#10 Remington caps work perfectly on all the nipples I've bought from Thunder Ridge, have no fear.
The Treso Ampco nipples I have in both my Walker and Dragoon and they take 10's perfectly. Just call them up and tell them what you need and they will be more than happy to help out. Sometimes orders take a bit of time from them as they are a small mom and pop shop but I have always been happy dealing with them
I also use their TRM brand nipples in the rest of my Ubertis and Piettas and even in my 2nd Gen 1860 Colt Army. All take #10 Remingtons perfectly and without a hitch.
It's really nice having the same size nipples and caps for everything and especially when they fit snugly and you never again have to worry about pinching caps or having them fall off etc.
