The bean counters at Ruger pulled the plug on it because it wasn't profitable enough. They are one of the best patterning guns I've ever seen and they also have a bit of recoil. One comes up for sale about every 6 months on this site.
When I took a Ruger Armorer's class (don't laugh-they are getting into the Law Enforcement market), the trainer, a LONG time Ruger employee said the gun was made to satisfy one of the really old heads that had been with Bill Sr for many decades.
As soon as Bill passed away, the bean counters DID pull the gun. The "corporate line" was they could not get good wood.
They do seem to boil a bird. Maybe straight rifling DOES work.
I local shooter bought one when they first came out and Ruger had it more than he did. I don't know his exact problems but he said it had been sent back 4 times the first year. He ended up unloading it the next season. I don't know if his experience was common with others but maybe he should have kept it since they only made 300 or so.
I own one of these and shoot it every week. I have NEVER had an issue with the gun malfunctoning.
The only problem that I had seen is that it does have little bit of a heavy recoil. Not as much as the Gold Label though. I put a Soft-Kick unit on it and I can shoot 500 round a day and never have a problem with felt recoil.
I have taken the barrel of the Trap Model and but it on one of my Red Labels and use it as a combo. 28" over and under and a 34" unsingle. You have to make sure the the barrel fits just right or you can cause yourself more trouble than you need. My 28" Red Label barrel happens to fit perfect. The only other thing to be careful of is if you pull the trigger twice the top firing pin will put a dent in fill piece that goes were the upper barrel would normaly be on the unsingle barrel.
As I said I shoot the gun all the time and have very good luck with it.
As far as I know they only had around 134 of the Trap Model go out the door.
I also heard the same thing that Shooting Coach said about it being the pet project of one the old employees who was a friend of Bill senior. They also did have some trouble with the wood fit.
If I had a chance I think I would buy a second one.