I like the Cometa rifles for their price! they are a decently built air gun for what u get, ToR that is a very nice looking rifle u have for sure!
I had a few 400's in .177cal and they never shot well! IDK if was the pellets I was using or what but I never had any luck with the .177 in the 400 series
I'd be interested to know what gas spring option might be available. When I had mine apart (fenix 400) I measured the length available to be less than needed for a gamo or crosman one.