I ran a battery bag on side of stock and used proper sized lipos in my vfc scar h dmr . It was set up as dmr and higher fps on semi .
Be gentle (ISH ) with the selectors as they tend to misslign or break . The selector plate isnt the best either as works with the cogs for fires selectord and wares quick . Gear box is ok till it breaks like any other AEG. CNC hop helps alot as one it comes with is pants . I have Airsoft pro and working well with flat hop etc . If u want cheap mags then u can use SR25 mags from taiwengun. The p mags work a treat too . Just need filing a little on mag catch opening to fit . And they are cheap for £7 each. Anything else just give me a message