Originally Posted by skiball83
Mine was out about 4 inches when I installed it. Dont know how long it is now as I havent had to take anything apart yet. All I know is it was a pain in my @$$ but I got it in. Like turtle said its a great firing spring and really smooth, I just want to bump up the power about 50-70 fps if I could. Any gain will be good. Unfortunalty I dont have a chrony. Never needed one until now. Ill have to put that on my "Get It" list. About those spacers, what size should I use. Checked out ARH and found regular spacers and power spacers. Dont know what will fit. The spring feels like it could be compressed a bit more.
Skiball, 50 - 70FPS is a lot to ask for the E3650 spring. I think it is a little bit softer than the stock spring but the material used is better than the typical Chinese springs. If you really want to make your Big Cat "hotter" I suggest you play around with the stock spring and a new top hat / rear guide material. If you want the Crosman Quest spring is a good replacement for the Gamo's.
I never tried bumping up the speed of my G-1 with the E3650. It's always Accuracy then Speed for me when I play around with my airguns. One of the weirdest but very rewarding experiment that I did was testing a very short spring on the Crosman G-1 Extreme. I cut the stock spring in such a way that I totally have no preload at all on the spring when inserted on the system. I got about 570FPS and the accuracy at 10 yards was the best that I got. I documented everything on my small airgun notebook for future reference. I had no choice but to put the E3650 spring back since I am testing my own ability to shoot at farther than 10 yards. The E3650 with Mike's custom top hat/rear spring guide gave me that needed Oooommpphhh to send the pellets straight up to 50 yards hitting a small plastic bottle measuring 1.125" wide X 3" tall. With just a light wind breeze I get lucky hitting it 3 out of 5 most of the time. My recorded muzzle velocity is about 850 - 870FPS with the E3650.
If you really want to get serious about airgun tuning or tweaking you can't cut corners so you really need to buy a chrony (or rent one if that is possible). I'm using the Chrony model BETA. I made my own modified switch that I can connect to the mini jack input to access all the data rather than doing all the computation manually. You won't be sorry owning one. The wealth of info that you will gain about your guns with a chrony is immeasurable.