6mm vs 243
- Thread starter pyscodog
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Rustydust
Active member
I have been reloading and reading reloading books for well over 40 years and I do not remember ever seeing anything where a standard .243 Winchester outperforms a 6mm Remington. They are very close to each other but the given the same pressures the larger capacity case of the 6mm is going to outspeed the .243 Win. I will admit that the difference is small and not ever going to noticeable by anything you ever shoot with it but there IS a difference. 100 FPS or so. Negligible.
I own or have owned .243 and .243 AI rifles. Great cartridges. There is a reason that the now 60 year old round is still selling like it is.
I own or have owned .243 and .243 AI rifles. Great cartridges. There is a reason that the now 60 year old round is still selling like it is.
6mm Rem is better suited for a long action, second you have to scrounge for brass in this caliber.
243 will not outperform the 6 Rem using less powder, as the 6 Rem will shoot any bullet accurately about 100 fps faster or more.
You can make 6 Rem cases from 7x57 or 257 Roberts brass easily, but you will have to neck turn the brass.
243 AI is a fantastic cartridge given match dimensions on the chamber with a freebore that will match your intended bullet, ie. don't put a freebore to match a 105g berger then want to shoot a 70g Nosler.
The 6Rem AI is a power wagon and a half, just don't screw up the custom job by putting it on a short action.
While or if you are considering customs, consider the 6 XC and the 6 SLR that are 95% of the 243 Win or equal the 243 Win with less powder, longer necks that give 1000 rounds more barrel life.
Having said that, the 243 Win loaded with 100g bullets and R#26 will be getting 3300 fps perhaps a little more depending on the barrel.
243 will not outperform the 6 Rem using less powder, as the 6 Rem will shoot any bullet accurately about 100 fps faster or more.
You can make 6 Rem cases from 7x57 or 257 Roberts brass easily, but you will have to neck turn the brass.
243 AI is a fantastic cartridge given match dimensions on the chamber with a freebore that will match your intended bullet, ie. don't put a freebore to match a 105g berger then want to shoot a 70g Nosler.
The 6Rem AI is a power wagon and a half, just don't screw up the custom job by putting it on a short action.
While or if you are considering customs, consider the 6 XC and the 6 SLR that are 95% of the 243 Win or equal the 243 Win with less powder, longer necks that give 1000 rounds more barrel life.
Having said that, the 243 Win loaded with 100g bullets and R#26 will be getting 3300 fps perhaps a little more depending on the barrel.
Only reference was my Hornady reloading book. It was showing a bit more velocity using less powder. I really figured the 6 would out perform the 243 but thought I might be missing the real truth from the book. Thats why I like to ask the real world guys the questions. Just reading and got curious.
Theshedhunter
Active member
My shooting and loading mentor (the one with a cabin FULL of sweet vintage firearms
)has several 6mm Rems that we shoot on occasion. He's killed tons of speedgoats, deer, and elk with them. I believe it is his favorite non-magnum cartridge, (he has a real soft spot for the large Weatherby's). Here is a pic I snapped for comparison to my .243. Long neck, more case cap. Whats not to like?
Rustydust
Active member
Originally Posted By: tripod3The .243 has outperformed the 6mm in sales.
While that is true, there is a reason for it. Had both cartridges had identical rifles and ammo made for them to start off with I doubt that the .243 would be as popular today. Winchester sold the .243 as deer cartridge that could be used for varmints. Remington touted the 6mm (then the .244 Remington) purely as a varmint round and did not even offer ammo suitable for big game. Consequently sales of the .243 took off while the .244 sales were flatter then week old beer. The rest, as they say, is history.
While that is true, there is a reason for it. Had both cartridges had identical rifles and ammo made for them to start off with I doubt that the .243 would be as popular today. Winchester sold the .243 as deer cartridge that could be used for varmints. Remington touted the 6mm (then the .244 Remington) purely as a varmint round and did not even offer ammo suitable for big game. Consequently sales of the .243 took off while the .244 sales were flatter then week old beer. The rest, as they say, is history.
tripod3
New member
Originally Posted By: RustydustOriginally Posted By: tripod3The .243 has outperformed the 6mm in sales.
While that is true, there is a reason for it. Had both cartridges had identical rifles and ammo made for them to start off with I doubt that the .243 would be as popular today. Winchester sold the .243 as deer cartridge that could be used for varmints. Remington touted the 6mm (then the .244 Remington) purely as a varmint round and did not even offer ammo suitable for big game. Consequently sales of the .243 took off while the .244 sales were flatter then week old beer. The rest, as they say, is history.
Yes I've read about the marketing popularity before my time.
I read the twist rates were different on the .244 and with flat sales Rem discontinued the cartridge, they renamed it 6mm Rem later on reintroduction.
While that is true, there is a reason for it. Had both cartridges had identical rifles and ammo made for them to start off with I doubt that the .243 would be as popular today. Winchester sold the .243 as deer cartridge that could be used for varmints. Remington touted the 6mm (then the .244 Remington) purely as a varmint round and did not even offer ammo suitable for big game. Consequently sales of the .243 took off while the .244 sales were flatter then week old beer. The rest, as they say, is history.
Yes I've read about the marketing popularity before my time.
I read the twist rates were different on the .244 and with flat sales Rem discontinued the cartridge, they renamed it 6mm Rem later on reintroduction.
Originally Posted By: JLJ223I have both and for all intentional purposes there isn't any big difference, if I were buying one today I would go with the 243 simply for the availability of brass/ammo.
There is one other thing that Remington did that sabotaged the 6mm and that was the early twist rate offered. Those early rifles didn't seem to bench shoot like the cartridge should have. My first centerfire was a Sako .243 that would shoot half inch groups with several factory loads with the occasional ragged one hole.
I've had bad experience with 2 6mm's, but have known guys with customs that they liked a lot. I had heard that at some point it was offered with the twist it should have had from the start but the fate was already sealed compared to the .243. I also had a Sako heavy barrel Varmint .243 that was a 500 yard squirrel killing machine. Both Sakos loved light bullets and Federal match bullets as well. The .243 has a considerable amount of excellent performance factory cartridges offered.
There is one other thing that Remington did that sabotaged the 6mm and that was the early twist rate offered. Those early rifles didn't seem to bench shoot like the cartridge should have. My first centerfire was a Sako .243 that would shoot half inch groups with several factory loads with the occasional ragged one hole.
I've had bad experience with 2 6mm's, but have known guys with customs that they liked a lot. I had heard that at some point it was offered with the twist it should have had from the start but the fate was already sealed compared to the .243. I also had a Sako heavy barrel Varmint .243 that was a 500 yard squirrel killing machine. Both Sakos loved light bullets and Federal match bullets as well. The .243 has a considerable amount of excellent performance factory cartridges offered.
Originally Posted By: tripod3The .243 has outperformed the 6mm in sales.
And Ford outsells Ferrari but which would you rather have??
The real problem which may be no problem what so ever for you is the short neck on the 243 case. In my old Sako Forester I had to seat the bullets out a way in order to get the accuracy I desired. Problem is I was in a big hurry to re-chamber a round one time and the projectile turned in the camber causing me to lose a coyote that had jumped on me and tried to bite my face.
The 6mm is easier to reload and slightly outperforms the 243. It would be my first choice. Converting to a 6mm Ackley Improved would even be better.
And Ford outsells Ferrari but which would you rather have??
The real problem which may be no problem what so ever for you is the short neck on the 243 case. In my old Sako Forester I had to seat the bullets out a way in order to get the accuracy I desired. Problem is I was in a big hurry to re-chamber a round one time and the projectile turned in the camber causing me to lose a coyote that had jumped on me and tried to bite my face.
The 6mm is easier to reload and slightly outperforms the 243. It would be my first choice. Converting to a 6mm Ackley Improved would even be better.
Originally Posted By: tripod3Originally Posted By: RustydustOriginally Posted By: tripod3The .243 has outperformed the 6mm in sales.
While that is true, there is a reason for it. Had both cartridges had identical rifles and ammo made for them to start off with I doubt that the .243 would be as popular today. Winchester sold the .243 as deer cartridge that could be used for varmints. Remington touted the 6mm (then the .244 Remington) purely as a varmint round and did not even offer ammo suitable for big game. Consequently sales of the .243 took off while the .244 sales were flatter then week old beer. The rest, as they say, is history.
Yes I've read about the marketing popularity before my time.
I read the twist rates were different on the .244 and with flat sales Rem discontinued the cartridge, they renamed it 6mm Rem later on reintroduction.
Ooops, sorry, I hadn't read all the posts or I would have acknowledged your catching that. My bad.
While that is true, there is a reason for it. Had both cartridges had identical rifles and ammo made for them to start off with I doubt that the .243 would be as popular today. Winchester sold the .243 as deer cartridge that could be used for varmints. Remington touted the 6mm (then the .244 Remington) purely as a varmint round and did not even offer ammo suitable for big game. Consequently sales of the .243 took off while the .244 sales were flatter then week old beer. The rest, as they say, is history.
Yes I've read about the marketing popularity before my time.
I read the twist rates were different on the .244 and with flat sales Rem discontinued the cartridge, they renamed it 6mm Rem later on reintroduction.
Ooops, sorry, I hadn't read all the posts or I would have acknowledged your catching that. My bad.
sandy hicks
New member
I will take the Ford. That ferrari may be fast, but speed wont get me past the first mud hole after i stop and close the gate. No place to hual feed, deer, and other stuff that got shot. Would have the money left over for a 6mm and a 243 and buy all of the stuff to feed them.
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Originally Posted By: pk1Originally Posted By: tripod3The .243 has outperformed the 6mm in sales.
And Ford outsells Ferrari but which would you rather have??
The real problem which may be no problem what so ever for you is the short neck on the 243 case. In my old Sako Forester I had to seat the bullets out a way in order to get the accuracy I desired. Problem is I was in a big hurry to re-chamber a round one time and the projectile turned in the camber causing me to lose a coyote that had jumped on me and tried to bite my face.
The 6mm is easier to reload and slightly outperforms the 243. It would be my first choice. Converting to a 6mm Ackley Improved would even be better.
I had a .243 WSSM Model 70 that was like the hammer of Thor, 5 inch drop at 500 yards, bad hind quarter hits and they were still DRT, 55gr at 4100fps. I've been wanting an AR .243WSSM that is made by Newtown Firearms in Placerville, they will guarantee that it will shoot 6 inch groups at 600 yards and prove it to you. That would be wicked for multiples.
And Ford outsells Ferrari but which would you rather have??
The real problem which may be no problem what so ever for you is the short neck on the 243 case. In my old Sako Forester I had to seat the bullets out a way in order to get the accuracy I desired. Problem is I was in a big hurry to re-chamber a round one time and the projectile turned in the camber causing me to lose a coyote that had jumped on me and tried to bite my face.
The 6mm is easier to reload and slightly outperforms the 243. It would be my first choice. Converting to a 6mm Ackley Improved would even be better.
I had a .243 WSSM Model 70 that was like the hammer of Thor, 5 inch drop at 500 yards, bad hind quarter hits and they were still DRT, 55gr at 4100fps. I've been wanting an AR .243WSSM that is made by Newtown Firearms in Placerville, they will guarantee that it will shoot 6 inch groups at 600 yards and prove it to you. That would be wicked for multiples.
xphunter
Well-known member
Short or long action?
Barrel length?
Max bullet weight and uses?
Originally Posted By: pyscodogWhat will a 6mm do that a 243 won't? Looking through my Hornady book, the 243 will out perform the 6mm using less powder. Am I missing something or ready my book wrong? Help me here.
Barrel length?
Max bullet weight and uses?
Originally Posted By: pyscodogWhat will a 6mm do that a 243 won't? Looking through my Hornady book, the 243 will out perform the 6mm using less powder. Am I missing something or ready my book wrong? Help me here.
Originally Posted By: xphunterShort or long action?
Barrel length?
Max bullet weight and uses?
Originally Posted By: pyscodogWhat will a 6mm do that a 243 won't? Looking through my Hornady book, the 243 will out perform the 6mm using less powder. Am I missing something or ready my book wrong? Help me here.
Not anything in particular xphunter. A friend called me about a rifle and was telling me he bought a 6mm remington. After the call, I got my Hornady book out and was comparing the 6mm to the 243. It started with a 58 grain bullet and I just compared it to the other and read load data up to about the 75 grain pills. The 243 had the same velocities using less powder. Thats why I posted 6mm vs 243.Just reading and comparing book data.
Barrel length?
Max bullet weight and uses?
Originally Posted By: pyscodogWhat will a 6mm do that a 243 won't? Looking through my Hornady book, the 243 will out perform the 6mm using less powder. Am I missing something or ready my book wrong? Help me here.
Not anything in particular xphunter. A friend called me about a rifle and was telling me he bought a 6mm remington. After the call, I got my Hornady book out and was comparing the 6mm to the 243. It started with a 58 grain bullet and I just compared it to the other and read load data up to about the 75 grain pills. The 243 had the same velocities using less powder. Thats why I posted 6mm vs 243.Just reading and comparing book data.