I don’t know of anything but if you could grind the head of a bolt down so that it would fit into the metal channel running under the forearm you could then fasten a small piece of wood to which you could attach a picatiinny mount. That would work. Me if just get a Caldwell bag and use that.
Go to Rapid Air Weapons web site they have a Euro rail to Pic rail adapter that bolts on gun and your done for $35.00 kind of expensive but it is an option. Double check for fit on Euro rail side. Hope this helps. MM
Thank you for the reply’s. All good advise that I appreciate. Feel confident that I could make the adapter up as you have suggested marflow. I have a flat based length of picatinny so I’ll give it a go.
I agree the Accuracy International adapter is to expensive for what it is.
I used to make my own tee nuts for rail accessories until I found these Rectangular Tee Nuts at ACE Hardware. They fit perfectly although you will have to either grind or file the thread boss so it doesn't protrude above the rail, or drill a recess for the boss in the rail accessory. I always drill the recess in order to assure good thread engagement. This shows the fit to the rail of a 300S. They also fit the Anschutz rail.