.243 Winchester to 6mm Remington

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UncleDoc

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I have been studying the SAAMI drawings for these two cartridges and I have concluded that the .243 cannot be rechambered to the 6mm without cutting off the back of the barrel and advancing the chamber a couple of threads, which most gunsmiths do not want to do. Am I correct or does anyone else have experience with this conversion?
 
For what rifle? Is a factory or aftermarket barrel replacement an option? If so this is sometimes a cheaper option unless you have a gunsmith who will work for very low rates.

Grouse
 
The rifle is a Remington 700 and smith1559 is correct that an AI would be a better conversion. I think it takes considerable length to cleanup a .243 Winchester chamber for anything else.

I may have some pictures of my favorite gunsmith with a goat that I don't think his wife has seen yet. I'll talk to him about the conversion and the photos.
 
Why go to a 6mm over a 243?? I have had both, and like the .243 better.. My shooting pal was a die hard 6mm fan, until he got a .243.. Now the 6mm's have gone down the road, and he uses the .243.. On a short action, the seating depth is pretty restricted with a 6mm, but about perfect for a .243.. A 6mm on a longer action, now I think that would make a difference.
 

You cannot re-chamber a 243 to 6mm with a one turn setback - the body is fatter on the 243. You have to remove the entire 243 chamber.

But you CAN do a 6mm Ackley Improved without setting the barrel back at all - it will clean out all of the 243 chamber in one pass. It is a very good round

 
Originally Posted By: CatShooter
But you CAN do a 6mm Ackley Improved without setting the barrel back at all - it will clean out all of the 243 chamber in one pass. It is a very good round



I'm very interested in this for a project. Do you have one?

And if so, details, pics,etc.?
 
Originally Posted By: LungbusterOriginally Posted By: CatShooter
But you CAN do a 6mm Ackley Improved without setting the barrel back at all - it will clean out all of the 243 chamber in one pass. It is a very good round



I'm very interested in this for a project. Do you have one?

And if so, details, pics,etc.?

I had one, but don't any more. It is a common wildcat and any decent 'smith can do it for you.

Dies are readily available.
 
Originally Posted By: UncleDocThe rifle is a Remington 700 and smith1559 is correct that an AI would be a better conversion. I think it takes considerable length to cleanup a .243 Winchester chamber for anything else.

I may have some pictures of my favorite gunsmith with a goat that I don't think his wife has seen yet. I'll talk to him about the conversion and the photos.

If I understand your post correctly your wanting to rechamber your factory barrel?IMHO I wouldnt spend that kind of money on a factory tube.I would save a little more money and get a new tube.
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After considering the options I think the new tube is the better of all options. Yes, it is an older factory Remington barrel. Problem is it shoots really good as a standard .243 Winchester. I know there are other 6mm calibers that are a little more efficient, have less negative effects on the throat and barrel, and do not count on factory ammo, which I am fine with. I will likely continue to shoot the .243 Winchester and then retube to something else when it quits shooting good. Thanks for all the input. All good stuff...
 
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Originally Posted By: UncleDocAfter considering the options I think the new tube is the better of all options. Yes, it is an older factory Remington barrel. Problem is it shoots really good as a standard .243 Winchester. I know there are other 6mm calibers that are a little more efficient, have less negative effects on the throat and barrel, and do not count on factory ammo, which I am fine with. I will likely continue to shoot the .243 Winchester and then retube to something else when it quits shooting good. Thanks for all the input. All good stuff...

Nothing wrong with rechambering a factory tube, even one that's used if it's a good one. Depends on what you're after. As an AI your good shooting .243 will shoot the same only faster. My first 243AI was on a Rem varmint BDL I'd bought used. The bore was excellent and it shot very well. The .243 load was a 60@3800. Rechambered to 243AI it shot 70's at over 3800. If that sounds like what you want, then do it.
 
You can still shoot factory .243 in it as well, can't you? Though, I believe it's not as accurate. It would do in a pinch. I helped a guy blow out some 7mm-08 to AI one day. It was fun to burn some ammo with that little 700
 
Originally Posted By: trimble s6You'd be surprised at how accurate standard cartridges can be in an Ackley chamber...............

+1
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