I don't think inner barrels increases "accuracy" but it do increases fps by 5-10fps and your effective range's grouping. If you want accuracy, you'll have to upgrade things that plays along with hop ups and adjust. Takes a while for you to find the sweet spot. A very very good brand if you dont want to spend a arm are madbull's python ver.2 , i heard modify hybrid isnt so bad either. Check put airsoft parts.ca or smtg like that!! Some people might ask you to get the "twisted japanese barrel" but its about 120$ versus 30-40$.