At a recent club session a different rifle was brought to the range that had a semi transparent foresight tunnel and the clear element.
One of our instructors asked if it was possible to make these for the BSA Silver star. Based on this one night whilst sat watching the tv. I grabbed the laptop and attempted a replica of an existing black foresight tunnel with my own twist.
Printing this one in resin to eliminate the layer lines on view. I also designed a foresight element that was transparent mirroring the element that is supplied with a std rifle purchase and also a full face. Not expecting these to come out very clear.
To my suprrise I am actually shocked at how well they came out. A little bit of tinkering later and managed to sort the small flaws I had in the first 2 prototypes for the tunnel but the elements were a success after first print. The elements needed some light sanding with a 3000 grade wet and dry and a light coating of clearcoat but overall I have been impressed except for maybe not letting the clearcoat dry for long enough. 
Next is to try it on a rifle on the range. If all is successful then I will start to look at supplying foresight elements to order based on specifications for both 18mm and 22mm sight tunnels.
