Buffer tube and spring for 20" 6.5 Grendel upper?

[Pistoler0]

What buffer tube length and spring weight is appropriate for a 6.5 Grendel upper with a 20" barrel?

Gas tube is rifle length with diameter .750 and adjustable gas block.

[FrankenMauser]

Whatever you want to run. Just make sure the spring matches the buffer tube.
Buffer choice depends on how it runs. I start with standard and let the parts wear in before considering a change.

[stagpanther]

Depends what you're making--pistol, fixed rifle stock or adjustable carbine.

[Pistoler0]

Originally Posted by stagpanther

Depends what you're making--pistol, fixed rifle stock or adjustable carbine.

Adjustable carbine (even if barrel is 20")

[Shadow9mm]

Personally i prefer carbine length buffer system. Its more tunable than rifle length. Multiple buffer weights and spring strengths. Especially with an adjustable gas block id expect no issues. Id go carbine lenght with an h buffer and standard spring. Set it up and adjust your gas block. If your somehow still ejecting forward , instead of the 3 to 4 oclock position id add a springco extra power spring.

Im currently running a 6mm arc, kind of a sister cartridge. 20in barrel, rifle length gas, adjustable gas block, carbine length buffer tube, h buffer and a jp +5% spring. It was ejecting at 3:30 even before i tuned the gas. The springco blue +15% was too strong. Going to try a carbine buffer next outing and see what it does.

[stagpanther]

Buffer choice depends on how it runs. I start with standard and let the parts wear in before considering a change.

I agree with this--establish that you have basic functionality with a range of different power-level cartridges before embarking on musical-components.

[Pistoler0]

Originally Posted by Shadow9mm

Personally i prefer carbine length buffer system. Its more tunable than rifle length. Multiple buffer weights and spring strengths. Especially with an adjustable gas block id expect no issues. Id go carbine lenght with an h buffer and standard spring. Set it up and adjust your gas block. If your somehow still ejecting forward , instead of the 3 to 4 oclock position id add a springco extra power spring.

Im currently running a 6mm arc, kind of a sister cartridge. 20in barrel, rifle length gas, adjustable gas block, carbine length buffer tube, h buffer and a jp +5% spring. It was ejecting at 3:30 even before i tuned the gas. The springco blue +15% was too strong. Going to try a carbine buffer next outing and see what it does.

Thank you for the detailed advice Shadow9 and StagPanther,

I am ordering an Aero Precission carbine length and buffer right after I post this.

[Shadow9mm]

Originally Posted by Pistoler0

Thank you for the detailed advice Shadow9.

I am ordering an Aero Precission carbine lenght H buffer right after I post this.

Happy to help and happy building! Keep us updated on how it goes!