GBB Slide locking question
New to Airsoft (just got into it since I've joined). Today when I was showing my Wife how to use a few of my Pistols I noticed that when I put some gas in the mag and load it into the weapon and rack the slide, I can only shoot once before the slide locks back in the empty mag position. My question is, obviously because there's no BB's in the mag it's technically it's empty, but I remember on numerous occasions when at TA buying them the clerk would dry fire it several times (without ammo) to assure me it's in working order. Yet when I try this myself I get one shot, slide lock?
Maybe I'm using too little gas? I wanted my Wife to dry fire the new Glock to see if she'd be happy with the recoil etc. but I only used a few quick seconds of gas, just wondering if that's the issue. I'd check myself right now but I'm not at home and this has been bugging me all day! lol Thanks guys.
ICS M4A1, King Arms M4, G&G TR4-18, WE Glock 17, WE Glock 23F