buffer weight issue

[LRRPF52]

The first build I did was with an 18" Faxon gunner barrel and a gas system described as "mid".
I know that one had a standard mil spec buffer.
The current build has an 18 " BA fluted barrel with a rifle length gas system, finding out they are all unique.
Both were built on a carebine length buffer system.
I have a 223 wylde upper I am planning on running with this lower.
So I think I will keep the light buffer for that combo and purchase a heavier one for the 6.5.
H or H2, any suggestions would be appreciated
Thanks. Greg

It all depends on port diameter and the load you're shooting, as well as the condition of the BCG, chamber, and recoil spring.

The Grendel was engineered to be a drop-in solution for existing AR15 lowers, but many barrels in the after-market have used different gas port diameters.

The Grendel gas ports actually seem to correspond with 5.56 gas port diameters at the different locations.

Buffer weights are primarily for countering carrier bounce on automatic-capable rifles, with a secondary function as rate reducers.

The buffer style we currently use was actually meant as a rate reducer when the Army switched to ball powders in the AR15 in the early 1960s, even though the rifle was engineered around tiny extruded powders like 8208M.

Depending on what load you shoot, your port pressure will be quite different, so it really helps to nail down what load range you primarily want to feed the system.

The extremes of that with 6.5 Grendel are 85gr on the low end for hand loads, followed by 90gr TNT factory ammo from Federal, with 130gr on the high end of factory ammo, and even heavier for hand loads.

Some ways to deal with this are adjustable gas. The easiest adjustable gas system I've seen so far is the Bootleg Adjustable Gas Carrier, which I have.