I have experimented...
I've experimented with reduced loads in pistols and the only problems are possible erratic ignition, lousy burning and sticking a bullet in the barrel. Also it used to be that jackets would come off bullets and stick in the barrel. Today's bullets are bonded better, but I'd still be wary of this because all bullets aren't created equal. As far as I'm concerned the stuff about reduced loads causing 'detonation' is a lot of hooey but if you stick a bullet in the barrel and fire again all bets are off. It can cause nothing, to 'ringing' your barrel, to bad damage to the gun and you.
I've also experimented with reduced loads in rifles, but only according to manufacturer's data. Rifles are a bit trickier. I believe the above still applies, but there are ways of getting reduced loads in rifles using published data with different powders, even some pistol powders in certain cartridges.
Presently I'm trying to make a reduced load of a 147 grain Bayou coated bullet using Acc #7 for easy recoil to introduce my wife to semi autos. I'm down to 4.6 grains, it operates the action on my 3rd gen just fine and I believe I can reduce the load even more. I wasn't optimistic at all about using them in my new(old) Keltec P 11 but I was testing the gun so I gave it a try. No good. It didn't like lead SWCs at all. I'm going to try 4.3 grains next. One thing about these light loads is that they are easy to shoot and accurate, partially because the gun is easier to control on follow up shots.