I have 3,850 rounds through my daily carry FNS-9. I love the gun but I've accidentally hit the ambi-mag release on the right side of the gun 5 times in those 3,850 rounds causing the magazine to be spit into the ground in front of my feet. Luckily this happened on the range every time and not in a "situation".
I'm a right handed shooter and use a high thumbs forward grip. My left hand grip when shooting .20 - .25 second splits gets tight and squeezes on top of my shooting hand causing the accidental mag drop mid string. I know this doesn't sound like a lot of times in nearly 4,000 rounds but I can't have that happening on a gun that I carry daily.
I called FN and they told me they don't make a non-ambi mag release and weren't aware of anybody that does. I called Midwest Gun Works in Missouri thinking maybe they would know of someone that makes one or have some suggestions for me. They weren't aware of anybody making a non-ambi mag release and thought that taking a Dremel to the mag release may be the way to go.
So...off to the work bench we went. I removed the mag release to do the work. Works like a charm now!