buying factory ammo? Also a no-brainer. .243 is everywhere, there are about 4 factory loads for 6mm rem, none of which are spectacular or easy to find locally.

 

[rcmodel]

The 6mm is superior from a hand-loading standpoint in that it has a longer neck, and slightly more powder capacity & velocity.

On the other hand?

It is an almost obsolete caliber today, and factory ammo & brass is very hard to find.

With factory loads, the .243 will do anything the 6mm Rem will do.
And you used to be able to buy ammo for the .243 at Walmart & the farm supply store.

rc

 

[243winxb]

243 win.

 

[Palehorseman]

Did they ever decide what twist for the 6mm? At first 1:12, then 1:9, then renamed it .244 Remington and confusion reigned, Winchester came out with 1:10 for .243 and never looked back.

 

[MachIVshooter]

Did they ever decide what twist for the 6mm? At first 1:12, then 1:9, then renamed it .244 Remington and confusion reigned, Winchester came out with 1:10 for .243 and never looked back.

Other way around. It was introduced in '55 as the .244 with 1:12, renamed to 6mm concurrently with the change to 1:9 rifling.

Custom barrels have been made in twists all up and down the chart, but industry standard is, and has been for over 50 years, 1:9.

 

[bannockburn]

I would go with the much more mainstream .243, typically available anywhere ammunition is sold.

 

[Jim Watson]

A friend has a full house 6mm Rem target rifle. I can't see where the sharp pencil design 6 - 6.5 mm rounds have any advantage.

Winchester beat Remington on marketing but not on ballistics.

Either is nearly as good as a properly chambered and loaded .257 Roberts.

 

[dvdcrr]

If you go with 6mm get a high quality match barrel and find a load thatallows .030-050" jump with good accuracy. That way you dont have to worry about mag length issues. Its a great round but a short mag. Will not always allow you to seat to the lands. And 1:10 twist is fine for most bullets but long bullets will require tighter twist.

 

[KenW.]

Millimeters? Sounds like what them nazis was shootin. Stick with American units of measure!

 

[Bushpilot]

If you're not a hand loader then it's a no brainer, 243 all the way. If you want a wider selection of available rifles, less hassle finding components and less overall expense then it's still .243 whether you hand load or not.

Now on the other hand, if you're a hand loader that actually wants to squeeze every drop of performance out of his rig, which sounds at first like something that every one would automatically want to do but in reality doesn't. There are a lot of hand loaders out there who reload because they want to save money, shoot more, simply enjoy it or whatever and who in practice just duplicate the factory or even water down their loads. However, if you're like Jim Carmichael and "buy a race horse because you want it to run" then maybe you should opt for the "Betamax" of 6mms, the 6mm Remington. Just keep in mind that this may be one of those times when the highest performance potential may not be the best choice and in the long run you might be happier with VHS… errr… I mean a 243.

 

[ApacheCoTodd]

.243 - that's for me. That makes 6 is a nix.

Versatility, re-sale, 6 is 1/3 evil, one-off reloaders are weirdos... Don't be that guy!

 

[HOOfan_1]

If I were building from the ground up, I would go with a 6mm...but I am a reloader, and you can form 6mm brass from the various x57 Mauser cartridges, so availability of brass really isn't a problem.

Since it is a custom gun, resale value seems like a Red Herring too.
You can also get a custom gun with any twist rate you want...so the 6mm is just as versatile as the .243.

 

[frankenstein406]

6mm if you reload, or have them available locally.

 

[CB900F]

Jailer;

If you handload, it's the 6mm every time. I have never had a problem getting brass either. I believe the idea that you can't is just bunk. For a handloader, the major advantages have already been stated: more case capacity and a longer neck.

I use mine as my primary coyote gun, with the 75 gr Hornady V-Max bullet doing the work downrange. I live in Outer Montana on the front range. In other words, the wind blows, sometimes with hurricane force. Not that I attempt to shoot in high winds, but the 6mm allows me to keep velocity up and use a heavier bullet that is better in the wind. 'Cause ya know, those pesky coyotes just won't let you shoot with the wind at your back. Something about 'em scenting you and then departing the location at fairly high speed.

I've also used the cartridge as a deer gun. There I went to the excellent Speer 90 grain spritzer. That bullet was created for the 244 when it couldn't stabilize a heavier one. Therefore, it's built stout enough to very effectively do the job on either mulies or whitetail, and I've taken both with that round. The 90 grains allow some extra velocity, which the 6mm can deliver without raising a sweat or a primer for that matter, and the bullet's darn near got a halo on it IMHO.

The 6mm's everything the .243 wants to be when it grows up.

900F

 

[Sunray]

The only real actually noticeable difference is about 100 FPS with like bullets, .188" in case length and the .243 being readily available everywhere. Toss a coin.
"...American units of measure..." Your money is Base 10. Just like metric. snicker.
"... gun magazine cover article from the mid-1970s..." 50's, 60's, 80's and 90's too.

 

[suzukisam]

You can get most any brass if you look hard enough.. not saying 6mm is hard.. I just like that I can go get bucket fulls of top quality once fired from the range. At deer season pick your favorite brand and wait for the guy shooting it to give it to you or throw it in the bucket. For me brass is free for the 243. I don't load long OAL cause I'm feeding it through an AR anyway. I don't think anyone is saying brass is impossible. Just that 243 is about as easy to get as candy in Charlie's factory! Next to -06, 308 and 270 it's at the top for deer cartridges around here. (Kansas city metro) I only shoot my loads. And when you take the cost of brass out, Loading is economical again, with the price of powders anymore..

 

[Bushpilot]

edit

 

[moxie]

If you're old enough to remember Robert Ruark, his favorite rifle was the .244. He claimed to have shot just about every game animal in Africa with it except the elephant and cape buffalo.

Re-named the 6mm, it gets a few hundred fps more than the .243. Since I know the .243 will cleanly take black bear, deer, and big bull elk, the 6mm can certainly do as well or better.

I agree with many of the posters who opt for the .243 if using factory ammo, but 6mm if a reloader. Both fine calibers.

But, if I were building a pure varmint rig, I would drop down to .222, .224, or .22-250. Use lighter bullets, possibly less recoil, with considerably less powder.

 

[dvdcrr]

The 6mm's everything the .243 wants to be when it grows up.

Heck I'm not everything I want to be when I grow up!
Don't forget about 6mm/284 Win