.243win to 6mm Remington

[Millsy525]

I am really keen to own a 6mm rem.

I dont know why there are no factory rifles made in 6mm anymore.
The reasons are plenty of projectiles to choose from, performance edge over the .243win, longer case neck reducing throat erosion compared to .243

I plan to pick up a well used .243(or .308), rebarrel to 6mm, replace with tactical stock and trigger work/replacement
What is a good action to start with?
The gun will be my long range varmint rig (I have .204 for ranges to 400 yards)
Magazine capacity of 5 rds or more, solid scope mounting (integral rail maybe), good bedding surface and recoil lug are essential elements of the action I start with

Any help much appreciated

[JASmith]

Have you looked at the .257 Roberts?  It is also a necked down version of the 7X57 Mauser and is a very fine deer cartridge with bullets up to 120 gr.  It also has significant varmint capability with bullets down to 75 gr.

[pastorp]

not convinced the 6mm is that much better than the 243. However if you want to build a riffle and use a 243 or 308 action then I would build a 25/08. No feed problems and something a little different.

Regards,

[Brithunter]

Hmmmm in theory it looks like the 6mm Rem should have the advantage over the 243 Win but it does not seem to come about in real terms. I was not aware that no new rifles were being chambered in 6mm Rem anymore   but I do know that 243 Win is far easier to get ammo and cases for.

Here in the UK, and especially where I live, anything apart from Primers and bullets, so that's cases and factory ammunition has to be special ordered for the 6mm Remington whilst you can have our choice for the 243 Win.

If you decide to go the 6mm Remington route then may I suggest you stock up on cases   that is unless it's popular in your area. Earlier this year I brought my second hundred 6mm Rem cases and next year will get another 100 cases for it.

[pastorp]

Brithunter, Why only 100 cases at a time? Are you limited by law or price? Just curious.

I try to buy by the thousand when I buy cases.

Regards,

[Savage .250]

  To me that`s like trying to build a better mouse trap.  I`ll leave it at that.  

[Brithunter]

Brithunter, Why only 100 cases at a time? Are you limited by law or price? Just curious.

I try to buy by the thousand when I buy cases.

Regards,

Cost  and lack of funds. Too many projects going on as well. Cartridge cases are not licenceable unless their primed then it's grey area.

[Mikey]

I think the main reason you do not see new rifles in the 6mm or 244 is because the 243 may be the better cartridge.  I believe the 243 has a wider application and the twist is more conductive to a larger selection of bullets. 

I see the 243 has a 1:10 twist, the 6mm a 1:9 twist and the 244 a 1:12 twist.  The 1:10 seems to stabalize a wider variety of those 6mm pills than the other two twists. 

I also do not see much if any difference in the case dimentions so I think it is a matter of the bullet weight and the twist as to accuarcy.  The 6mm/244 was introduced in 1955 and re-introduced in 1964 with a 1:9 twist to stabalize heavier 100 gn 6mm bullets. 

Even though the shoulder angles are a bit different I suppose that if you really wanted to you could probably get a custom 6mm/244 barrel with the 1:10 243 twist and nobody would ever know the difference...

[billy_56081]

If you are talking rechamber this won't work if you look at the cartridge drawing you will see there is less taper in the 6mm rem case. Now you could rechamber to a 6mm AI.

[Brithunter]

Hmmmm Mikey .................. my 6mm rem chambered rifle has a 1-10 twist rate and yep it's the factory barrel  the rifle is a Parker-Hale 1200V.

[Silvertp]

Millsy...

Ive heard the .243 vs 6mm debate ad nauseaum.  Sometimes a guy just wants something, so if its a 6mm go for it!  Personally, Ive owned 3-6mm's and 0-243's.

The twist debate is dependent on the wt. bullet you want to shoot, as Im sure you know.  Figure out what bullets you want to shoot, then buy your bbl /twist accordingly.  I had a hvy bbl 6 from Ruger and it wouldn't shoot heavy bullets but my oh my would it shoot a sweet little group with 85 gr. Speers.  Bullet wt. in turn is most likely dictated by the type of vermin you want to harvest, and if youre looking to fill the 400+ yard void you probably will want to shoot 90 - 100 grain bullets.

I don't think you could go wrong with a Remington 700 action or a Sako action.  The 700 action would be a lot cheaper and easier to come up with as a "used" firearm.  My current 6 is built on the Sako II which is a nice length for the 6, with a Shilen bbl.  I built it thin and light for use as a mtn rifle, but it still shoots 1/2 groups at 100yds with nosler and hornady 100 grainers.   Probably wouldn't hold up to well on a prairie dog town, but its a great gun for long range coyote thumping.

Let us know what you decide to go with.

Silvertp

[yooper77]

6mm Remington performance over 243 Winchester = Zero.
243 Winchester ammo is easier to locate plus if you reload the brass is also easier and cheaper to buy.

Velocity isn’t a performance measurement, delivering an accurate bullet on target should be your goal.

If you want a 6mm Remington no problem there are many good platforms to choose.

I would strongly suggest a 6mm Ackley Improved over the standard 6mm Remington; you will have long case life with less trimming.

yooper77

[no guns here]

I too have a 6mm Remmy from Ruger.  It's a Model 77 with a heavy barrel and yes, it does SHOOT those 85 grain bullets quite well.  Cover them with a dime if I do my part...

Just destroys 'yotes...

Takes deer with a good shot...

Makes crows EXPLODE.

Pumpkins turn into pie filling...


That's all I've ever shot with it.


NGH

[leather5to1]

Never had an luck with a 243.  I have and love my 6mms though.  From my experience the 6mm has more inherent accuracy.  I have a remington 700 adl sporter.  It is a consistent sub half moa gun with 85 grain gamekings.  I have seen the same load do excellent in our family's 2 40xs and all other sporters.  I would think the best way to get a good shooter and do it all yourself is to find a cheap savage 10 or 12 with a standard bolt face and rebarrel.  You would then have a good gun with a match barrel in an excellent chambering.

[Brithunter]

Hmmm well I was never really intersted in the 6mm/243 as all that I heard led me to believe that they were fairly fussy about likes and dislikes in bullets and ammunition. Add to that the fact that the Police here like to foist the .243 mainly on folks as it's the minimum, or was, legal for deer.

However I stumbled upon a rather nice looking Parker-Hale 1200V in 6mm Rem at a very good price  so I got a 6mm and the journey started. A while later whilst looking for a BSA for a friend in NZ I stumbled across a BSA majestic in yep .243 that has the BESA Recoil reducer machined into the barrel and it had the Range Adaptor fitted that closes off the muzzle break so I acquired a .243 as well  I am sorry to say that some misguided sole (former owner) had wrecked the barrel channel bedding and the action bedding (obviously someone who had swallowed the free floatign mantra) so I had to play about with wood filler and see if it could be brought back and I succeeded  and test shooting it the rifle shows promise so now once I get the finaces straight, next year now at least  , it will go off to Les and have the bedding repaired properly and tested with factory ammo and come back shootign as well as it can  .

Meanwhile I came across a Parker-Hale 1000 with 8x56 scope again in .243 that has the barrel screw cut for a sound moderator and I had be deliberating which rifle to have screw cut, now I don't have to decide and I have not got a model 1000 as yet  . Then to cap it all a friend has had to give up his FAC and has offered his customised Midland 2100 again in .243 so suddenly I will have 3x .243's and a 6mm  and thats' why the finances will take a while to recover 

[gypsyman]

I've got a 24'' barrel for my Encore in 6mm A.I.--1-9 twist. Fire forming brass with 105gr. Best group so far is a little under an inch at 100yds, which am sure will improve when I get some time to work up a better load. Havn't had time to chrony the loads yet, but accfording to the books, will get 400fps better than a .243 with 90grs. So far I'm happy with it.  gypsyman

[Emmett]

If you decide to go 6mm, I would advise that you consider building on a long action. A lot of .243's can use up the magazine length by seating bullets close the lands in a short action, let alone a 6mm.
  Ackley Improved (AI) would be another option you may want to consider. You can have either a 243 or a 6mm chambered with the 40 Deg. AI shoulder when you order the barrel. The twist rate is up to you, and will be picked at this time. The gunsmith should finish the chamber a little short so fireforming the AI casings from factory brass will be a piece of cake.
   As far as donor actions, I recommend the Rem. 700 in BDL, or any model that gives you the bottom metal with the donor gun. This includes the floorplate/trigger guard assy., magazine box, spring and follower, etc. You will pay a lot extra to get those pieces if you use an ADL action and want the floorplate convenience. It's just better sense to buy it all in one gun.
    The factory stock from the donor gun could POSSIBLY be used, but you probably will want to opt for an aftermarket of some sort. Remember that the new barrel will most likely not have the same contour as the factory barrel, unless you ordered it that way or your gunsmith will reproduce the factory contour for you. The stock dimensions are going to be different, most likely.
     Just some things to think about, but definitely a fun thing to do.

[Swampman]

Hummmm....I've never seen a .243 Winchester that shoot over 3/4 MOA.  Most are much better than that.  The 6mm Remington is an ok cartridge.

[Brithunter]

Oh dear swampy  you have led a sheltered life  one reason I kept clear of the 243 Winchester is that it's, or can be, very fussy about bullets it's fed. Here most folks use the 100 grain bullets for deer to stay within the legal limits imposed on power and bullet weight depending on where your hunting. A lot of .243's will not group the 100 grain bullets well. In fact a friend had a particular rifle that he brought for his intended  that would not shoot any bullets over 95 grains in weight with any accuracy. 100 grain factory federal which is known to be accurate did patterns of around 5" at 100 yards. Yet feed it 85 grain bullets and it tore out little bug holes.

I ended up with a .243 Win that is fussy but it does have bedding problems due to a moron who owned it before and swallowed the free float mantra rubbish and wrecked the bedding and barrel inletting. I need to get it rebuilt by a competant stock maker  . It was not the chambering and calibre I wanted but the rifle as it had features I did not have in my collection but heck we have to try them out don't we. 

Now it seems that they are multiplying on me as before long I will have three rifles chambered for the .243 Winchester cartridge  out numbering the poor lonely single 6mm Remington in the rack here.

[Swampman]

Let me guess.....they don't sell Remington ammo over there.

[Brithunter]

Yeah they do but they sure is proud of it I tried getting some 100 PSP Remington in 6mm Rem and was quoted £132 ($205:92USD) per hundred and a wait of up to 6 months  they did have some in .243 Win which is 80 grain PSP (R243W1) I have what's left (12) here of a box I brought to try. I shot the 8 in testing and it grouped so poorly it was a waste of time and ammo so I stopped.

I went back to the shop and picked up a box of 100 grain (243B) Federal Power-Shok (gee you'd think with their higher education they would learn to spell  ::)Sheesh) it shot better and I have started handloading those cases, the handloads are showign promise but are not giving the accuracy I woudl expect as yet!. The Federal was actaully the same price as the 80 grain Remington I seem to recall. I will try the Remington again in one of the other .243's once I get them it might shoot in one of them or even both of them.

 However I am told that the P-H model 1000 really likes the Hornady 58 Grain V-Max ammo and shoots it into 1/2"-3/4" at 100 metres. We will see how I do with it  The Midland shoots a 100 grain Handload into just under 2" at 200 metres I will getting the prescription when I collect the rifle  it belongs to an internet friend.

As I said the BSA has been butchered by a previous owner  I have even begun to think about getting rid of it as I have seen another Majestic Featherweight with the BESA for sale but it's a 30-06, hmmm just checked and it's no longer listed so might have already sold, will need to phone to see. If I can find another good rifle with the BESA feature I will consider selling the 243 and replacing it as it might work out cheaper than having the stock bedding and barrel inletting repaired. The idiot hogged out the barrel channel to free float it and it looks a right eyesore. These Featherweights had a bedded barrel and the repair will probable entail fitted a shim or veneer of wood to bring the barrel channel back to what it's supposed to be.

However doing the seach brought up a nice looking even earlier "Hunter" model in 30-06 at a very attractive price ........... Oh dear 

[WL44]

Emmet has made some good points. Most 244's require a long action.

There is a bunch of opinions on barrel life - one of the 243's negatives. Apparently the 244/6mm Rem is "better", I can't really say. The 243 AI is "apparently" also better. In both instances despite more powder the shoulder angles etc. are apparently the reason. Again, I don't know....

If you like wildcats I'd do a search on the 6mm CM (Competition Match) of Joe Hendricks and speak to him. He is a top national level US competitor and an all round great guy. Maybe he can send you a reamer. He is getting great performance, barrel life and accuracy and did I say barrel life? from his. Tell him a guy in South Africa referred you... he was great to deal with.

Despite that, I'm lazy and components aren't that easy to get here, so after chatting with him I went for a straight 243. When this one is toast I'll maybe look at something else.... but I haven't got this license yet, so it'll be a few years before I need to make a change. A good 243 should give you 95gr high BC at 3100-3150 in a 26" tube at 1/2 MOA... what's not to like?

[Brithunter]

WL44 good luck with your new rifle once you get it that is  .

I am sorry to say that the .243 P-H model 1000 was returned as it had been severly abused by the previous owner who it seems even managed to break the bolt handle off. Once I got the rifle clean you could see the line of braze where it had been repaired. I did a variation tot eh licence and got a 25-06 in it's place. Still waiting ont he .243 Midland and I fear it too will drop by the wayside in the deal  the dealer who is holding it is getting a mite greedy.

[gunnut69]

I've used and own both calibers. First rifle I ever bought was a 243.. Low recoil and deer expire quite well. Have 4 just now 700BDL, Browning Auto Rifle, pre-64 M70, and post 64 M70. All do well though I seldom hunt with them any more. The 5mm has been around a little less time than the 243 but the worst problem was Remington made an error and the original twist rate was set at 1 in 12. This would not stabilize the 100 grain loads most used for deer sized critters. The Winchester folks envisioned the 243 as a dual purpose round and their 1 in 10 twist works well with both the 75 grain open points and the 100 grain deer slugs.. Their M722 was sold chambered in the 244Rem, (one better than the 243??). The outcry made remington change the twist rate really quick but shooters are a funny bunch and the 244 was marked as a varmit round only, even though I've measured at least 12 244's and only 1 had the 1 in 12 rate,,and I nbought it. I've heard it said that the slow twist M722 may be the rarest Reminton ever built.. Later in an effort to revitalize the 244 it was rnamed the 6mm Remington.. The effort failed..and only Remington still chambers the 6mmRem.. The 2 rounds are so close that no pratical difference exists. The 243 is shorter and likely has an advantage in an autoloading rifle.. The 6mm has an older style with more body taper and a longer neck, much like the 30-06. The neck gives the 6mm a supposed advantage for haolding bullets straight and the body taper lets it slick thru an action a bit smoother than the more abrupt 243. The standard twist for both the 6mm and the 243 is 1 in 10 though Remington rifles still carry the 1 in 9 twist they changed the 244 to use, in trying to rehab it's reputation.. My 700BDL a 243 has the 1 in 9 twist and do all Reminton rifles with the 243-6mm bore. I have never seen anyone provide any evidence that a shoulder angle will alter the speed with which a caliber will erode a throat or shoot out a barrel and believe such to be nonsense... I've never seen a poor shooting 243 or 6mm and there have been more than a few.. Even a M70 Ranger owned for a while until a better offer came along would easily produce sub 1 inch groups with huntiong bullets and common handloads. The M722 244 I still retain is a slow twist and with 75 grain Sierra HP bullets it is a little scary for a factory stock rifle. Coyotes stop in their tracks and bullets to the torso seldom exit.. Of course the 243's would likely produce similar results.. Both are great calibers and will probably be around for some time.. If more velocity and even flatter trajectories are desired wildcats abound. The 6mm-06 will give several hundred feet per second faster speeds and the 240 Gibbs even more. The 240 Weatherby is very similar in performance to the 5mm-06 while the Gibbs round is even quicker though requires fire forming. Of course use of these higher capacity cases WILL decrease barrel life.. Sorry for the tome..

[Oldshooter]

OK let me see if I can remember the 6mm/ 243 thing.

It seems that when the 6mm came out it had a 1 in 9 twist, and could not handle the heavier bullets. the 243 did and when Remington fixed it, it never caught up or so i am told.

I have a 6mm Remington from the 70's and it shoots lights out with 100 gr bullets. or 70 gr hollow points.

The "books" say 6mm has a wee bit better ballistics but the proof is in the pudding and the beauty is in the eye of the beholder and all that.

243 is as American as apple pie, Ford, and 30-30 

[yooper77]

The 6mm Remington came out first as the 244 Remington with a 1:12" rifling twist and later re-named to 6mm Remington with 1:9" rifling twist.  The 244 Remington couldn’t handle the heavier bullets that the 243 Winchester could handle, so it suffered.

The 243 Winchester is typically rifled with a 1:10" twist and mine handles any bullet from 70 to 100 grains with SUB MOA accuracy every time.

yooper77

[Oldshooter]

Correct me if I am wrong but Remington fixed the twist rate, but even then the 6 mm didn't catch on/ or keep up with the 243 in sales.

My 6 mm is a 70's era Remington and shoots heavies(100-105's as good as it does 75's and it will put those in the same jagged hole at 100 yds

[yooper77]

Correct me if I am wrong but Remington fixed the twist rate, but even then the 6 mm didn't catch on/ or keep up with the 243 in sales.

My 6 mm is a 70's era Remington and shoots heavies(100-105's as good as it does 75's and it will put those in the same jagged hole at 100 yds

Yes that is correct, you have the faster 1:9 rifling twist.  All similar cases are stellar performers and will never die. ( 7x57 Mauser, 257 Roberts and 6mm Remington)

yooper77

[Oldshooter]

Thanks, for the clarification. By the way I am still enjoying the 44 mag ammunition I purchased from you.

[yooper77]

Cool, did you punch paper, game or both?

What make of 44 Magnum?

yooper77