Home Forums Hunting & Shooting Gunsmithing Rechamber Rem 700 from .243 to 6mm Rem?

Wondering what would be involved in rechambering a Rem 700 from .243 to 6mm Rem. Is that even possible? How much barrel length would you lose if it is possible?

Regardless of rechambering or rebarreling, will a Rem 700 short action work for the 6mm Remington with 95 to 105 gr match bullets (e.g., Berger VLD and Hornady A-Max)? What about magazine length - is it sufficient? Any other issues (e.g., feeding, etc.)?

A few weeks ago I looked on Remington's website to try to find some info about which length action they used for the 6mm Rem, but I came up empty.

I'll let the true gunsmiths answer the rechambering question.

As to action length, etc, a 6mm Rem works fine in a short action.

I had an early-ish Varmint Special in 6mm, it was built on a short action, and shot absolutely great.

Sold it ( ), missed it, and had another one built, again on a short action.

Recently bought a 40-X in 6mm Rem, on you guessed it, a short action.

I use mine for groundhogs and paper, so I never even bothered to check for mag length, etc, as they are always single fed. With you mentioning VLD's and A-Max's, I don't know what your intended use is, but that doesn't sound like something that you'll need a magazine full of ammo.

The 6mm Rem is an AWESOME cartridge, and I love mine. However.... if I had a rifle in 243 Win that shot well and still had good barrel life left in it, I'm not sure I'd go through the trouble and expense of rechambering it, "just because".

If on the other hand it's shot out, go ahead and re*barrel* with a fresh tube in 6mm Rem.

You won't regret it!

I'm afraid it's NOT possible. If one would take a good look at a reloading manual, one would see that the .243 is shorter but fatter. The 6mm is longer, but skinnier with more case taper...

In actual usage, there is not enough difference to make a signififcant gain in velocity. If one has a "fast" .243, it can and does often shoot higher velocities than a "slow" 6mm. What I'm saying is that the difference is less that the difference between a "fast" and a "slow" bbl.

A .243 will kill a deer just as far away as a 6mm given identical bullet placement... And just as dead! And if you don't believe me, perhaps you should get one of each, and start chronographing... It'll open your eyes...

GH

Thanks. I was wondering if the difference in the shape was enough to make it infeasible - that's the main reason I asked.

You might want to look into rechambering to 6mm Ackley Improved. I think the AI version might be blown out enough to clean up the 243 chamber. Can't find dimensions right now for the 6mm AI.
Royce

If you really want a 6mm Rem, just rebarrel. The 6mm will not disappoint you. You could probably get $75 (+/-) for your old barrel and that would offset your cost a bit.

Had a custom rifle/barrel, 243 rechambered to 6mmAI and the barrel had to be set back to clean out the 243 chamber.

What do most smiths y'all use charge to set back a bbl and rechamber?
I'm thinking the same or maybe just going 243 AI.
Also if throat looks crappy will setting back and rechambering help that issue any? I'm pretty sure I'm dealing with a 10 twist bbl and it's on a SA model 70 push feed. Have no idea of condition of bore or throat. It's a 30 year old win 243 varmint rifle w a heavy factory tube.
Thanks