Chambering a handi platform into 6mm rem

[sunsetrider2012]

Just curious if you guys have seen this done or have had it done.  Maybe you have someplace you would get this work done at,, I have tried a few smiths up here but didnt want to tackle the problem.    I have a 22-250 bull barrel that i would sacrifice, for the project.  or maybe you  know of some barrels available for the project with a 1:10 twist or faster.  I look forward to your  responses

[quickdtoo]

A 22-250 will require reboring since is has a .224" bore, the 6mm requires a .243" bore, a suitable donor would be a 243 Win barrel if you do a 6mm Rem Ackley, the 6mm Rem won't clean up a 243 chamber, but the Ackley will,  I have done exactly that with a 243 t-hole Ultra Varmint, it has a 1:10" twist, Wayne York did the work.

Tim

http://www.oregunsmithingllc.com/

[sunsetrider2012]

A 22-250 will require reboring since is has a .224" bore, the 6mm requires a .243" bore, a suitable donor would be a 243 Win barrel if you do a 6mm Rem Ackley, the 6mm Rem won't clean up a 243 chamber, but the Ackley will,  I have done exactly that with a 243 t-hole Ultra Varmint, it has a 1:10" twist, Wayne York did the work.

Tim

http://www.oregunsmithingllc.com/

I completely understand that for sure,   thats why i chose the bull barrel to rebarrel to 6mm, to cut the new diametre and rifling in how i want it,, and thanks for the link,, I have thought about a 6mm AI but havent took that plunge yet

[cudatruck]

i want to do a .243 R.K.B. it is a 30-40 krag necked down to 6mm. but to do in a handi will require a stub job. The cost is keeping me back. I looked at the 6mm rem AI but it's rimless and i have a really old die set marked .244 krag that i would like to get to use. would it not be cool if we could buy un chambered barrels from the factory? i found instructions on fire forming cases in the form die, but have not had the guts to try that yet....

[jeepmann1948]

The 6mm Ack Improved is a simple re-chamber for the 243 Win Handi. Just ask the gunsmith to make sure the barrel is centered from the center of the bore. Not all handi Rifles are . Don't worry after it is centered properly and re-chambered it will be fine.It also fixes the off center firing pin strikes too.
  The 6mm AI is a great cartridge. I do not hot rod mine  in the Handi I just load it to where it shoots well and quit. Brass lasts a long time.Dies are not as cheap as regular 6mm but a Lee Collet sizing die works well for  the sizing procedure.I found a full length set of RCBS dies on Ebay for 35.00 so they are out there.
 I would think you could trade your 22-250 barrel for a 243 barrel here on GBO and come out  a lot cheaper than a re-bore.The factory 243 has a 1-10 twist which should work fine for anything but the super long heavy bullets (115 and up)
Just and idea
Good Luck
George

[kennyd]

Is there that much improvement over the .243 Win to have to go to all the bother and cost?  The .243 is a fun little gun, and ammo is more available

[sunsetrider2012]

Is there that much improvement over the .243 Win to have to go to all the bother and cost?  The .243 is a fun little gun, and ammo is more available

Take your 243 and a 6mm side by side on the bench, and you will notice the difference , not a lot but noticable, in energy down range, the 6mm is a 243 on steroids, the 243AI would be comparable to the 6mm,   I compete with both of them, My preference is the 6mm hence why i would spend the extra to get a barrel cut, now the other option is a 6mmAI  i just havent taken the plunge yet.   I do run 1 wildcat in  6mm on a savage platform,, in a 6mm/30-30 AI  was 1 of the last barrels produced in PO Ackleys shop for the savage 99,,  it is basicly a 22 hi-power necked up to 6mm/243 with a 1-9 twist.  I Just fell in love witht he 6mm rem cartridge many years ago. and 1 on a H & R platform would be the cats meow, if it shoots as good as all the other H&R's I own.

[gcrank1]

Hey SSR, why not do a 243AI first at reasonable expense and work it out for us  . Im sure you wouldnt have any trouble moving it here if/when you want to move on to another project (or just maybe it would be the cat's meow and a keeper?).

[quickdtoo]

Why the 6mm Ackley over the 243 Ackley? In a Handi you can't make a true 243 Ackley from a 243 Win, you end up with something a bit more and have to fireform factory brass with special steps due to not being able to set the barrel back, the 6mmAI will clean up the 243 chamber and allow 6mm Rem brass to be fireformed easily. There are other advantages as well. 

Tim

http://www.6mmbr.com/gunweek042.html

Choice of Caliber--Why the 6mm Rem AI and not a .243 Ackley
When asked why he prefers a 6mm Rem AI over the more common .243 AI, Richard replied: "I've probably built over one hundred 6mm AIs in the last three years. It's been my favorite long-range varmint cartridge for years and years. Over the years I've put together heavier-caliber rifles hoping they would be a better windy-day long-range varminter than the 6mm AI. I have always gone back to the 6mm AI because it is so hard to beat. High velocity with explosive bullets is a varmint hunter's delight (unless he is skinning out the critters). The other school of thought is to use VLD bullets at a much lower velocity (VLDs do no not like to be shot so fast). It is true that the VLDs will reach out at much longer ranges and buck the wind better, but they sometimes pass right through a critter leaving only a pencil-hole. The wounded varmint will then drag away to his den. Prairie dogs are easily killed with the VLDs due to P-dogs' small body mass, but on larger varmints, such as groundhogs and coyotes, you will get a lot of cripples. My favorite 6mm AI is set up with a 14-twist HV barrel shooting the 75gr V-max at 3800+ fps. My second favorite setup is with a 10-twist HV barrel shooting the 87gr V-Maxes. The reason the 75-grainer is my favorite is that 80% of our hogging is at ranges of 800 yards and less and the 75-grainer works its magic at these distances.

Comparing the 6mm Rem AI with the .243 chamberings, I think the 6mm Rem AI comes out on top. The 6mm AI is ALL the cartridge any varmint hunter needs. It will do anything you want to do with varmints, any kind of varmint. And in a 10-twist, it is the best 1000-yd varmint caliber you can get your hands on period. The long-necked 6mm AI will have less throat erosion than the short-necked .243 or .243 AI. The 6mm Rem AI will also hold a little more powder than a .243 Ackley. For long-range varminting, sending light bullets at ultra-high velocities, I just think the 6mm Rem has better case design than a .243 Win. With either case, definitely go with the Ackley version. The 40° shoulder gives you a little more powder capacity and both the shoulder angle and the reduced body taper give you better brass life. A case with no taper won't stretch as much as a tapered case."

[gcrank1]

Sure sounds like that is the way to go..........I respectfully withdraw my above suggestion!

[jeepmann1948]

Another reason I like the 6mm Ack Imp is that I own a chamber reamer for it!
happy Trails
George

[sunsetrider2012]

Now Thats some information I like to see.    I might just have to take the plunge on the 6mm AI now. And I do have a fellow with  reamer not far from here.