Blackpool Air rifles is also good as you can pic'n'mix 10 tins of anything and still get get your 10 tin discount, which covers the cost of the postage just nicely
Very good if you have a small collection of air rifles & pistols
If you have just couple of rifles then 5 tins of their preferred pellet each.
I would have a word if you intend to make a larger purchase of pellets as they may give you a little more discount, some shops do some don't. One that does is city air weapons in Lincoln with 20 tins or more. If you're buying on behalf of a club the a letter from the committee will sometime yield a good discount too