• Watch Out for Scammers!

    We've now added a color code for all accounts. Orange accounts are new members, Blue are full members, and Green are Supporters. If you get a message about a sale from an orange account, make sure you pay attention before sending any money!

Which 6mm?

R

rg1911

Gunny Sergeant
Supporter
Full Member
Minuteman
Oct 24, 2012
845
339
71
Laramie, Wyoming
I have a Krieger 6mm, 1-8 twist barrel on order and am looking for a good 6mm cartridge for which to chamber it. I would like it to be useful (as in hunting prairie rats and for our 600-yard sniper matches) out to at least 600 yards, and preferably further. This will be on a switch-barrel Remington 700 action.

At our monthly sniper match, one shooter said he uses the 6BR with 107-grain bullets for 600-yard IBS matches and also out to 1,000 yards. I have a 6BR Improved, but it's 1-10 twist, so 87-grain VMax are the heaviest I use with it. Plus, although it's accurate, my load is on the ragged edge. I don't expect that barrel to last much longer.

Another very accomplished shooter at the match is getting a new barrel chambered in 6mm Creedmoor because he said he won't have to do anything special to the brass.

I contemplated the 6X45, but based on my experience with my poor overworked 6BR, I would prefer more capacity.

Note that I'm not thinking of the 6.5X47 Lapua. I already have a 6.5-.284 and a .260 Remington.

This seems to leave the 6 Creedmoor, the 6X47 Lapua, the 6mmXC, and, come to think of it, the venerable .243.

Is there a reasonably clear winner here? (I don't mind prepping brass, and I'm not trying to start a religious war.)

Many thanks,
Richard
 
I shot the 6x(older 6xc) for a few years. I loved it and i still would be if I didn't need the cash for stupid car tires. The 6xc is really accurate and good beyond 1000 yards. I shot my 6x at 1000 yard matches with good results also. The 6xc has factory ammo from David tubb and dies but the downside is they are expensive.

The .243 is another great cartridge and when I go back to shooting a 6mm, that's what I'll go with because the dies, brass and factory ammo are readily accessible and not to expensive. Not to mention, it's an accurate fast cartridge shooting 100 fps faster then a 6xc but at the cost of barrel life. Plenty of people will argue that you can get good barrel life out of a .243, you just need to push them to 3000 fps and beyond and you're fine.

I like the idea of a cartridge that's easily acquired in case of emergencies.
 
There are so many good ones.
6mm Rem
6mm SLR
6 Crusader
6x47L
244 H&H, ok just kidding on that one! But I have always wanted to try it.
 
There are so many good ones.
6mm Rem
6mm SLR
6 Crusader
6x47L
244 H&H, ok just kidding on that one! But I have always wanted to try it.
 
All of the 6mm chamberings shoot well. 243, 6xc, 6x47, 6cm. Everybody pretty well uses the same bullet weight class. The shorter cases seem to be a little more efficient when it comes to powder use, but I'm with Anthony, every part of the 243 is cheaper and easier to get. And they all accomplish the same thing, push a 105 at 3000 to 3200 fps, But the 243 probably with a little less pressure since the capacity is greater. Either way they are great rounds, a little hard on throats but still lots of fun to shoot.
 
Why not another 6BR Improved, just with your 8 twist? You've already got all the tooling, brass and other particulars, save for the bullets?

An improved 6BR will have plenty of horsepower for 600+ yards.

No doubt though, the other cartridges mentioned will get out to 1000 yards with more authority. Amongst them, I can't think of any particularly compelling reason to not choose the simple 243. My last choice would be 6mm Creedmoor on account of the recent rash of complaints regarding loose primer pockets after a shot or two.
 
I went creedmoor. Glad I did. Any listed would work well for your stated use.
 
I like the 6x47 more than the Creedmore just because of the quality of brass.

However I am still using a 6 Competition Match. I can easily push a 115 along at 3,000-3,100 with no pressure.
 
I have a 243 with a 20" barrel that I am getting 3000 fps with the 105 berger. It has 750 rounds down it and I'm using H4350. When that barrel goes south I'm going to rebarrel with a 22" straight jacket barrel. Been wanting to try one of those. Should be a good prs setup and nice and light.
 
HodgdonExtreme said:
Why not another 6BR Improved, just with your 8 twist? You've already got all the tooling, brass and other particulars, save for the bullets?

An improved 6BR will have plenty of horsepower for 600+ yards.

No doubt though, the other cartridges mentioned will get out to 1000 yards with more authority. Amongst them, I can't think of any particularly compelling reason to not choose the simple 243. My last choice would be 6mm Creedmoor on account of the recent rash of complaints regarding loose primer pockets after a shot or two.
Click to expand...

My 6br with an 8 twist will do 700 yards easy with GREAT
accuracy, I have over 30 fires on my lapua brass. still running great 105 Bergers at 2860.
You said you already have a 260?
 
I'm in with the 243 crowd. All the reasoning mentioned above, I planned a 243ai but very little advantage over standard 243, it would take a fair amount of extra work. I'm doing it in a savage 10 action with a lothar walther barrel. Should be a good tactical comp gun. 243 win for my vote, good luck
 
Some have feeding problems with the 6BR and 6BR imp. I do not in my Borden action repeater. It feeds fine. Just a thought.
 
Why no love for the 243AI? I see so many say it ain't worth the trouble, but there really isn't much trouble. Mine loves 243Win factory ammo, and shooting it once fire-forms the brass for 243AI reloads, where's the trouble? Add to that, cases don't stretch nearly as much, and I can run it faster than a factory 243 if I want.
Nothing wrong with a 243Win, it has been around forever and ammo and components are plentiful.
The others have their draw (6x47 having small rifle primers is a big plus) but components can be an issue.

If I had it all to do again, it'd be a toss-up, I doubt you would be disappointed in any of the mentioned options.

(Built my 243AI on a Tikka T3 action, some have complained of feeding problems with the 40 degree shoulders; all T3s are long action, so I have no issues at all with feeding in mine. On a remmy SA, it might be different.)
 
Rancid, specifics about ur rig. I am having a 243ai built on a tikka, wearing a 24" Krieger1-8. Plan to run 105 hybrids at 3100ish.
 
If you want the longest brass life and most of the benefits you already appreciate about your 6br improved then 6x47L is the answer.

In a longer barrel 3150 fps with 105's is doable and 6x47L feeds like butter out of AI mags.
 
243AI makes over-cased 243Win even bigger, doesn't fix the short neck, but it does fix the body taper and shoulder angle.

SLR fixes all of the above - it makes a perfect (to modern understanding) 308-based 6mm cartridge.

6mm Creedmoor might be theoretically even better - but it is based on proprietary brass.
 
My smith has a 243ai reamer, i might try a slr sometime. The cost of a reamer would have to be offset by several worn out 243ai barrels.
 
Love my 1 in 8 br but i would go 6 xc for 600 plus. 600 is starting to stretch the br but it will do it
 
6.5labs said:
Love my 1 in 8 br but i would go 6 xc for 600 plus. 600 is starting to stretch the br but it will do it
Click to expand...

I disagree. Did you see where 1911 resides?
we have an average D.A. of 6000. in the summer it will be at 9000
them little 105 pills fly up here.
As far as the 6x47 goes, my shooting buddy rebarrels his about every 1700 rounds!
shoots lights out though.
 
6SLR does not modify or improve the taper of 243 as 243ai does. That notwithstanding, the 243/260/708/308 family already has little taper to begin with.

I personally think the 6SLR is ideal for PRS matches where 3150fps is generally the speed limit. SLR achieves 3150 with ease. The x47, XC and Creedmoor will also go 3150, but must be pushed harder. The x47 brass can obviously handle the pressure, but some Creedmoor shooters are complaining their brass is going to hell. Seems it is much happier at 3100.

243 matches (in fact ever so slightly exceeds) the SLR in case capacity. Really, there is no appreciable difference between the two, except the SLR is way cooler with the 30° shoulder and long neck.

I've no hate for Ackley cartridges, but 243ai is really unneeded for most purposes. 243 easily bests PRS speed limits and flings little varmint bullets at explosive speeds. Sure, the Ackley will do it faster, but you'll pay for it in barrels. Worth it? Maybe. Your call.

ETA: A nice benefit to the 243ai (or 6mm Comp Match) though, is being able go 3100+ with 105s using H1000, something the others can't do. That will help make the barrel last longer for sure.
 
Last edited:
I'm shooting a good old fashioned 6mm Rem in a 1:8 twist. Shoots the 105gr A-max's very well and it's very easy to push them over 3k fps. Great brass life and nothing fancy needed to reload. They also have a pretty long neck.
 
I use a 6SLR and it works hard for me. At 3100fps it's only 6.7 mil vertical at 1000 and still supersonic at 1500 yds. This is with 105 hybrid bullets which use a 1:8 twist. If use use a 7.7 twist then you can use the heavier 115 DTAC bullets. I don't think they will fit in a regular magazine.
There are lots of good choices in 243/6mm. I only have experience in the 6slr. Let us know what you end up with.
 
I vote old school 243 I'm getting avg over 20rnds @ 3050 with 105 and 100v. def could get higher if I wanted
 
6mm has a lot of flavors and many of them are great. But at this time for me it's 6 CM, works great in a gas gun, brass is available, very affordable and the quality so far seems to be great too!
 
I love my 6-284L with 105 vlds. It's an absolute laser and a critter killin fool. Only trouble is barrel life. I'm running 51gr of rel22 and I pushing the 105 vlds at 3300fps out of a 24in barrel
 
HodgdonExtreme said:
Why not another 6BR Improved, just with your 8 twist? You've already got all the tooling, brass and other particulars, save for the bullets?

An improved 6BR will have plenty of horsepower for 600+ yards.

No doubt though, the other cartridges mentioned will get out to 1000 yards with more authority. Amongst them, I can't think of any particularly compelling reason to not choose the simple 243. My last choice would be 6mm Creedmoor on account of the recent rash of complaints regarding loose primer pockets after a shot or two.
Click to expand...

HodgdonExtreme said:
6SLR does not modify or improve the taper of 243 as 243ai does. That notwithstanding, the 243/260/708/308 family already has little taper to begin with.

I personally think the 6SLR is ideal for PRS matches where 3150fps is generally the speed limit. SLR achieves 3150 with ease. The x47, XC and Creedmoor will also go 3150, but must be pushed harder. The x47 brass can obviously handle the pressure, but some Creedmoor shooters are complaining their brass is going to hell. Seems it is much happier at 3100.

243 matches (in fact ever so slightly exceeds) the SLR in case capacity. Really, there is no appreciable difference between the two, except the SLR is way cooler with the 30° shoulder and long neck.

I've no hate for Ackley cartridges, but 243ai is really unneeded for most purposes. 243 easily bests PRS speed limits and flings little varmint bullets at explosive speeds. Sure, the Ackley will do it faster, but you'll pay for it in barrels. Worth it? Maybe. Your call.

ETA: A nice benefit to the 243ai (or 6mm Comp Match) though, is being able go 3100+ with 105s using H1000, something the others can't do. That will help make the barrel last longer for sure.
Click to expand...

Internet warriors, Assemble!

Any personal experience with the loose primer pockets? Some deeper research will show that running any cartridge above the recommended pressure will destroy the brass. I haven't destroyed any 6.5 Creedmoor brass yet so I can't say I have the loose primer pocket problem.

Also don't forget to mention that 6 Competition Match and H1000 is for 28" and longer barrels.
 
How's the accuracy of the 243 compared with the 6 creedmoor and are there any seating issues with 105 Berger hybrids. Also, is the barrel life similar?
 
peaceatwar said:
Internet warriors, Assemble!
Click to expand...

What is that supposed to mean?

peaceatwar said:
Any personal experience with the loose primer pockets?
Click to expand...

Of course, I've loosened up primer pockets plenty of times.


peaceatwar said:
Some deeper research will show that running any cartridge above the recommended pressure will destroy the brass.
Click to expand...

Thank you for this enlightening fact! Who'd of thunk it?

peaceatwar said:
Also don't forget to mention that 6 Competition Match and H1000 is for 28" and longer barrels.
Click to expand...

Not necessarily. Top velocity depends on long barrels for any powder, in any chambering - and H1000 is no different. I stand by my previous statement that 243ai and 6 Comp Match can achieve 3100+ fps with H1000. And, they can do it without F class length barrels. Of course, the longer barrels will allow them to go faster yet.
 
Not much trouble finding a 1/3 moa or less load in 243, atleast thats been my experience in 5 of them. I have a lw, sinarms( brux), criterion, and custom. All different reamers, or at least different smiths, could all be the exact. 105 hybrids seat at 2.265-2.275. Thats 20 thou off, bearing surface is still in nk, leaving room to chase rifling in standard ai mag. Some guys claim barrel life of 1200, i think they have never owned a 243. I have two that are at 2 k apiece, both will still throw down groups in the .2-.3s. I can't comment directly of 6 creed barrel life, but if both utilize similar barrels, same bullet wt, same fps, so on and so on. Not sure that there would be more then a couple hundred rds difference in life. I have a criterion remage barrel that has a wide accuracy window, basically 41.5-42.5 h4350 with 107 smk or 105 Berger results in .4 or smaller. Now some charges approached .18" and some exhibited single digit ES. Lots of sources for 243 brass not so for 6 creedmoor. Some guys are getting loose pockets in 1-2 firings trying to get 3100-3150. Junk brass or too high pressure u pick. I can get 3150 on win brass and get 10-12 reloads with 243.
 
Tikka currently being rebarreled in 6 creedmoor and have a stiller Spectre ordered for new 6 creedmoor build

Did all the same research of this thread several months back if you search this cartridge you can find great info
 
Another straight up 6mm Rem shooter here , gonna have a barrel spun up for my DTA soon . Does anybody have a ballistics comparison chart made up for these various 6mm's to compare to ? All info I found stated 6.5 & 6mm Rem were pretty close ballisticly
 
I'm on the 6SLR bandwagon too. Excellent velocities, easy to load, fun to shoot. I've been shooting mine for 2years now and I wouldn't change anything. I'd also look at the 6mm Competition Match. It's basically the same as the SLR though. Both are easy on barrels (relative), compaired with others. With H1000 you should be in that 4K range on barrel life.

xdeano
 
6brshooter said:
Rancid, specifics about ur rig. I am having a 243ai built on a tikka, wearing a 24" Krieger1-8. Plan to run 105 hybrids at 3100ish.
Click to expand...

Tikka T3 Lite, started life as a 308. Aaron Roberts at RPRifles did the work, re-barreled with a Kreiger 1:7.5, factory trigger, new bolt shroud and larger bolt handle, tossed the original stock in the trash and put it all in a Whiskey3 chassis. Still playing with various loads, but stuff it doesn't like - factory 243 - shoots under 1 MOA, tuned hand loads are running around 1/3MOA.

Will try to get a few pictures.

If you are considering, Aaron has the fixture for the T3 action and the reamer for 243AI in hand. I am exceedingly pleased with the outcome!
 
HodgdonExtreme said:
I personally think the 6SLR is ideal for PRS matches where 3150fps is generally the speed limit. SLR achieves 3150 with ease. The x47, XC and Creedmoor will also go 3150, but must be pushed harder. The x47 brass can obviously handle the pressure, but some Creedmoor shooters are complaining their brass is going to hell. Seems it is much happier at 3100.
Click to expand...

This was my choice, I have a reamer but am still practicing before putting it to steel.
 
I took a 28" 243Win barrel, cut .200 from the back and chambered in 6SLR.
243Win - 37.5gn Imr4064, 105 Noslers was 3020fps - with pressure signs on CCI primers.
Same load in 6SLR - 3200fps! and the primers don't look flattened anymore. I even switched to Federal primers and still no signs of pressure.
First time out - I shot High Master @ 600.

Seriously - it was like magic, the rifle went from WTF to OMG!
 
All of the above advice is perfect, No one's lying to you.

I agree if money is an issue and you want readily available materials, .243 is a great option. I know a x47lap guy who said his next build will be a .243.

I personally went 6XC, look at my thread, research David Tubb, and youll see why
 
I shot 6XC for two years before switching to the 6mm Competition Match. My vote is 6mm Comp Match in a repeater or straight 243 AI in a single shot. You'll get identical performance from the 6XC, 6x47 Lapua etc... but the advantage of the larger cases is that you can run H1000. This will take you barrel life from 2000 to 4000 which is a huge benefit. Both my 6XC barrels s**t the bed at just under 2k rounds.
Guys running their 6mm Comp Match's hard are still getting 3,500+ rounds, and babying with barrel setbacks will get you close to 5k rounds, no joke.
 
You must log in or register to reply here.

Similar threads

blacklab1
6mm Migraine
Replies
31
Views
2K
lash
lash
7mm-08 Freak
Witch 6MM cartridge?
Replies
22
Views
1K
cas6969
cas6969
B
SOLD 6BR complete package
Replies
3
Views
582
bross412
B
Benhonda1
6mm ARC questions
Replies
16
Views
1K
Bluedog82
Bluedog82
Tikka595II
Firearms couple of rifles and barreled actions
Replies
17
Views
3K
Tikka595II
Tikka595II
Top Bottom
Back