Tone, I don't normally recommend drop in rams as the two I've had in the past (Theoben AWT units) have both leaked (I'm sure I still have one of them kicking about in the loft), as I've always mentioned (and one reason why I like springs) is you can't adjust the power of a drop in ram (thus why I'm asking now), I was always put off rammers many years ago by Tony Wall at SFS as he told me some right horror stories about them (leaking, different temperatures causing power fluctuation) , I've always liked a rammer and the little faux pas I made early on in the year with my Theoben and trying to convert it to spring (should have just left it alone but my daft brain comes up with some crazy ideas sometimes), but I've read a lot of different reports recently about how different rifle makers are using drop in rams to good effect, the main body of AWT rams I had would slip into the piston body itself and the rod would contact the rear of the cylinder, most of the newer rammer models being produced including the Diana N-tech models are turning the ram around and having the rod in the piston and the main body touching the rear of the cylinder (like the ram I've just fitted), I believe fitting the ram this way reduces the recoil and quickens the piston up as it doesn't have the weight of the rams main body in the piston (but if I turned it around, I wonder if it would increase the power due to having a heavier piston?), I remember seeing on the Theoben site once saying you shouldn't fit washers to preload the ram and you can't cut the rod to reduce power either.

As for the Gamo spring tuning kit, I have just taken out my welsh willy kit, which actually transforms the rifle from the standard spring set up, the new rear guide is one piece and is stepped as it needs to make room for the trigger housing slotting into the cylinder, there is no twang from the WW kit (mainly because Will makes the guides to fit the springs) and it fires almost the same as it does with the ram fitted.

Hope that helps mate, if you want any more info then just ask.

Pete