After a lot of trial and error, I feel I have made a good bolt hold open device.
Just grab the charging handle with 4 fingers, pull all the way to the rear, push the pin with your thumb and ease forward and bolt is locked to the rear.
Just pull back slightly on the handle, spring loaded pin pops up and lets her slam home. Just that simple.
Parts are made from chrome Molly steel and between the 5 operations of lathe and mill work on each set it takes about at 1/2 hr. to make.
Outside tube is welded to charging handle.
Right now the price is $40.00 for the parts shipped , welded to your charge handle is $20.00 more.