[Hectic]

Mags will have play on AEG's even high end ones. The real thing even has some play (about 1.5-2mm, not sure if true across all manufacturers or not or all mags, I only fired 3 different guns with 1 or 2 mags in each) the better option is replace the mag catch, if it's an issue that has arisen after a decent amount of use.if it is relatively new then your best bet is to put some loop velcro on the opposite side of the mag catch in the mag well, not electrical tape, yes that's ghetto, like that's a good fix in field if yer in a spot but not the real fix. Unless it is in fact just an oversized mag well (it happens)
The real fix is a combo of 2 things.
1. Good mags that fit your gun correctly (just cause mag brand mags are pretty universal it doesn't mean they play nice with all brands of guns and mag releases)
Also note plastic mags will wear out over time and stop catching properly.
2. A good steel mag catch (that should never wear out unless you run mags just as hard as the catch, not gonna happen tho the spring can wear out a bit and need a stretch, heat, quench to "revive" it)
I personally don't mind plastic mags cause they are light but metal ones will tend to seat beter and don't tend to wear out but you gotta carry em lol.
big caps I find are often an issue. A lot of them tend to be a lil loose in most guns.