I've had my ROA since March 1986, and have put hundreds of thousands of shots through it in that time - literally. Running a BP course with five or six shooters all getting around a hundred shots each, and I've run seventy such courses so far, means a lot of shooting. Plus, of course, guest days, gun-club noobs and my own shooting..
The ROA is THE definitive modern version of the Remington Model of 1858 with all the benefits of modern technology - coil spring and stainless steel and easy to dismantle and clean. Very accurate, and designed to take the heaviest loads practicable. Shoot ball or conical [ball is more accurate, trust me on that] and has been known, not in UK, to dust both sides of a 300 pound hog at around 25 yards.
I started out from the onset casting for it, using the Lee for ROA .457 mould - do NOT try and second-guess the diameter based on your present experience - .457 IS the size, and that's it. Nothing but lead, either - the best you can get. If the ball does NOT weigh 146-148gr, then it's NOT lead. Do a search on this forum - I've posted literaly dozens of posts about this fine pistol. I recommend that you read them. You mention Linotex, a material I am not familiar with. I'll just reiterate my advice - the ROA was designed to shoot a pure lead ball or conical bullet, not a metallic alloy material of any kind - s'up to you, though, if you have experience of doing better with it than lead.
Loads are entirely up to you, but for paper-punching a light load is good - around 25gr of FFFg suits most. Step it up a bit and shoot the same volume of Pyrodex P or Triple 7, and things get a bit more oomphtious, as you can see by watching my movies on Youtube - tac's guns Ruger Old Army. Top loads are around 40-45gr of a compressed charge, but only a masochist would enjoy shooting them at paper. Most like #11 caps, but some use #10 or even 10.5 - hard to find here, I'd guess. And HOT - the hotter the better, particularly if you shoot the subs. RWS HOT are the best I've ever used, on BP or subs.
All I can say is that with almost half a million of them made, it's a real surprise to find that Ruger has reneged on the supply of any spare parts. That is a fact - there are NO spares at all.
Replacement nipples of the correct hexagonal style are made not far from where we are in Oregon, by Butler Creek/Uncle Mikes, and are readily available at around a 1/3 of the price charged by a UK company, plus mailing charges. If you buy theirs, made in Italy, you'll also need to buy a new nipple wrench, too, adding to the already enthusiastic cost of around £32 plus shipping. I usually buy a spare set or two when I'm over there a couple of times a year for my fellow shooters in our club, where there are a goodly selection of them. For when anything serious goes bad, I have another couple of complete guns over in Oregon to use for bits - something that many shooters of my acquaintance have done, but as I noted in the beginning of my post, apart from nipples that eventually wear to large, little or nothing esle has ever gone amiss. I've replaced them ONCE in 26+ years, BTW. Over in the USA Treso make them out of a kind of bronze material, and they are around 35% of the UK price and look spiffy too. There is a short base pin unit that can be used if you have a bench loader, and load the cylinder out of the gun - some do, some don't. I don't. They are about $45 over there, and around £60 here - plus the bench loader, of course.
I hope that has convinced you to join the near half-million of us who enjoy our ROAs - for sure there will never be anything like it again, and Ruger need a solid kick up the a$se for ceasing production back in February 2008.
tac