The gun is a post-ban Bushmaster XM15-E2S with a JP trigger and thousands of rounds down the 16.5" 1:9 H-Bar barrel. The bore gets cleaned every trip to the range. The action gets cleaned every so often.
At 100 yards The American Eagle ball ammo is good but not great:
Yesterday I tried 7 different factory loads that were accumulated over the years. The gun wore a modern 1.5-4x20mm scope (Leupold VX-Freedom) . Best results were with the moderately priced American Eagle 50 gr.:
Next trip to the range will be with a higher power scope (Leupold VX-3i 4.5-14x40mm AO) and the goal will be to maximize accuracy:
Use appropriate target
Take my time
Control breathing
Shoot when the adjacent shooters are not shooting
Let barrel cool between shots
Adjust bipod to be steady and comfortable
Rear bag to adjust vertical aim
Consistent cheek weld and eye relief
Concentrate on smooth trigger pull