Old cometa-300

[Nick Jones]

I have and old comets-300 in .177
My dad gave it to me when I was about 12 and I’m 40 now so it’s got some age on it. Does anyone know anything about this gun? If it’s a good one or not?  All I know is I’ve never had a scope that would sit still on it. They always slide off the back of the dovetail mounts and it has quit the recoil. Still manage to kill a few squirrels when I was growing up though. Any info on this gun would be greatly appreciated.

[Roadworthy]

Type cometa 300 into your search engine.  You'll get a number of results.  As far as the scope sliding off the back, I assume you have dovetail mounts.  If you have a scope stop screw, use it.  I had that problem with my Diana 35.  I cleaned the dovetail grooves and put in blue Loctite.  I installed my scope mount and torqued to about thirty inch pounds then let it dry.  No more movement.  BTW, the scope mount moving to the rear is caused by the second recoil where the piston hits the end of the compression tube.  If your power is low it may be time to consider a new piston seal.

[AmBraCol]

 Hey, Nick!  Yes the Cometa 300's are good rifles.  I have a couple of them in the herd.  As mentioned, you can apply loctite to the jaws of the scope rings, torque them properly and let dry.  Same problem with the Fusion, by the way.  That's a weak spot in the Cometa design. You should be able to have a scope stop hole drilled, if you know anyone with a proper machine shop setup.  You can replace the seal with Crosman seals for the Optimus and the same for the mainspring, if needed.  OR (my preferred option) you can go to Air Rifle Headquarters and obtain seals/lube/spring from him.  I've used both and both have their arguments in favor of using them.  I prefer to reduce the power a bit, they are sweet shooters when you don´t try to make them into a Magnum Buffalo Rifle.

[Mark 611]

Late to the party, but I have a newer 300USC I have the same problem with the scope walking off the rail, I decided to drill a stop pin hole in my tube and that fixed the problem! I also have 220 Compact in .22cal that did the same thing, so I did the same to it drilled a stop pin hole in the tube! problem solved! my 400's for whatever reason I have no issues with scope movement! they put.