I'll lead with I HAVE NEVER OWNED A DOUBLE, NOR DO I INTEND ON OWNING ONE... I thought about it very seriously at one time.. and even did a little shopping.. and then determined I'd be personally better served with a couple of really nice magazine rifles rather than a double....
That said, Ive handled quite a few, and have a substantial number of friends that own and shoot them regularly..
Based on the feedback Ive gotten from them, and from what Ive seen here on AH, of the choices you lay out, I think Chapuis would be where I start.. While not common, I have heard complaints about Merkel from time to time.. and I just dont know enough about the Rizzini options to even know where to start (although they make some absolutely wonderful double shotguns)...
We have a member here that is an invaluable source of information on Chapuis (
@Tom Leoni )... and there are a good number of members here that own and/or have owned Chapuis, and I cant recall any of them ever saying they regretted making the purchase..
Were I shopping for a NEW double DG rifle, a Chapuis in 470 is likely where I'd focus my search..
Were I shopping for a double rifle in general (to include used), my aperture would be opened much more widely.. For example, I've seen some beautiful turn of the 20th century Army-Navy doubles go for only marginally more than a Chapuis or Merkel..
For example there is an Army-Navy 450/400 3 1/4 NE currently on Guns International for $16,495.... that seems a lot more attractive to me than a new Capuis or Merkel.. although since I acknowledge that I know little to nothing about doubles, before I went and dropped 5 figures on a rifle that would likely only get hunted 3-4 times in the rest of my lifetime, I'd be hitting up members like
@rookhawk ,
@Red Leg ,
@ActionBob , and
@Houston Bill for as much information and advice as possible.. I know they all have much better insight and knowledge when it comes to doubles than I ever will..
Army & Navy 450-400 3 1/4 NE Box Lock for sale online.
www.gunsinternational.com
Also understand that FOR ME, I dont really look at firearms as investment purchases.. I do trade, swap, etc.. quite a bit.. but I go into each purchase at least thinking/planning to keep the firearm for the rest of my life.. so I focus far more on what I think I can afford, what I think I really want, and whether or not Im really going to use it.. and focus far less than many others on whether or not I will get my money back out of the rifle or make money on the rifle in the long run..