Somebody asked what will fit in the Maxpedition Fat Boy.  I always keep a Glock 23 in it, so I decided to retry to see what fits.

Glock 23? Yes, you don't even need the holster strap (I have a velcro strap that I use, not the official Maxpedition one).

S&W M&P fullsize? Yes

Colt 1911/Government? Yes, although I didn't think it did. I seem to remember the zipper catching on the hammer/beavertail.  I wonder if when the bag was new it was stiffer and didn't work. One thing to note is that my Colt is series 80 style with a classic round ring hammer and stock (pre-duckbill) grip safety. Big grip safety tangs or fancy hammer? That may not work.

S&W 1006/4506? Nope.

S&W 1066/4566? Yes (5900's should fit too)

Sig P225? Yes

Sig P220? Yes, I thought not, but it seems to. Doesn't extract well with Hogue rubber panels (duh).

FN FNX? Nope, hammer catches zipper

Browning HiPower? Yes, suprisingly with ease

3" K/L frame? Yes

4" K/L? Nope, well, at least not with fullsize Hogues, or wood presentations

Smaller pistols will, of course, fit but you definitely will want the optional "holster" which is a velcro loop (or similiar) to angle the pistol so it can be withdrawn easily.

Hope that helps!