By taking a partial cross section of a spent .22LR cartridge shell, drilling a hole in it and placing it on the current sight post with pressure down fitting. Thereby creating a front peep site. A dab of kevlar epoxy on top to further hold it in place.
Alternative the top of the front site post can be down diameter-ed and or threaded and a nut placed on top to hold the peep in place.
Only to be made in case of a national emergency concerning homeland security???
© 2017 Thomas Murphy