I added a Radian Raptor Ambidextrous Charging Handle and a Trijicon Tritium Front Sight Post, but I still haven't fired the shorter rifle. The popup sights, the Bushnell TRS-25, and the LASER bore sighter all seem to line up well. The red dot is coincident with the Trijicon dot and centered in the small rear peep sight, so it should work for close range.
I really like the Raptor for working the bolt... much easier... and from either side or both.
The AR-15 front sight tool I bought(upper left in photo) doesn't seem to fit, but Trijicon included a thin-walled sight tool with 4 and 5 prongs which works well with the 4-pronged end.
For home defense, I think I'm better off with the red dot sight. It's lighter and makes for a cleaner-looking weapon system. I haven't sold the 20" upper and still think about just mounting the scope on it, but would rather sell it.
USAF Retired '88, NRA Life Member. Wife USAF Retired '96 Avatar:Wynn re-enlists his wife Desiree, circa 1988 Loring AFB, ME. 42nd BMW, Heavy (SAC) B-52G's
Frédéric Bastiat’s essay, The Law: http://mises.org/books/thelaw.pdf
Thomas Jefferson said
“A government big enough to give you everything you want, is strong enough to take everything you have.”
and "Peace is that brief glorious moment in history when everybody stands around reloading".