Well, I guess I'm sort of a collector as I have a thing for the old military rifles. I think my oldest is a Model 1898 .30-40 Krag-Jorgenson that the Serial No. dates to 1898. Unfortunately it was sporterized at some point, but it's the only one I recall ever seeing on a rack.
I have a Swedish Mauser that dates to 1905, a 7mm Chilean Mauser Model 1895 that I have not yet been able to date. The serial number on that one is E 9XXX, so if you have any resources for dating it I would appreciate it. Both of the Mausers are matching numbers rifles, the 7mm is without import markings as far as I can tell.
I have a M-17 Enfield dated 8-1918 so it was built for WW I but just missed seeing action. I have the two SMLEs and a Sovier SKS from 1953, with CCCP and star markings. And my Colt Sporter which is about as close to a M16-A4 as you can get from what I've read.
There are times when I'll bring just these oldies to the range for what I call "Old School Day". There's just something neat about shooting rifles that are over a century old but still can hit a 9" paper plate (otherwise known as "minute of venison") at 100 yards. Unfortunately, as I've said many times before, my eyes are now to the point where I need reading glasses and I can hardly even see the tiny rear notches on the Mausers and some of the others... but I absolutely refuse to have any of these rifles drilled and tapped for a scope.
Mausers, 7mm Chilean (7X57) top and Swedish (6.5X55) bottom.
M-17 Enfield (.30-06) top and Krag-Jorgenson (.30-40 Krag) bottom.
Soviet SKS (7.62X39) top and EBR (Evil Black Rifle) Colt Sporter Target Model (5.56X45) bottom.
BTW, nice consecutive number Enfields there. The wood looks like it's brand new, issue sight top and target (or sniper?) sight bottom.