Let's start with hical, that is just a bad plan and is IMHO worse than before. A cheap vertical grip is more likely to break than anything.
As for your hand slipping... This is where trigger control comes in. You could also shoot yourself with a handgun or you could trip and fall... Or maybe you could get in a car crash on the way to the range. Relax, be safe and have fun.
The Tapco or FAB fore grips are very sturdy, they keep your hand in a safer location & provide more control. However they arent everyone thing.





















































