I am thinking of putting a rifle together based off the .243 Winchester case. Something lighter recoiling than my 6.5-284 and a true short action round. Two that intrigue me are the 6mm Competition Match and the Super LR.

Anyone have any experiences with either of these or any other match-inspired 6mm wildcats?

Thanks

6XC - based on the 22-250 instead of the 243. It's slightly shorter than 243-based wildcats, and therefore able to take advantage of the longer 105gr+ bullets without concern for COAL in a BDL/ADL internal box. It's inherently accurate as well, and was developed by David Tubb primarily for XTC competitions. I've had a number of 6mm wildcats, and it remains in my stable while the others have been sent down the road for various reasons.

For killing a 243 ackley is fun


Ran 85g Barnes at 3400 plus. It was a bad sob.

Gonna be a single shot and I don't want the 6XC- brass is very hard to find at most times.

I saw a European rifle yesterdY stamped .243 NOSLER. I don't have a clue what that animal is!

Not what you are asking about but if it is a single shot a 6-284 is a monster.

I have 3, a re-chambered 243 Montana, a Kreiger 12 twist on a 700, and a Stiller 10 twist Lilja.

They are fast and very accurate.

Necking down 6.5-284 brass in a single pass and Lapua makes brass.

70 grain Blitzkings and BT;s at 3800+ have to be seen to be believed and 100's at 3400 work very well on deer and antelope.
Stiller and my favorite hunting partner.

I have have several 6-284's and the case is just too large PLUS it isn't based on the 243.
I like the Ackley if you want to shoot factory, when necessary. The 6-47 L isn't based on the 243 but is easy to get to shoot really well provided the rifle is good.
The 6 SLR can have shoulder issues with Lapua cases.
The 6 Creedmoor is great but not strictly on the 243.
I would go Ackley or get a 6 on the Lapua or Creedmoor case.

Dennis, since you are talking single shot, options are many.

With the politics of today, importation of brass could stop as we learned in the mid 80's with Sako brass.

So, any case that is based on a 22/250 or 243 case would work well for you.

A custom 243 may sound boring, but they are Extremely accurate, and as a hunter the AI has no down side.

Some years ago, I built two custom 6/250 AI's and the speed with the 70's was at 3800 out of a 28" barrel with win 760, with match accuracy. If you look at the design on the 6/250 AI, it is very similar to some of the new cartridges.

There is also the 6mmBR-K

A 6BR reamer is used to go deeper to headspace as a 243.
I did the same concept with a 30BR reamer and headspaced it as a 308. Improved shoulder from 20 degrees to 30 degrees with less body taper.

From Accurate Shooter website:


Hot .243-Based Wildcats — The .243 BR-K and 6mm Super X

Gunsmith Mike Sosenko and long-time AccurateShooter Forum member John Adams have been using a modified .243 Winchester case with great success in Varmint Silhouette matches at the Pala Range in Southern California. Officially called the “.243 BR-K” (and informally dubbed the “6BR Long”), the wildcat is basically a .243 Winchester with less body taper and a 30-degree shoulder. The design essentially grafts a 6mmBR Norma “top end” to the .243 Winchester case. After fire-forming, Mike and John can reload this case using normal, unmodified 6BR neck-sizing and seater dies.

Compared to a .243 Winchester, the .243 BR-K’s body length is about .006″ longer, and the shoulder is about .0055″ wider. The main difference is the shoulder angle (30° vs. 20°), and the location of the neck-shoulder junction (“NSJ”). Based on reamer prints, the base to NSJ dimension is 1.718″ on the 6BR Long, compared to 1.804″ for the .243 Winchester. Neck length is a bit shorter because “the neck shrinks a little when the shoulder blows out” according to Sosenko. Check with Dave Kiff of Pacific Tool & Gauge for exact dimensions. Dave created the reamers for both the 6mm and 22-caliber versions of this wildcat. Ask for the “22 BR-K” or “.243 BR-K” reamer designs

That seems like a lot of work and expense to go through in order to say you are not shooting a 243 AI.

+1

Im playing with a 6.5 SLR for 1000 yard BR right now.
The problem....ie the problem for me is the 6mms are hard on barrels.A 243 or a case close to a 243 in 6mm is tons of fun.But require more tuning and time than I care for.
Now you take a 6.5 at the size of a 243 case.... say a 260 and 2000 rounds of decent accuracy can be had.
http://www.6mmar.com/65_SuperLR.php
dave

My last two 6.5-284 barrels lasted less than 800 rounds. I am seeing reports of 6mm CMs lasting 3000 and still being competitive. I really don't want a 243 AI. I might want to use my reamer for a repeater in the future should I like this and having plenty of experience with AIs, they don't feed in many rifles very well.

I can't find any match records showing anyone winning anything with a 243 AI either.

Right now I am leaning towards the super LR since it seems to be the easiest to make brass for. I bought 2000 243 cases today so I am not going to neck a creedmoor or 6.5x47L down.

Last season I ran a 6mm Dasher.
Ran 105g Berger hybrids at 3070 fps.
At 500 yards I have never seen a rifle shoot that well.Or come togeather as fast to find a load.
At 1000 yards in the two day shoot I shot back to back 29s.Which is just excellent.29 out of a possible 40.At 1100 rounds even though we scoped it and it didnt look all that bad.Im down to the low 20s if im lucky.
I played around with the load and came up with a dandy load at 500 yards that did very well.But running 100 fps slower than my 3070 load.You can just watch those bullets blow around in the wind.When the conditions are mild its ok.But in the middle of the afternoon.Its just not very effective..
I shoot against guys running just about everything.6x47s 6mm Dashers and Kevin Cram actually runs a 6CM with the 115g DTACs.Another guy runs a 6XC.They all can be made to shoot very well and there all nice and mild in the recoil department.Which makes the a pleasure to shoot.But if you run them up over 3000 none of them last very long.
A 6.5x47 at 2000 rounds can still win a match at 1000 yards.
No 6mm I know of can do that.

dave

Bullshit.....

I set the IBS 6 & 10 target 1000 yard agg records with a Dasher that had close to 2100 rounds on it, at 3075 fps......

Empirical evidence sucks.

Tanner

6mm-06 is one of the best 24 cal rounds you can build and the most over looked.

Why not just shoot a243? That is what I shoot. 105 berger hybrids 2950fps with lots of room to go up. Shoots lights out. My 9 year old hit the 6 inch by 12 inch steel at 500yds this morning. It shoots about.7 at 200yds. Brass are easy to get as well. Might be much less complicated.
.

Thats great.
I hope it keeps on keeping on for you.
But it is a different game.
At williamsport the guys will get the dashers out when its nice and calm and shoot bugholes.And theres nothing better for shooting little ones at 1000 than a well tuned dasher in dead conditions.But when the conditions kick up they put the dashers away and dig out the WSMs.
IBS matches are fun but offer limited shooting.Shoot a couple sighters.Wait for the 15 second call and squeeze off your last sighter round.Then run your 5 rounds.What? Shoot 8 or 10 rounds? And then spend the rest of the day cleaning after you hardly get it dirty.Thing should last 2000 rounds..
Stroking stuff is what IBS shooters are good at.
The Dasher is an excellent round but keeping it tuned is more work than its worth.The other problem is hitting targets and not knocking them over.Seen it.Really sucks hitting a coyote and it not falling over.Like I said its a different game.
...
I have seen the claims of boocoo barrel life for the 6mm CM.I have read it anyway.You pour that much powder down that small of a hole and bad things happen.The 6mmCM has a very short neck.I would pass.

dave

Don't try and pretend you can school me on Dashers and/or 1000 yard shooting.....

I tried to buy dies today and Redding wouldn't sell them for the 6mm Super LR- said I have to get them from Robert Whitley.

Dennis,have you give thought to a .22/243 with a fast twist?

No-the 22 bullets are poor ballistically and not the best killers.


I am now rethinking my reluctance to use the 6x47L as dies and brass are easily found as opposed to special dies that I have to buy from the guy who put his name on it.

Gotcha.

What's the matter with a plain Jane .243?

Dennis,

I have heard rumors that the .243 works real well when necked up to .30 caliber, but it doesn't seem to be what you're looking for. (Have heard it kicks pretty hard.... :-)

22/204 Ruger

That has 6x47 Lapua written all over it.

John

+1 ;-)

LMFAO

That sounds really good but since I already have several of those I guess that won't get the nod.

Neck is short and it makes it tough to switch between the various target bullets to get them close to the lands and still have idea bullet seating depth.

I like long necks and 30° shoulders

What about a 6mm-250?

.260 Remington or a 6.5 Panther.

Or even a .263 Express, which Ken Waters developed in 1956, the year after the .243 Winchester appeared, and a long time before Jim Carmichel came up with the 6.5 Panther. The .263 Express was also simply the .243 necked up to take 6.5mm bullets.

You mean the 6mm/.250 Savage Improved?

Ok, Google and Yahoo confirm that there is a 6.5 Panther, but they tell me nothing about it. What is the parent case??

I already have a 260 and 260 AI, I want a 6mm. The 6mm Creedmoor is probably a good one too.

I really like the 6creed so far. Like mule deer mentioned it's similar to 250AI case. Not as close as I thought it would be but similar for sure.

The 6.5 Panther was commercially adopted as the .260 Remington with very little changes.

Kaleb,

The 6.5 Creedmoor case is actually most similar to the .250 Savage RCBS Improved. The RCBS improved rounds used 28-degree shoulders instead of the 40-degree shoulders of Ackley Improved rounds, and 28 is very close to the 30-degree shoulder on the Creedmoor. It's close enough, in fact, for .22-250 brass to fire-from perfectly, with no trimming required, in a 6.5 Creedmoor chamber when using the Cream of Wheat method.

John,

I ran several fire-formed 250 Ackley cases through a 6.5 Creedmoor sizer, and out came usable cases. I also fired some 250 Savage ammo loaded with 87 grain HP-TNTs meant for the 250 Ackley in a 6.5 Creedmoor, and though accuracy was rather poor, nicely formed cases resulted. Funny thing......the rifle still shot minute of elk vitals at 100 yards sort of groups. So I suppose if a 6.5 Creed shooter found himself on a hunt with no ammo, and a supply of 250 Savage, he could continue onward!

Billy,

Handy to know! Especially if you're Travis.

Any guess on the BC of .25 TNT's from a 6.5 barrel?

Hee hee. The BC was probably not so great!

The 250 in a 6.5 test was probably not the smartest thing I’ve ever done. We’ll just add that one to a long list!

Just making sure this thread is at least partially about me.

Carry on.




Travis

...aren't they all.....in a loving way naturally..

The Ackley version kicks less though

Another magic Ackley characteristic!

Just goes to show a "new" cartridge may not actually be.

I wonder what Parker Otto would think about all this?

Their attributes are endless...

Build a 6MM Creedmoor. Factory brass is available from GA Precision for 62 cents each.

Drives 105gr bullets at 3100fps with ease. Perfect fit in a short action. Bullets will not seat below the neck/shoulder junction with room to spare in a short action.

Is there an advantage of the 6mm Creed over 6-6.5x47?

A little case capacity I guess.

The funny thing about the 6.5-47L case. Guys are running them to stupid velocities. Read a blog about one target shooter running his 6x47L to 3250 with 115 DTACs. With about 10 grains less capacity than a 243 which really can't even do that. He claims that the small primer cases handle pressure better. I can't imagine what his pressures are with that load but certainly far about 65,000 PSI.

I really wanted to do it on a 243 case but I am intrigued by the 6mm Creedmoor. Did not know brass existed.

I'll have to see the availability of reloading dies and order a reamer...

I got my 243 brass today and ordered a reamer (different project) and asked about the 6mm Creedmoor reamer. Was told 12-14 weeks out!

I will order some brass and seat a bullet to see what I need for freebore and neck. No reamer until then!

I ordered some dies. I will see how brass turns out before ordering a reamer.

From Kenny Jarrett

243 Catbird

68-70 gr. bullet ................... 4100 f.p.s.
85 gr. bullet ........................ 3800 f.p.s.
95 gr. Nosler Partition ......... 3500 f.p.s

.243 Improved

70 gr. Nosler bullet ......... 3650 f.p.s.
85 gr. Sierra Spitzer ......... 3450 f.p.s.

And this suggests???

If the catbird is that much faster than a 243 AI then it must be based on a much bigger case.

It's based on the 270 Winchester case, necked down and blown out with a 35 degree shoulder.

I know this cause I just read it on Jarretts website

It helps him sell more barrels.

Not sure how this enters the discussion

Sure you do. You want to discuss 243 based 6mm chamberings then someone comes along with a chambering that's the wrong action wrong case and who knows if he even read the original post?

That's true, what was I thinking.

Dennis, I don't think you were really clear in your opening post..."based off the 243 Winchester case" leaves a lot for interpretation

And what's the top three on your list now?

mid to high 500 bc is poor?

There is only one weight of bullet that has a decent BC and that is the 90 grain. It requires a 7 twist and if my rifle doesn't like that bullet there is no place to go. Besides, 22s foul easier (in my experience) than the bigger calibers. Just a lot of reasons I am not interested in a 22. The 6mm bullets are so much better for most of what I want to do.

Well a Catbird isn't possible to make from a 243 case. I was thinking the ones mentioned and possibly just a straight change to a 30° shoulder.

Because the CM has the short neck and the Super has proprietary everything, I ordered dies and brass for 6x47L instead. Should lose a few fps in velocity but hopefully pick up a little advantage in accuracy with the good brass for that parent case and the small primer.