I have a Remington 700 action made into a 6.5-284
What barrel length should I use and what twist rate? I plan on shooting 120 to 140 gr bullets.
I am having the action trued and the lugs lapped.

26inches or longer with a 1 in 8 twist. Yu ould go., but if are planning on using only weights of 120 or above the 8 is the best way to go.

BlueMule,

My Rem M700 6.5-'06 has a Shilen 23.6" (600 mm) barrel with a 9" twist. This combination works fine for hunting Western animals with bullets up to about 160 grains, and it shoots the 120 to 140 grain bullets very accurately.

If you have a particular bullet in mind that you want to shoot for a particular application, that will drive your choice.

If you are a target shooter I would expect a longer barrel to get velocity up, and a slower twist following the target "slowest twist that does the job" theory.

If you want to shoot very heavy bullets for hunting, then you need more twist. The European standard for the 6.5X55 is 7.87" (200 mm) IIRC.

jim dodd