My M16 runs perfectly on semi auto, does it mean that it will also cycle as reliably on full auto? i don;t have a place to test it since most ranges does not allow full auto fire. Thanks.

If you have a select fire M16 than it should run fine on automatic.  You will have to learn proper trigger control to fire off 2-3 round bursts.

You can do a function check of the full auto parts with a unloaded weapon.  Remove mag and double check clear chamber.  Rotate selector to auto, hold trigger back and operate bolt several times.  Hammer should fall every time bolt goes forward.  Do the same with semi and hammer should lock back and not follow bolt forward.

You could have a bolt bounce problem, and it would not show up in semi-auto, only in full auto mode.  Feeding, extraction, and ejection should be the same in semi or full.

What does it do? Fire one shot and not reset, short burst and not reset or hang up?   Don’t get me wrong but it sounds a little like a Stock AR15 that has some M16 internals in it…..

It probably won't work in full auto!  The technology is just not there yet!

No it does not mean it will be equally as reliable.  Do you have a DIAS or RR gun?  If the auto sear is worn you could have reliablity issues that would not show up in semi auto mode.