I have a Harris bipod and adapter (I think the adapter is a "#6"). Base is an EGW HD 20MOA. My rings are Seekins and I love them so far. I've used Burris tactical rings in the past with no issues, but the Seekins are head and shoulders above them (but more than double the price, too. Keep an eye out on the trader board for a set). I've never used a biathalon sling, but I know TAB Gear makes one. Otherwise, check out Champion's Choice. They may have some, as well. Everybody has their own preferences for cleaning gear, but I will say that I use a Tipton one piece carbon rod for all my rifles ( I got the .22 caliber rod and just switch tips to fit the rifle I'm cleaning). It was money well spent and I've never had to deal with a bent rod since I bought it, years ago.