I've had two AWT drop in rams and both have lost pressure over time but unfortunately you can't pump them back, I currently have a Theoben Sirocco 2000 in .177 and it's lovely to shoot, when I received it at the beginning of the year it was doing 10.5ftp which is the ideal power for .177 and makes them shoot sweet, I've hardly touched the rifle all year as I've not been out hunting due to work commitments and have only had a few shots in the back garden when fitted a different scope a few months ago, so I couldn't tell you what power it's doing now or if it's held pressure over the summer, if I remember I'll chrono it soon and find out if it still has air in it, I think with Theobens, you either get a good one or a bad one, this is my third rammer and the last two never lost pressure.

I was always told many years ago by a well known gunsmith not to use drop in rams as they fluctuated in power because of different temperatures effecting the gases in the ram, so I've always left springers as they are and just used the proper rifles if I wanted a rammer.

Pete