Again, don't be concerned.  I am not teaching you to ambush anyone.

AMBUSH FIRING WITH THE RIFLE AND THE PISTOL. 

To paraphrase the US Army's "Combat Training with Pistols &
Revolvers, FM 23-35"  when someone is "Ambush Firing", they are
trying to "catch their  target" as the  sight alignment moves past
the target,  and they fire the weapon at that instant. 

Now, an established hunter, and "country boy" recommended that to
me, years ago, and I have used it "right much."  What he was saying
was to pick the moment when your sights OF  YOUR  RIFLE  are best
aligned, and pull the trigger then.

The effect is to try to work around the wobble that everyone has
when they fire a  RIFLE.  I have noted, myself, that the first
instant I get a good sight picture, especially with a scope, is the
best time to fire.  Trying to hold my weapon, and get a better sight
picture, does not work.  I begin to "wobble" more.  

Now, many of you know I sometime say: "I can shoot well with a
rifle, but Heaven Help me  with a pistol."  I have found part of the
problem.  From the above Pistol Manual:

___________  "The firer who is a  GOOD  SHOT  holds the sights of
the weapon as nearly on the target center as possible and continues
to squeeze the trigger with increasing pressure until the weapon
fires. 

The soldier who is a  BAD  SHOT  tries to "catch his target" as his
sight alignment moves past the target and fires the weapon at that
instant. This is called  AMBUSHING,  which causes  TRIGGER JERK.  "
(Capitalization mine.)  _____________

WELL NOW.

Apparently my beloved method of firing my RIFLE does not work with a
PISTOL.  The problem with the pistol is that it is smaller, as a
friend noted, and the effect of the trigger pull is greater.  With
the rifle, you have three good points of contact, to hold things
steady.  With the pistol, you do not, and trying to "ambush" your
target will not work.

The things you learn by reading!  -Paul

Quoted from 
FM 23-35 CHAPTER 2 ( Markmanship Training )
http://155.217.58.58/cgi-bin/atdl.dll/fm/23-35/FM23-_3.htm#REF3h2   Htm format
http://155.217.58.58/cgi-bin/atdl.dll/fm/23-35/ch2.pdf            Adobe format

which is part of
FM 23-35  COMBAT TRAINING WITH PISTOLS & REVOLVERS, 03 OCT 1988  
http://155.217.58.58/cgi-bin/atdl.dll/fm/23-35/fm23-35.htm          Htm format
http://155.217.58.58/cgi-bin/atdl.dll/query/download/FM+23-35     Adobe format