Thank you to all who have posted & PM me with info & thoughts , much appreciated !

Here is a target shoot at 5o yards , 2 softs & 2 soilds

And here is a full Nitro 577NE Greener double rifle action I saw some time ago , with the reinforcement strap , I have seen on another , so might be factory ?

The action LOOKS very much like the shot gun action , but I don't know size & weight of action .

Thanks to all !