I have a 600mm .177 barrel arriving today for my FX Crown and would like to set it up for shooting rats at 50 yards. I have searched the internet and it doesn't appear there are any U.S. based vendors that are currently offering .177 slug samplers. I'd really like to try a variety of weights and types to determine the best performer before investing in 400 - 500 count tins only to find out they won't work for me! Any help would be greatly appreciated!