Cheers for all the replies. SideleverJohn sent me the dimensions of one of his springs -9mm long x 2.3 mm OD , I went to a local engineering supplies and picked up a few and the guns all working fine now. Luckily I got a few that I could trim to length as mine needed to be a bit longer than 9mm ' think I'm currently running about 15mm long and the springs I fitted were 2.7mm OD . Can always try trimming length to suit. If anyone ever needs any of these springs I've now got a supply of these so feel free to message me if you need one.