.243 Win to 6mm Rem bolf face

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I have a M700 short action in .243 Win. I am planning on varmint rig project on this action, chambered to 6 mm Rem.

There are very minor differences in .243 and 6mm case bases (within the bolt face) (.473 vs .472 rim width, 0.054 vs, .048 rim thickness, .470 vs .471 base thickness, respectively).

Is this anything to b concerned about, can I use the .243 win bolt face, without modification ?
 
243 and 6mm Rem fit the same bolt face...nominally .473"..but the cases can vary by up to .005 either way,mostly to the smaller diameter....maybe more. The rim thickness is a non-issue.
Go for it.
 
The short action 700 is too short for longer bullets seated out in a 6mm Remington, but in a varmint rig you usually single load anyway.
 
I'd go for the 243AI 't'were me.Good ballistics,long case life,same am't of work. The prob with 6mm Rem is the bullets must be seated deep in the short magazine.Mark
 
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GunTech/358:

I am going with a custom barrel, so the long length does'nt matter so much. I will have the barrel short throated so the bullets will approach the lands. I have not decided whether I will use the magazine for longer bullets; I may just load the 105-107 to a 2.95 COL and have the barrel short throated so the bullets will approach the lands (meaning I will single feed these rounds), and just accept more lead for lighter loads (75-87 gr) when seated to magazine length.

CamK:

The 6mm Remington has been my favorite long range varmint cartridge for years, and it is known to be exceptionally accurate. The 6mm also holds a little more powder than a .243, and with handloads will always be 50-150 fps faster (similar to .243 AI) than the standard .243. I also very much dislike the short neck on the .243 case, and much prefer the 6 mm case to handload with (can seat bullets out further).The long necked 6 mm will also have less throat erosion than the .243, which has a rather short barrel life, sometimes less than 1500 rounds. For long-range varminting, sending light bullets at ultra-high velocities, IMO the 6mm Rem has better case design than a .243 Win. And in a 10-twist, it is the best standard 1000-yd varmint caliber you can get your hands on period, IMHO.
 
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And the 6mm AI is even more of the same. I much prefer the 6mm over the 243, although power and speed isn't really the issue, as there is normally only about 100 fps difference between the two anyway. You'll see more of a difference between two rifles in the same caliber then that, quite often. - dan
 
Why go to the 6mm? It's a better cartridge.
Why not an AI? AI's suck! They gain you nothing except the opportunity to spend more on dies.
In a short action, the 6mm does require deeper seating of bullets. On the other hand, it at least has sufficient neck to allow you to do this without penalty. Regards, Bill.
 
Leeper said:
Why not an AI? AI's suck! They gain you nothing except the opportunity to spend more on dies.
Click to expand...

L.O.L. I love it Bill.:D I have built a lot of them and some are an improvement on the basic case but the cost of dies is way out of line... Pick a good cartridge to start with and you don't need to "improve" it.
 
Bill, Ackley dies are about $30 from lee. In a rem short action I doubt the 6mm case will hold much more powder than a 243 with the bullet 75% in the case. I have a 6mm. but it's on a long action. I would think the 243 ackley would have similar capacity to the 6 and work in a short action, even with long bullets. I'm using the wildcat 105's and for sure they wouldn't work in sa rem. magazine in a 57mm. case. To each their own, Mark
 
Lee doesn't list a lot of AI's.... and they are $36 US + etc.

VERY LIMITED PRODUCTION 2-DIE SETS $35.98
22/250 ACKLEY IMPROVED 90980 Serv.Parts
223 ACKLEY IMPROVED 90981 Serv.Parts
30/30 ACKLEY IMPROVED 90982 Serv.Parts
416 TAYLOR 90983 Serv.Parts
6mm/284 WINCHESTER 90984 Serv.Parts
6.5/300 WIN SHORT MAGNUM 90985 Serv.Parts
338/06 90987 Serv.Parts
257 ACKLEY IMPROVED 90988 Serv.Parts
280 ACKLEY IMPROVED 90989 Serv.Parts
30/284 90951 Serv.Parts
41 SWISS (load data not included) 90411
40/60 90214
45/60 90215
45/75 90216
 
they are/were $23 from midway and are exportable. Higginson has some as well. Also avail in redding bushing sets which are more $. FWIW I tried a 6mm in a 308 mag box and the bullet would be 75% in the case. As you know Rem are the shortest of the short actions. Mark
Edit, it was a 308 action I tried.
 
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why not go with a 6mm-.284 win. the case head is the same, short action is O.K., and it will kick the 6mm rem. big time.
 
"...so the long length doesn't matter..." It will for the mag. The max OAL for the 6mm is .115" longer. The case lengths are .188" different. It won't matter for a single shot rifle though. Although you may have ejection issues out of a short action. Single shot or not.
"...only about 100 fps difference between the two..." With like bullets. Not enough of a velocity difference to matter one way or the other.
The .243's major advantage is its widespread availability of ammo and brass.
 
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