midland man
Member
so guy I see no one has talked much about the difference between these two catridges so could someone tell what they are?? thanks! 
6mm creedmore vs 243 winchester whats the difference??
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Riomouse911
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For all practical purposes? A faster standard twist rate and a shorter case with a steeper shoulder on the CM to handle slightly longer-heavier bullets. And the “heavier” is between 5 and 20 grains, so it ain’t like we’re talking elephant medicine.
Stay safe.
Stay safe.
mustanger98
Member
I'd say the difference for some of us is number of deer harvested with the 6mmCM isn't nearly the same as we've got with the .243Win.
Demi-human
maybe likes firearms a little bit…
One is "The New Hotness", the other is "old and busted".
In the before times, hunters used these short thin bullets for varmint or meat harvest.
Now, in the time of all that is, humans use these small bullets to shoot long distances at relatively small objects, which needs longer sleeker bullets that require a tighter twist.
One is hard pressed to find high B.C. bullets in a varmint cartridge loading from the factory, as well as a short, less to ricochet bullets in a target Creedmoor case.
But the lines are becoming blurred...
In the before times, hunters used these short thin bullets for varmint or meat harvest.
Now, in the time of all that is, humans use these small bullets to shoot long distances at relatively small objects, which needs longer sleeker bullets that require a tighter twist.
One is hard pressed to find high B.C. bullets in a varmint cartridge loading from the factory, as well as a short, less to ricochet bullets in a target Creedmoor case.
But the lines are becoming blurred...
Or just say you can stick on in an AR.....this is the only reason one exists.
gotboostvr
Member
Except they BOTH work in an AR10.
dieselchief
Member
I had a ruger predator in 243, needed a couple of bucks sold it. replaced it with the 6 creedmore. both just as accurate. 243 is noisy enough, the creedmore is even more so. just saying.
243winxb
Member
The 6 creedmoor will produce higher velocity over the 243 win using same bullet/powder, maximums. H4350 & IMR 4064. 80 & 100gr bullets. Compared at Hodgdons.
The Creedmoor working PSI is 2000 higher the 243.
Is the 6 creedmoor better then the 243 win? Yes. Faster 6 Creedmoor twist, for longer, heavier bullets.
Brass 6 creedmoor - 38 cents each.
Brass 243- 35 cents each. Both Hornady bulk.
Edit/add- for deer, just buy a 308 Win. Its even good for plains game hunting in South Africa to 250 yards. Lady from club just back. Did well with 308 & 165 gr Noslers.
The Creedmoor working PSI is 2000 higher the 243.
Is the 6 creedmoor better then the 243 win? Yes.
Faster 6 Creedmoor twist, for longer, heavier bullets.Brass 6 creedmoor - 38 cents each.
Brass 243- 35 cents each. Both Hornady bulk.
Edit/add- for deer, just buy a 308 Win. Its even good for plains game hunting in South Africa to 250 yards. Lady from club just back. Did well with 308 & 165 gr Noslers.
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Varminterror
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This isn’t true in the least. LFAR’s have been available in .243win long before the 6 Creed was even a twinkle in the eye.
Varminterror
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I started shooting a 243win around 20yrs ago as a coyote rifle, eventually deer as well. I started then shooting another 243win, much heavier, for long range benchrest - which I then quickly replaced with a .243AI. I’ve had several coyote, prairie dog, deer, and target rifles, including LFAR’s, and specialty pistols in bolt action and break action since then. Fast twist, standard twist, long barrels, short barrels - the 243win/243AI has been one of my favorite cartridges for many years.
The 243win and 243AI never really were ideal for me when shooting long range benchrest, but with a fast twist barrel and a single shot, long action, it still wasn’t the worst choice I could have made.
So then ~3yrs ago, I started into Precision Rifle Competition. Watching the sport for a few years before that, I immediately realized the advantage of a fast 6mm cartridge over the then-current-State 6.5’s. I was running a few 6.5 creeds through test flights for other uses, and really didn’t see the applicability for the round within the format of the game. Great for a beginner who needed a long barrel life to get started at lower cost, but certainly not a competitive advantage from where I sat. I had planned to start out with a Ruger Precision Rifle in 243win, so I bought a Gen 2, but shortly thereafter, Ruger announced the 6 creed version, and Seekins announced their Havak line of rifles - also available in 6 creed. Also at that time, a student had also built a 6.5 Grendel AR in one of my classes which was fairly well suited for precision rifle competition. So I shot a few matches with the 243win RPR and that Grendel, and a 6.5 creed Savage 12 I had restocked as a BA Stealth clone, until I finally found a Seekins Havak in 6 creed on the shelf.
Both go bang, both shoot flat, both shoot small. Both can be loaded to the same pressure (same bore, same bolt face, same rifles), and the .243win will run faster with the same bullet as the 6 creed - but the ~100-150fps difference is really irrelevant. The 6 creed is more efficient, meaning a touch less powder per fps. I’ve found broader velocity nodes, closer together in the Creedmoor case, meaning I have a more forgiving round with more loading options. Case stretch is less in the 6 creed, so even though I do trim every time, I don’t spend as much time, and I don’t have to worry as much about case head separation with repeated firing. The 243win isn’t finicky, but it’s certainly moreso than the 6 creed for load development - just as the 6 creed is moreso than 6 Dasher. I use a bit less powder in 6 creed, meaning a bit less ammo cost and a bit less recoil - both small, but real advantages. Barrel life is considerably better in 6 creed - I’ve taken 2 barrels to the grave in 6 creed and a dozen or so in 243win, the Creed will run about 30-50% longer barrel life.
Would I hit as many targets in competition with a 243win as I do with a 6 creed? Yeah, probably, although I’d struggle with logistics and likely miss some matches as I’d be replacing barrels mid-season instead of stretching out to finish a whole season on one tube. Do I unilaterally recommend the 6 creed over the 243win for a would-be precision rifle competitor? Absolutely.
Plain and simple - precision competitors asked for the creedmoor case. There WERE .243win and .243AI rifles which qualified for the PRS finale every year before the 6 creed came out. Now, it’s just a fond memory. If it were a coin flip, we’d see a balanced diet of both - like we do with 6 Dasher, BR, BRA, BRX, or the 6 creed and 6x47L. But the 243win was pushed out because it doesn’t carry the sum of advantages which come with these other cases.
None of that means the 243win isn’t a great cartridge, nor does it mean it’s not a great deer killing cartridge. I’ve said many times in the last 10yrs: the 243win is likely the most efficient whitetail killing cartridge - without concession - on the market. This remains to be true, the 6creed stands right beside it for that title, but in hunting fields, the two are interchangeable. But on competition firing lines, where optimal performance is critical, the 6 creed sits at the head of the table, while the 243win isn’t even invited to the party.
The 243win and 243AI never really were ideal for me when shooting long range benchrest, but with a fast twist barrel and a single shot, long action, it still wasn’t the worst choice I could have made.
So then ~3yrs ago, I started into Precision Rifle Competition. Watching the sport for a few years before that, I immediately realized the advantage of a fast 6mm cartridge over the then-current-State 6.5’s. I was running a few 6.5 creeds through test flights for other uses, and really didn’t see the applicability for the round within the format of the game. Great for a beginner who needed a long barrel life to get started at lower cost, but certainly not a competitive advantage from where I sat. I had planned to start out with a Ruger Precision Rifle in 243win, so I bought a Gen 2, but shortly thereafter, Ruger announced the 6 creed version, and Seekins announced their Havak line of rifles - also available in 6 creed. Also at that time, a student had also built a 6.5 Grendel AR in one of my classes which was fairly well suited for precision rifle competition. So I shot a few matches with the 243win RPR and that Grendel, and a 6.5 creed Savage 12 I had restocked as a BA Stealth clone, until I finally found a Seekins Havak in 6 creed on the shelf.
Both go bang, both shoot flat, both shoot small. Both can be loaded to the same pressure (same bore, same bolt face, same rifles), and the .243win will run faster with the same bullet as the 6 creed - but the ~100-150fps difference is really irrelevant. The 6 creed is more efficient, meaning a touch less powder per fps. I’ve found broader velocity nodes, closer together in the Creedmoor case, meaning I have a more forgiving round with more loading options. Case stretch is less in the 6 creed, so even though I do trim every time, I don’t spend as much time, and I don’t have to worry as much about case head separation with repeated firing. The 243win isn’t finicky, but it’s certainly moreso than the 6 creed for load development - just as the 6 creed is moreso than 6 Dasher. I use a bit less powder in 6 creed, meaning a bit less ammo cost and a bit less recoil - both small, but real advantages. Barrel life is considerably better in 6 creed - I’ve taken 2 barrels to the grave in 6 creed and a dozen or so in 243win, the Creed will run about 30-50% longer barrel life.
Would I hit as many targets in competition with a 243win as I do with a 6 creed? Yeah, probably, although I’d struggle with logistics and likely miss some matches as I’d be replacing barrels mid-season instead of stretching out to finish a whole season on one tube. Do I unilaterally recommend the 6 creed over the 243win for a would-be precision rifle competitor? Absolutely.
Plain and simple - precision competitors asked for the creedmoor case. There WERE .243win and .243AI rifles which qualified for the PRS finale every year before the 6 creed came out. Now, it’s just a fond memory. If it were a coin flip, we’d see a balanced diet of both - like we do with 6 Dasher, BR, BRA, BRX, or the 6 creed and 6x47L. But the 243win was pushed out because it doesn’t carry the sum of advantages which come with these other cases.
None of that means the 243win isn’t a great cartridge, nor does it mean it’s not a great deer killing cartridge. I’ve said many times in the last 10yrs: the 243win is likely the most efficient whitetail killing cartridge - without concession - on the market. This remains to be true, the 6creed stands right beside it for that title, but in hunting fields, the two are interchangeable. But on competition firing lines, where optimal performance is critical, the 6 creed sits at the head of the table, while the 243win isn’t even invited to the party.
Legionnaire
Contributing Member
^^ Excellent summary. Were I starting out, I would no doubt purchase a 6 Creed for targets and a 6.5 Creed for most of my hunting needs; definitely what I would recommend to a new shooter. As it is, I'll stick with my .243 Win, .243 Ackley, .260 Rem, and .260 Ackley. When those barrels are shot out (it will be a while, as I'm not a competitor), I may rebarrel in a Creedmoor.
Varminterror
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It’s been about 15 years since I have bought 243win ammo from a shelf.
6 creedmoor ammo has been on the shelf at most of my local stores for the last 2 years as well. Even if I’ve never bought a single box of it - it’s there if I had to (also won’t fit my rifle, since I’m throated for the 105 Hybrid). My local shops which get my business are also happy to include my personal items on their orders, if and when I need them to do so, such I can access any product in their supply chain. However, doing so rarely makes sense in the last decade or so, since Midway and Brownells will deliver it to my door also, often at a lower price, so I never worry much about what a high-overhead local business stocks on their shelf unless they’re willing to work with me to have what I need at a fair price, when I need it.
mcb
Member
I have not shot much 243 Win so can't say much about it. I have shot a fair bit more 6mm CM.
This is a 200 yard, 5-shot group I shot and it measures .80-inch or .38 MOA. This was a factory Remington 700 shooting Barnes factory ammunition (not hand-loads). After I worked up my dope I was ringing 2MOA steel targets at 1000 yards with relative ease.
This is a 200 yard, 5-shot group I shot and it measures .80-inch or .38 MOA. This was a factory Remington 700 shooting Barnes factory ammunition (not hand-loads). After I worked up my dope I was ringing 2MOA steel targets at 1000 yards with relative ease.
Varminterror
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There has/have been single shot 50bmg uppers for AR’s for a long time. Can’t and won’t say they’re pretty or practical, but they’re there.
Varminterror
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The above statement is true for a hundred or so cartridges. Why should the OP or anyone else pick the 308win because you picked it out of those hundred cartridges?
Forgive me for not drinking the koolaid, but there’s never been a time a .308win impressed me for any purpose.
The 6mm uses a small rifle primer. The .243 uses a large.
This might not be as significant as the other valid differences already pointed out. I just want to add it because it does make a difference. In the most practical terms for me, lead-free small rifle primers are available whereas lead-free large rifle primers are not available.
Federal is now selling their Copper Power-Shok loaded ammunition with "Catalyst" lead-free primers, including .243. So I believe Federal is producing lead-free large rifle primers unless they're making .243 cases with small rifle primer pockets. I inquired with Federal about buying Catalyst primers as a component. They responded that they do not and that there is currently no discussion on doing so in the future.
In the meantime, Fiocchi sells lead-free small rifle magnum primers (as well as small pistol). These are not the Russian DDNP primers from the past, but they are bismuth-oxide/aluminum primers -- the same technology that Federal has announced will be for their entire product line within a few years. These are the only primers on the market as a component that are safe for your health and the health of your children, and they fit 6mm Creedmoor cases, but they do not fit .243 Winchester cases.
This might not be as significant as the other valid differences already pointed out. I just want to add it because it does make a difference. In the most practical terms for me, lead-free small rifle primers are available whereas lead-free large rifle primers are not available.
Federal is now selling their Copper Power-Shok loaded ammunition with "Catalyst" lead-free primers, including .243. So I believe Federal is producing lead-free large rifle primers unless they're making .243 cases with small rifle primer pockets. I inquired with Federal about buying Catalyst primers as a component. They responded that they do not and that there is currently no discussion on doing so in the future.
In the meantime, Fiocchi sells lead-free small rifle magnum primers (as well as small pistol). These are not the Russian DDNP primers from the past, but they are bismuth-oxide/aluminum primers -- the same technology that Federal has announced will be for their entire product line within a few years. These are the only primers on the market as a component that are safe for your health and the health of your children, and they fit 6mm Creedmoor cases, but they do not fit .243 Winchester cases.
Varminterror
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Large and small primer brass is readily available for 6 creedmoor. Some companies even make both. My Hornady 6 creed brass is large, my Lapua is small.
Similarly, if you want small primed 243win brass, you buy Lapua Palma brass, and neck it down. All of my competition 243win and 243AI brass for ~20yrs has been Lapua Palma, small primer.
243winxb
Member
Nato likes it. But its old and boring from the 1950s. Then came the 308 Win. Then some fool necked it down to 6mm.
https://www.americanrifleman.org/ar...iping-ammunition-from-vietnam-to-afghanistan/Then theres the 300 win mag if more range is needed.
Varminterror
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Luckily for me, I don’t have the same need from my firearms as NATO, nor their logistical burdens, so their opinion matters little to me.
gotboostvr
Member
50BMG uppers have been a thing for a good long while now.
https://www.mccutchenfirearms.com/50BMG-Upper-Receivers-s/106.htm
Heck, someone even made(makes?) A crossbow upper.
Same difference between 243 and 6 CM as between 260 and 6.5 CM. Both the 260 and 243 were designed around hunting bullets. Even in the same weight hunting bullets are shorter and work with faster twists and still fit in the magazines. The 260 was designed around 120 gr hunting bullets. and the 243 around 95-100 gr hunting bullets. Target shooters wanted to shoot longer, heavier bullets (117gr in 6mm and as much as 156 gr in 6.5) with high BC's for long range target shooting. They were having to modify factory 243 and 260 rifles with new barrels and modified magazines designed to shoot much longer bullets than possible in factory 260 and 243 rifles. As well as hand loading 243 and 260 to non standard dimensions that wouldn't work in standard rifles.
If you limit yourself to lighter weight hunting bullets there is no difference. If you want to shoot longer, heavier high BC bullets the 6mm CM offers a significant advantage in off the shelf rifles and ammo.
If you limit yourself to lighter weight hunting bullets there is no difference. If you want to shoot longer, heavier high BC bullets the 6mm CM offers a significant advantage in off the shelf rifles and ammo.
Old Stumpy
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The main difference between the 6.5 Creedmoor and the .243 seems to be 20 grains of bullet weight in favor of the 6.5 at around 3000 FPS.
The 6.5 Creedmoor, introduced in 2007, is a very good cartridge and certainly it gives the .243 and a number of other cartridges a run for their money.
But if so, why didn't the 6.5 Swedish before it? It was generally well known before 2007, and has about identical ballistics, so why didn't U.S. makers just add this cartridge to their rifle line-up?
Certainly, in a modern rifle with a precision barrel, it would have given the .243 and those other cartridges a run for their money a lot sooner, if there was a demand.
The 6.5 Creedmoor, introduced in 2007, is a very good cartridge and certainly it gives the .243 and a number of other cartridges a run for their money.
But if so, why didn't the 6.5 Swedish before it? It was generally well known before 2007, and has about identical ballistics, so why didn't U.S. makers just add this cartridge to their rifle line-up?
Certainly, in a modern rifle with a precision barrel, it would have given the .243 and those other cartridges a run for their money a lot sooner, if there was a demand.
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