While you are on the site, in your browser find and click "Add to Home Screen" A CGN beaver app icon will then be created to your phone that is directly link to the site.
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I use one in my Colt SP2. My Dlask doesn't need one.
For a field expediant, you can whittle your own "accuwedge" out of a pink (ok) or white (ideal) rubber gum eraser. The Staedtler "mars plastic" erasers seem to work best. Just cut the rectangular eraser block in to an L-shaped approximation and then start fiddling. About a $1 each at the dollar store. Everyone has a spare eraser somewhere.....
My homebuilt with stag lower/armalite upper is tighter than all get out as is, I don't dare try to make it tighter! I usually can't push out the takedown pin without a punch. No rattles, no slop no nothing. Just TIGHT!