What problems are being reported with them? What problems have you personally experienced?
I have personally experienced zero problems with my gun that were a fault of the gun (I will explain below*). I have heard one, maybe two stories of catastrophic failure involving a Rhino. The one I remember involved a recoil shield separating from the rest of the frame. There were pics and all that. It might have even been posted here at THR but I can't recall.
* I should have posted this with my original reply, but oh well. When I bought my Rhino I was eager to shoot it but out of ammo, so I loaded up somewhere in the neighborhood of 3,000 rounds of .38 Special for it and my other revolvers. Unfortunately I failed to detect a failure on my reloading press which caused around 50 of those rounds - confirmed much later - to be assembled with no powder. Normally this would have been no big deal in and of itself as I tend to be somewhat particular about checking for abnormalities while shooting. I also usually don't assemble so much ammo at one time but I was preparing to make a fairly large move to another state and I wanted to minimize my loose components (having moved at least 6 times with my reloading gear I can assure you it is a royal pain). It was a mid-range .38 Special load that I had used quite a bit before so I wasn't worried about it. Keep in mind I had no idea there was any problem at all - as best as I can tell, the failure on the press occurred right at the last 50 rounds. When I set up the press at my new location I noticed some things were out of whack with the press, but there always seems to be stuff like that after my gear has been jostled all over during a move.
Several months after moving I was at the range with my Rhino and I'm sure a gaggle of other weaponry. I was practicing rapid 6-shot double-action strings. Somewhere in the middle of the string I heard a small "pop" but I was too quick on the trigger and so this was immediately followed by a giant BOOM! I distinctly remember seeing flames coming out of the cylinder gap past both my shoulders.
Obviously I had squibbed a bullet. As best as the gunsmith and I can tell, the first bullet lodged right around the mid-point of the barrel (which also happens to be a 2-piece arrangment) and the second one slammed into the first.
The barrel on the Rhino is actually a steel insert in the aluminum frame. When the gunsmith called me I expected the worst. I glumly went to his counter expecting to pick up the ruins of my Rhino. Instead he informed me that not only did he get both bullets out without damage to the gun, but that there was no bulge in the barrel! I still have those bullets today in the Rhino's case to remind me to be careful. There have been no accidental squibs created on my bench since then.
As a result of this near-disaster I ended up going down quite a rabbit hole with squibs. I was able to narrow down the pile of suspect rounds mostly, although I still found one or two the hard way. More importantly to my squib education I went about purposefully MAKING squibs in various calibers to learn more about them. I discharged a total of 43 rounds in at least 5 calibers knowing good and well there was no powder in them. To this day I carry a purpose-made squib rod in my range bag. Most recently I created some 9mm squibs to help member
@Union St with a novel he was writing. If I ever find my notes (or redo the squib testing) I may one day create a thread here detailing it.