6mm recommendations on the 243 case?

[COMPRESSEDLOAD]

Hi,

My first post here; I've read and learnt a lot. Thank you.

I'm looking to build a 6mm with the following requirements:

3300 fps with 115gr DTACs
Barrel life 10 000 rounds
1/8th min accuracy....

Hmmm... Okay, seriously I wanted better barrel life and more stable brass than the 243 Win with maybe less of a doughnut issue. I'm happy with 243 or even slightly less performance. I liked the idea of a bit more capacity and slower powders to achieve the barrel life. Were it not for barrel life I'd probably not be too unhappy with the 243 Win.

I wanted to be able to use 243 brass,due to availability here in S.Africa) and the ability to use standard dies,be they 243, 6 BR or whatever). I need to be able to buy a reamer so that I can set the barrel back from time to time as needed,unless this is a dumb idea).

I've seen the 6mm HLS mentioned,no idea what it really is), 6mm Comp Match,found more on that, but still not a bunch), 243 BR-K,looks like a great alternative), 6mm Super X,no idea what that is really).

I'd like to shoot 85gr to 95gr VLDs. Rifle would be used for hunting and field shooting matches out to 400-500 yards.

Please give me any comments on these or other suggestions as to chamberings. What's to like, what not, what dies do they use and any recommednations on twists for this rifle.

I've already got the action - Rem 700 SA and the stock,McM Marksman).

Thanks for sharing your ideas.

WL

 

[treeman]

I saw a cartridge on this sight some where that uses the 243 case but has the neck and shoulder of the 6mmbr norma. with the 30 deg. shoulder the brass would more stable and need to be trimed a lot less. if i find where i saw it i'll post again. it looks like just what you are looking for. the 6-6.5X47 would work also useing 243 brass but you would have to shorten it some. good luck and goodn shooting.______treeman

 

[COMPRESSEDLOAD]

Thanks Treeman. That's the 243 BR-K as I recall. Basically a 6 BR top-end on a 243 lower!

 

[Raptor]

The 6MMsuperX is a 243 case with a 6BRneck and shoulder. Its a really nice case and a nice round. It uses the same loading data as the 243s but has a longer neck and the 30degree shoulder. They believe this promotes better barrel life.

Its easy to load for an the cases are very easy to make. When fire forming the case it will shoot just as well as a fire formed case. ITs a great round!!

 

[MarkS]

WL,

The 243 AI would be the best case to fit your needs. Factory dies, easy case forming. Any of the others you are looking at custom dies. But, barrel life is only some much better. If you are not going over 95gr bullets, a 10 tw would be fine. A 243AI held the IBS 1000 yds 6 target group agg for 5 years shooting 95 gr Bergers.

My round of choice would be a 10tw 6BR, Lapua brass is the brass made bar none). A 6BR will run close to the speed of a 243 with 8 to 10 gr less powder. If you want a little more speed go to a Dasher. you can still get factory dies.

Mark Schronce

 

[rpl6cm]

You should really look at the 6cm,competition match). I am shooting the 115 dtac at 2950fps with .323moa results.The brass is readily available,you don't have to turn necks, all you have to do is fireform. The shoulder is bumped out and the neck angle is 30 degrees. Joe Hendricks designed the cartridge. Joe is a NRA highpower shooter with lots of successful experience. Contact him and he will send you pages and pages of reloading info and helpful advice. Good luck

 

[teele1]

+1 on the 6CM I've been shooting mine for almost two years and love it. Joe is great with sharing information on this cartridge.
Shoot Strait teele1

 

[COMPRESSEDLOAD]

Thanks for the replies and suggestions.

I don't know how I missed the lengthy discussion on the Super-X - found a great thread on it and looked it all over.

I like the 243 BR-K; it uses 6mm BR sizer and seater. Custom dies for sizing the base if need be. I also like the 6mm CM and 6mm Super-X.

I'm weighing them up and it's likely to be between those. Thanks for the suggestions.

WL

 

[jadams]

COMPRESSEDLOAD

It's true the .243 BRK uses the standard 6Br. neck sizing die and it also uses the standard 6Br. seating die.
There are quite a number of us using the cartridge here in So.Ca.
with great sucsess. We have them with both the .262" and .274" necks.

My personal guns have the .274" necks. It is my personal experiace has been that after a number of rounds have been fired the brass thickens in the neck area causing me to turn the brass .001". I
originally wanted a no-turn neck cartridge. If you chose to use the .243 BRK. I would like to recommend that you order your reamer with a .275" neck.
Our powder of choise is Re-22 Start with 44 grains and have fun !
John

 

[1shot]

I have been shooting the 6 Super X for a full season now and it will give you match winning accuracy everytime if you do your part. In the last two matches, Ky. state 1,000 yd championship and a 3x600 NRA match, the rifle gave me 3 back to back 197 out of 200 matches. The dropped 3 points were totally the fault of the nut behind the trigger. I drive either Berger VLD's or DTAC's at 3023 fps with no pressure issues and W-W brass life is supurb within that range. Contact Robert Whitley an he will fill you in on the finer points of the cartridge. I know it's working for me!
I hope this helps,
Lloyd

 

[COMPRESSEDLOAD]

Thanks to all who contributed to this thread.

I've had replies here and PM's too.

I still like the 3 chamberings I identified earlier and I've had good feedback on all of them, although I also received some good arguments for the standard 243...

I'll certainly let you know which way I go in the end.

Wim

 

[p17enfeild]

hi boet !
hay i grow in it the transvaal! here what shoot in england

it a 243 with 30deg shoulder and .460 at shouler body juction !
it uses stander 6br die's back out of press a bit so my neck lenght is same as .243 wim but shoulder and boady taper are same as 6br, it shoots good with heavy bullet 100gr at 3300 easy if you want ill email the reammer print !or photos laod data ect!

s385 is good power to start with but you my need slower to get top speeds,

you need a 9 twist or farer but not more than 7.5 twist

my rifle as par nor barrel on it and last year when i was over in sa i so that 'die skiet wenkel' in bloomfontain was importing them ? only mention this as mine as 1000 round though now and no sign of wear when i bore scoped it!

ps i miss s335 nothing here is as good

 

[p17enfeild]

good luck with the police there here that it harded and hard to get your licinse sorted

as for setting back your barrel it may not shoot ass good as a fully new one but well better than a worn throut

 

[rcw3]

6mm Super X uses 6XC dies,sizing die held off the shell holder .120"). I have never needed to use anything more to size the cases despite 10+ firings of the brass. Attached is a reamer drawing for the 6mm Super X,throated for the DTAC and Berger 115's - works well with Berger 108's, Sierra 107's, Lapua 105's too). I neck turn to .2715" to .272" with this reamer. If you use Winchester brand 243 brass as your base brass without neck turning, you would have a reamer set up with a .276 neck.

Robert Whitley

 

[rcw3]

Here's a picture of a 243Win,left) vs a 6mm Super X,center) vs a 6XC,right). All I can say is the 6mm Super X has been good to me and I have shot many a clean in 600 yard high power matches with it with either DTAC 115's or Berger 115's.

Robert Whitley

 

[HPMike800]

Robert:

How is barrel life with the SuperX? What's your load with Brg115's? Can you get say 3050fps easily with H4831?

Mike

 

[rcw3]

Mike

You can get 3050 fps with H4831SC and the 115's with no problem, I did it in testing multiple times, but to me that also does not mean anything because I shoot loads where they are the most consistent and accurate over a 22+ shot string, and I have never,I repeat never) found any of the 6mm cartridges I have worked with to shoot the 115's for 22+ shots straight to stay consistent, tight and accurate the whole way at 3050 fps. I have tried 115's in the 243Win, the 6CM, the 6mm Super X, the 6XC, the 6/6.5 x 47 Lapua and none of them ever stayed consistent and tight for 22 shots straight with the 115's at that speed. Most of the time with all the 6mm cartridges, if you get the 115's much over 2975 fps, they won't hold tight for 22 + shots straight. Now if you're a bench rest shooter and you only need to do a few sighters then 5 or 10 shots for record, you can run 3050 fps or more and the groups will likely hold tight during your string, but not when you need to go 22+ shots straight in a row with no break.

Now I am sure some shooter can get on here an say his rifle/cartridge can do it and then some, but I have shot a lot of different 6mm's and done a lot of testing with a lot of different powders, moly and non-moly bullets, and I keep coming back to the words "consistent accuracy" as what is important,at least for the discipline I shoot), and I don't find the "consistent accuracy",for 22+ shots straight) at those higher velocities.

Robert Whitley

 

[COMPRESSEDLOAD]

Thanks again for all of the comments and input.

I've had some really good advice and some convincing arguments that the good old 243 will do what I want and get the barrel life with approporaite cleaning and loads.

This may be where I start up - nothing exciting at all! It would certainly make my life easier over here if I could get where I want to with that. If I was disappointed I may be able to rechamber later.

I'll let you all know where I end up. This is probably standing over to the new year now.

WL

 

[Dgd6mm]

rcw3, what's the barrel life with accuracy,and the powder you are useing? thanks

 

[COMPRESSEDLOAD]

Thanks again for the replies to this thread. Making a little progress and will let you all know how I go.