I have one on my 500 and have no issues with it at all, as far as being not recommended from the factory I have never heard of that. The one I got for mine fits it like it was made for it by mossberg themselves. I have the tacstar one.
Ok that works, I have put many on different models for other people, sometimes you have to make some minor modifications for it to fit and work right but that is usually rare, I will be able to tell more from a pic.
Is the use of a side saddle on a mossberg 500 not recommended by the factory ? Because of the aluminum recover and the face that it is inside the gun?
If it's not reccomended by Mossberg, it is probably because modification of the gun voids the waranty. Plain and simple. I know a lot of folks who have run side saddles on M 500s with absolutely no problems at all.
Is it better to do the right thing for the wrong reason, or to do the wrong thing for the right reason? If you do the wrong thing for the right reason, is it still the wrong thing?
Si vis pacem para bellum.
There are two ways of doing something. Right and again.
I have a 500 and 590A1 both have had side saddles on them for years without issue.
Never heard of Mossberg recommending against it. If they do it is probably a warranty issue. Or liability issue in case some idiot installs one wrong and hurts himself.