I'm seriously considering buying an Anschutz 1827 Fortner Sprint Biathlon rifle. I don't compete, and I probably never will, but I love Olympic quality guns. I shoot often, and really enjoy 22's. I already own a Pardini SP and a Morini CM84E (both Olympic pistols), and they are works of art. I've been putting money aside for my next purchase, and I've always been facinated by those Biathlon rifles. I've saved up enough already, but before I order it, I was hoping someone here might have some experience I can call on. The rifles aren't shipped with a rear sight. I've found the correct rear sight (Model 6827), but is there anything else I need? I've come across a bunch of adjustable irises, metal aperatures, and so on... are they needed? I don't mind buying them if they are, I just want to be able to take the gun out and shoot it when I get it. I've spent a lot of time researching, but there is so little specific information on Biathlon rifle accessories out there. The accessories themselves are easy to find, but I'm sorry to say I just don't know what they're all for. What I want is pretty much the exact same rifle used in the Olympics, with the same sights and so on...minus the back sling, of course. I'd appreciate any imput you guys have.