First tune questions

[jml]

Hello everyone,  I would like to take apart my Gamo Big Cat and tune her up.  I thought about a lube tune but once its apart I might as well change the spring and seal.  Can anyone recommend the proper spring and seal maybe in a kit?  I don't really want to loose power but I don't want to sacrifice accuracy either.  The rifle is only 1 month old.  It used to shoot PBA pellets (the ones that come with it) supersonic but no longer.  I shot 5 or 6 of these when I first got the gun along with a tin of CPHPs and a tin of Destroyers after about 700 or so rounds the gun felt a little different to me,  when I tried the PBAs again there is no supersonic crack.  Is it normal for a gun to loose power after 700 rounds?
Any advice would be greatly appreciated!
jml.

[ezman604]

James, welcome to GTA Forums. Glad to have you aboard.

The PBA ammo is not recommended for any magnum class AG. They are very light and have such lower resistance that shooting them can cause powerplant damage or failure. It's a big advertising gimmick to tout a gun at 1000-1200fps or more output with this ammo. But, they don't bother to tell you what damage it can do, plus the fact that you will not have reliable accuracy and almost no knock-down power down range. I'm afraid you may have damaged your BC already but a teardown will be needed to find out.

I don't own one and haven't had an opportunity to tear one down so I can't vouch for what spring and seal will work for them. You can do a search of The Shop forum for Gamo BC and see what you can find there. Several members here have these and I'm sure several will respond to your post with the info you need. You could also consider sending it to Gene for a tune job. He can probably turn it into a sweet and powerful shooter.

Again, welcome to GTA Forums.

Happy Shooting!!!!

Dave

:emoticon:

[jml]

Thanks for the reply.
  What is the point of putting them in the box?  When I say I shot 5 or 6 PBAs I mean it.  How can shooting that few do so much damage?
  I did shoot it out in the cold and thought that might have done some damage.  I was wondering if the Destroyers were part of the problem also, they seem to fit loosely in the breech.  I hope not because they were the best pellet I've shot in the BC.   Anyway, I was hoping to have a new seal and spring before I took it apart.  Can anyone suggest a spring/seal combination?

[ezman604]

Well, damage can be done with 1 shot. Not usual but possible.Your Catmay have had other issues already, like a torn piston seal or something. Check this thread http://www.gatewaytoairguns.com/airguns/forums/thread-view.asp?tid=20146&posts=11&highlight=GamoBigCat&highlightmode=1#M161744for info on the spring and seal from JM to fit your Cat.

They put that ammo in the box for several reasons. First, to back up their claims for the fps output. Secondly, IMHO, these are not a high selling item and they have to find a way to get rid of them. Tax write off???

Or thirdly, IMHO, as another promotional tool. If you're impressed by the speed output and nothing else, you will buy more of this type of ammo.

There's a lot of useful info here and many helpful members. There are quite a few Gamo BC owners here that can help with specifics on this one. But try a search of the entire site for Gamo Big Cat and see just what is available.

Good luck and Happy Shooting!!!!

Dave

:emoticon:

[jml]

I really appreciate your help.  Thank You!!!