Mag parts are a b1tch to find in th eUK these days,i find it easier to ship from the US
For used automag parts at a good price and a hassle free purchase from one of the nicest guys around to deal with check out Mcarterbrown.com
Find on the memberlist and message "Bacci paintball" When ever i need mag parts i'l always go to him.Takes about a week from Nor Cal.
His name is Dan by the way and he is happy to ship to the UK.
Alternatively there is always Fatbobs paintball in yorkshire,they are the sole stockists of AGD parts in the UK that i can find.
Hope that helps,keep them mags rockin!!
Chris