Picked up an Aero complete lower from LGS. Changed out buffer tube to rifle length buffer with spring and Aero rifle buffer and added the butt I am used to on other ARs. Added ELF trigger set at #3. Added an Aero M5 upper with 20" barrel. Waiting for BCG, extended charging handle and adjustable gas block. For those that need to know, the gas port is .093 and the tube extends to the center of the cutout. Learning day by day with the M5. Added a MK 4 16x fixed. Was going to use on of my Night Force ATACRs but the bell is just to big on this handguard without raising rings so I ordered a different 15" Mlock handguard from Aero, less costly than NF rings, that does not have the rail full length. That should do the trick. Whatta Hobby!