Instruct: Classify Amazon reviews into positive or negative sentiment
Query: great gun easy to mod

this is a great gun out of the box i modded mine custom valve, 14.5 inch barrel ,the 1399 stock turning it into a great carbine it`s firing at 686 fps now can put 10 shots in a circle the size of a quarter at 30 yards and it hits hard can take out a pest no problems great gun for the money and greater yet with a few mods