6MM Remington?

[kc]

Is the cartridge designed for a long action, I wonder how it would be necked out for 6,5MM?

[EddieHarren]

It was and, still is offered in the SA. It does very well in the LA also. Like it's big brother, the 257 Roberts, the longer action allows the bullets to be seated out, closer to the lands.
As for necking up to .264, there are so many good cartridges available, in this bore size, that the extra cost of custom dies, reamers etc. would not seem to make sense.

[johnnyk]

kc,
Like Eddie said, it is offered in SA and LA. It is based off the .257 Roberts which was derived from the 7X57 Mauser case. It (7X57) originally started life in a long action. I wouldn't think there would be any benefit to go SA if you were thinking of long for caliber, ballistically effeciant bullets for long range.
All three of these cartridges have enjoyed good success. I say "good" because like alot of other "good" cartridges they have been somewhat left behind. The shooting industry folks have introduced and updated as they saw fit. The 7mm-08 does everything the 7X57 does, the .25-06 (25WSSM) out classes the .257 Roberts. The .243 does not out class the 6mm ballistically, but Winchester got a foot hold on the market by introducing the .243 with the right barrel twist.
It (6mm) would probably make a good cartridge necked up to 6.5. It may have already been done. .264" is right in between .257" and .284". The case is slightly longer than the 6.5X55 Sede, which is a great cartridge, so with that you could probably get a little bit better ballistics from it.
You already have the .260Rem, 6.5-06 (and AI vers.), the 6.5X284, 6.5BR, 6.5RemMag, .264WinMag. I think there's also other wildcats out there (6.5 STW) that could provide the same or better level of performance.
Or if you just dead set on a 6mm necked up to 6.5, go for it. Either route you choose, have fun along the way. Happy shooting! JohnnyK.

[kc]

Just thinking...I still plan to build (have) a .260 in a Remington action. My gunsmith who built some fantastic one holers @100 yards will be doing the work on this one..He already knows it will be for reaching out and touching yotes and deer. What they did to an old springfield made me proud.(Williams Gun Sight).

[wildcat]

Go with the Long Action.

W.