talk with a barrel maker as for a best gas port size AND location is very important! +2 or 3 isn't necessary if port is sized proper! on some of the smaller bores they go +3 (might be a good suggestion). go with a 1/2 to a 1 full twist faster than minimum in an ar as velocities can be slower than with ba's. also, make sure you get a mag that works with the lower (reference: aero lowers don't work with acs mags due to bolt issues). the acs mags are lower cost and give a 2.860-2.870" cartridge length. on the higher end larue gives the same lengths, but cost is near $100/per. from custom makers i bought from do the gas port for adjustables in the .095-1.00" range. you can get a port reamed to what you want? i have a 243win rifle length gas that overgassed along with several other 6.5creeds. the only 2 creeds that run w/o adjustable blocks came from aero precision.
