Leupold 8.5 x 25 is NOT a 50 yard rimfire scope. The lowest Parallax setting is 75 yds (I might be 5 feet off, but I have no clue where put the email from Leupold concerning the parallax on that scope). It's a great scope for centerfire benchrest, if you have the space to mount a 50mm scope. I have one on my 243 BR rifle and it's perfect for 100 yards and further.
If you want to shoot some occasional 50 yard matches, and also do some long range shooting, most people use a 6.5 x 20. Leupolds EFR has parallax settings from 40 feet and up. If you shoot IR5050, your legal with the scope set on 6.5 power. I have an EFR on several guns, including my IR5050 Sporter. If my Heavier guns malfunction, I can at least shoot the last two targets with the Sporter scope set on 20 power.
I hope that helps
Gene