Author Topic: Best .243/6mm cartridge? (Read 4171 times)

jkpq45 · « **on:** August 24, 2012, 09:08:36 AM »

Looking for a .243/6mm cartridge which has reasonably long barrel life (2000 rounds?) while also getting decent performance from light- and mid-weight bullets (50-60 grainers at 3700+ FPS and 100 grainers at 2700+ FPS).

The barrel's been donated from an old Browning BRR--currently chambered in 243 Winchester. Should I change cartridges (the WSSM is calling....) or just leave it alone?

THANKS!
jkpq45

jkpq45 · « **Reply #1 on:** August 24, 2012, 09:11:21 AM »

Forgot to mention--thinking also of:

1. 6mm-06; have brass, have some dies.
2. 6x54R; have brass, can fit to a Mosin, what's not to like?

jkpq45 · « **Reply #2 on:** August 24, 2012, 09:28:07 AM »

Looks like I might be able to get 55gn bullet to about 3200 FPS from 6mm Bullberry (necked down 30-30). Not a lot of advantage in a break-action--but that kind of performance from a 6mm in lever-action would be fun.

jkpq45 · « **Reply #3 on:** August 24, 2012, 10:37:45 AM »

More research:

240 Gibbs is a better performer than 6mm-06. 55-grain Nosler BTs at 4,310 FPS. Remember how I said I only needed ~2000 rounds out of this sucka?

gypsyman · « **Reply #4 on:** August 25, 2012, 07:43:59 PM »

I've always been fond of my 6mm A.I. gypsyman

IOWA DON · « **Reply #5 on:** August 26, 2012, 11:06:36 AM »

I've got two custom 6MM-06 barrels for Thompson-Center TCR (single shot hammerless switch barrel) rifles. One is 29 inches long and has a 1-in-12 twist for light bullets. It shoots 70-grain Nosler Ballistic Tips at 3,900 fps. The other is 26 inches long with a 1-in-8.5 twist for heavy bullets. It shoots Berger 105-grain VLD's at close to 3,300 fps. With the 70-grain Ballistic tips at 3,900 fps one can zero the scope for 300 yards for a flat shooting coyote rifle. The 105-grain VLD's work well on our Iowa does (can't shoot bucks with a rifle in Iowa). I've shot over 30 deer with the 105-grain VLD's and 12 were over 300 yards and some of those were a little more or less than 400 yards, and the distances were measured with a laser range-finder. I don't target shoot with the 6MM-06's so barrel life doesn't matter. I can shoot lots of deer and coyotes before getting 1,000 rounds through the barrels.

Catfish · « **Reply #6 on:** August 26, 2012, 03:34:18 PM »

I have a couple of 6-284 barrel that shoot the 70 gr. bullets very well. They are both Savage barrels, but neather does well with 105 of 107 gr. bullets, which is what I want to shoot. If interested, I would sell one of them. The 284 case is the same volume as the 06 case.

va243hntr · « **Reply #7 on:** August 30, 2012, 07:26:05 AM »

How about just a plain ol 243AI easy to fireform good brass life and can find brass anywhere you could look at a 240 weatherby mag

jeepmann1948 · « **Reply #8 on:** August 31, 2012, 01:46:35 AM »

I built a 6mm ACK on a 700 Remington action.Using 70gr Sierra bullets and a very generous load of H414 it shoots a 5 round group at 100 yards into a .180 group. It is a very fast accurate rifle that kills like the hammer of Thor.Is it any better than others? This is subjective to the owner. I also have some very accurate 243 Win and another 700 Remington in regular 6mm.All of them have been "tuned" and are also very accurate, although not as good as the 6mm Ack.Considering the options in a 6mm wildcat the 6mm Ack is a good option due to the availability of brass and case forming.using proper care and reloading choices it will last as long as any of the "hot rods".
Good Luck
George

244Ack · « **Reply #9 on:** September 02, 2012, 09:05:20 AM »

Another vote for the 6mm Ackley. Been shooting this cartridge for 25 years and love it

AWS · « **Reply #10 on:** September 03, 2012, 07:00:52 PM »

If you have a small boltfaced donnor a 6mm-204 should do what your asking. Mine will do 3600-3700fps with 55gr. bullets out of a 24" barrel, haven't loaded any heavie as this is just a coyote rig. My 25-204 will do 2800fps with 100gr out of a 22" barrel.

lgm270 · « **Reply #11 on:** September 13, 2012, 07:58:28 AM »

Quote from: jeepmann1948 on August 31, 2012, 01:46:35 AM

I built a 6mm ACK on a 700 Remington action.Using 70gr Sierra bullets and a very generous load of H414 it shoots a 5 round group at 100 yards into a .180 group. It is a very fast accurate rifle that kills like the hammer of Thor.Is it any better than others? This is subjective to the owner. I also have some very accurate 243 Win and another 700 Remington in regular 6mm.All of them have been "tuned" and are also very accurate, although not as good as the 6mm Ack.Considering the options in a 6mm wildcat the 6mm Ack is a good option due to the availability of brass and case forming.using proper care and reloading choices it will last as long as any of the "hot rods".
Good Luck
George

What do you hunt with it?

iiranger · « **Reply #12 on:** September 15, 2012, 08:31:46 AM »

When I read/studied Mr. Ackley's two volume set of books, the cartridge that "blew me away" was the .25/35 Ackley Improved. 60 grainers at 3800. 75's at 3600... My first point is that there are many versions of the 6mm/.30/30 out there that should preform about the same. Eabco.com works with one. I got the wild idea that this was only in single shots like the 1885. I wrote to Mr. Ackley, a fine and helpful gentleman, and he replied, no he got these results right along in 94 Winchesters.

My other favorites, 6mm International. (6mm/.250 Savage, more commonly made by necking up the .22.250 brass today I suspect.) Last I looked, Remington still offered it in the 40X. I guess it ruled the target range in the days before the .222. Now this might get you the 2,000 rounds you seek. Might.

And, of course, the hot and lately, 6mm/.284 with the short powder column and the sharp shoulder of "late.". My gunsmith buddy built several dozen. He said that he no more than got the barrel screwed in (Mausers mainly) and took it to test and someone was so impressed they would shove money at him and take the gun... and he would build another. I watched as he worked with his last. Dipped the case full of IMR 4350 and seated a lighter bullet and got tiny groups. Chronyed one load (70 grain Hornadys) and got 3900 fps with acceptable pressures. He miked heads...

He told a story of a friend, also a 6/284 nut, who loaned his rifle out for load development... Many hundred rounds later it came back. He looked down the barrel and there was visible wear for 12 inches or more. He thought "new barrel." BUT he took it to the range one more time first. What had been 1/2 inch groups was now 3/4 inch groups and he skipped the new barrel. You? Luck. Happy trails.

hedgehoghunter · « **Reply #13 on:** December 08, 2012, 08:12:09 AM »

Hello guy . I personally like the 6 x 47 Lapua ,6 Dasher , 6br I've heard some good on the 6CM but never owned 1. Good luck with what ever you do .

Catfish · « **Reply #14 on:** December 10, 2012, 01:48:12 AM »

I don`t know where you live, but I`m about 35 mi. N. of Dayton OH. and if your close enough I have reamers for for the 6-284 and 6mm on the 300 WSM case if your looking a for barrel burner.

jeepmann1948 · « **Reply #15 on:** December 13, 2012, 12:51:52 PM »

lgm270,
Just noticed the question you posted way back in September. Sorry I was not trying to ignore you.
I have used mine for varmints and deer with excellent results.The 70 gr bullets really ruin a critters day very quickly.You can put one in a deer's ear and not leave an entrance hole but the exit hole is a different story. (too gruesome for pics or description). gophers, p dogs and the like just become red mist.
George

jkpq45 · « **Reply #16 on:** December 14, 2012, 05:48:47 AM »

Catfish, thanks for the offer--sure would be nice if I were in OH, I could be shootin' by Sunday afternoon.

I better get on the lathe and start makin' my reamer.

crash87 · « **Reply #17 on:** December 15, 2012, 10:38:47 AM »

Quote from: AWS on September 03, 2012, 07:00:52 PM

If you have a small boltfaced donnor a 6mm-204 should do what your asking. Mine will do 3600-3700fps with 55gr. bullets out of a 24" barrel, haven't loaded any heavie as this is just a coyote rig. My 25-204 will do 2800fps with 100gr out of a 22" barrel.

Where or who, did you get your 6mm-204 dies?
thanks
Crash87

jeepmann1948 · « **Reply #18 on:** December 16, 2012, 01:10:25 AM »

6mm-204 is the same as 6x47 a at one time popular benchrest cartridge, like the 204 it is based on the 222 Remington Mag case . Another good one is the 6x45 . It is based on the 223 case. one pass thru a resizing die and it is ready to load.Both are inherently accurate loads with easy to make cases.
Good Luck
George

crash87 · « **Reply #19 on:** December 16, 2012, 02:41:44 AM »

Quote from: jeepmann1948 on December 16, 2012, 01:10:25 AM

6mm-204 is the same as 6x47 a at one time popular benchrest cartridge, like the 204 it is based on the 222 Remington Mag case . Another good one is the 6x45 . It is based on the 223 case. one pass thru a resizing die and it is ready to load.Both are inherently accurate loads with easy to make cases.
Good Luck
George

If only it was that easy or true, which of course, it is not! While it is true the 2 are based on the 222 magnum case and there both 6mm that is where the similarity ends. The 6x47 still shares the same shoulder angle of 23 degrees, while the the 6X204 is 30 degrees. But the big difference comes with the base to shoulder measurement, is longer in favor of the 204 by .075". Body taper is also reduced. So basically the 6mmX204 can be considered a 6X47 Improved, but "the same" they are not.
Crash87

jeepmann1948 · « **Reply #20 on:** December 16, 2012, 07:37:47 AM »

I wonder how much real world difference there is in ballastics?

crash87 · « **Reply #21 on:** December 16, 2012, 01:18:49 PM »

According to the 2008 hodgdon manual for the 6X47, a pressure tested load, with a max charge of BL-C(2) will yield 2935fps with a Speer 80gr SP and a 23.5" barrel.
In the 2012 hodgdon manual, an article written on the 6mmX204 and a non tested load, with a charge of IMR 4064 yielded 2950fps with a 80gr Deep Curl and a 22" barrel.
While not really a good comparison, it does give one an idea of the 2. While adding 1 1/2" to the 6mmX204 will give it the edge in velocity, it would only matter on paper as not to make a whole lot of difference in the field. While brass is, available, for the 222 magnum, 204 Ruger is more prevalent by far.
Minor difference for sure. Its all what one wants, as to the decision of what is better, at least in the shooters mind.
Crash87

BBF · « **Reply #22 on:** December 17, 2012, 07:52:50 AM »

Quote from: va243hntr on August 30, 2012, 07:26:05 AM

How about just a plain ol 243AI easy to fireform good brass life and can find brass anywhere you could look at a 240 weatherby mag

Nix on the 240 Wby unless you want the chamber to be cut back, way back !!

jedman · « **Reply #23 on:** December 20, 2012, 12:20:59 PM »

.243 Winchester and call it a day ! Jed

Couger · « **Reply #24 on:** March 01, 2013, 06:23:19 AM »

Quote from: gypsyman

..... always been fond of my 6mm A.I.

Yup. Or just stick with the standard 6mm! Both excell at shootin' vermitts and deers!

Also Barnsness and Ken Waters (both gun writers) attest that the 6mm's [more consistently, as in accurately] handle MAX pressures better than the .243W.

As for the WSSM, is that round even going to live to the next few years? If not why bother with that brass?

jkpq45 · « **Reply #25 on:** March 01, 2013, 07:26:48 AM »

During further research, I determined that the best performance, non-belted-magnum round was 240 Gibbs.

Pros:
Speed
Bullet weights available
Brass forever! (based on 30-06)

Cons:
Short barrel life

Couger · « **Reply #26 on:** March 02, 2013, 02:39:56 AM »

You might do better to choose a cartridge that wasn't so "over-bore," and better balanced with [amount of] powder to caliber!

This thread originally was titled "best .243/6mm catridge?"

Where I live is a gun shop, "Benchmark Barrels," who build their own barrels and even have several world-records under their belt/s.

And talking with several of the fellows who work there, the rounds they shoot include ones like the

.250Ackley,
6mm International,
6.5 Grendal, etc

but most of them are especially impressed with the 6X47 Lapua, even for use as a long rong target / varmint round!

And it YES it dispatches deer-size game well too.

This round easily fits in a M700 SHORT action and has a .473" diameter rim, and is extremely "efficient" (capacity to bore). It rivals the .243W and 6mm Rem in velocities with usual varmint /benchrest weight bullets (70-80grainers at 3200-3400+ fps!),

and cases have SMALL RIFLE-size primers - which is bound to be helpful as well in those roles.

"Accurate rifles" are the ones I find that interesting and impressive!

ThomTender · « **Reply #27 on:** March 05, 2013, 01:34:44 PM »

I had a 240 Gibbs in the 1970/1980's and it was the flatest shooting rifle I ever shot or had. I formed the cases from 25/06 rem. very easy. Used the surplus hodgdon 4831 powder,Sure am sorry I sold it. Used 87 gr sierra bullets both for chucks and deer. It was awesome. Got this idea to move to FL. and thought I would have no need for a rifle of this type. Again I say Boy am I sorry I sold it. Was built on a surplus Mauser 98 action ,, Douglas 28" barrel and a Fajen stock.

Ladobe · « **Reply #28 on:** March 28, 2013, 07:27:23 AM »

My favorites... 6 Super Bower, 243WSSM.

mcwoodduck · « **Reply #29 on:** March 28, 2013, 08:00:29 AM »

I think it is hard ot say best, in this case.
Best is going to change based on a few things.
1) the action, can it work with the caliber? A short action 700 is not going to work with your 6mm-06 other than as a single shot.
2) you mentioned a Mosan action, that would exclude a lot of options. As the action can not take the pressures of many of the ctgs mentioned.
and I gues it does not matter what you ae going to use it for, the speed required with the bullet weight is going to dictate the use.
I think your questions should be, what CTG is going to be best for the action you are planning on using, what happened to the BLR? Modifying the magazine could result reuse of that action.