When the Army tested the Carcano, using 3 expert marksman, they concluded a person would need considerable experience with
weapons and considerable experience in paticular with the Carcano to make the shots proposed by the WC.
Aside from the scope being misaligned and needing shims added before it could be adjusted and the iron sights being sighted
@ 200mtrs, which caused the rifle to fire high at lesser distances, they found two other dificulties when firing the Carcano.
First, the difficulty of operating the bolt caused the shooter to take the sights off the target when cycling it between
shots.
Second, the two stage trigger of the Carcano created a hair trigger during it's second stage of firing.
They concluded the shooter would need live firing practice to overcome these difficulties.
https://www.maryferrell.org/showDoc.html?docId=39#relPageId=449&tab=pageWarren Commission Hearings, Volume III Current Section: Ronald Simmons
~snip~
Mr. EISENBERG. Do you think a marksman who is less than a highly skilled marksman under those conditions would be able to
shoot in the range of 1.2-mil aiming error?
Mr. SIMMONS. Obviously considerable experience would have to be in one's background to do so. And with this weapon, I
think also considerable experience with this weapon, because of the amount of effort required to work the bolt.
Mr. EISENBERG. Would do what? You mean would improve the accuracy?
Mr. SIMMONS. Yes. In our experiments, the pressure to open the bolt was so great that we tended to move the rifle off the
target, whereas with greater proficiency this might not have occurred.
~snip~
Mr. EISENBERG. When you say proficiency with this weapon, Mr. Simmons, could you go into detail as to what you mean--do
you mean accuracy with this weapon, or familiarity with the weapon?
Mr. SIMMONS. I mean familiarity basically with two things. One is the action of the bolt itself, and the force required
to open it; and two, the action of the trigger, which is a two-stage trigger.
Mr. EISENBERG. Can familiarity with the trigger and with the bolt be acquired in dry practice?
Mr. SIMMONS. Familiarity with the bolt can, probably as well as during live firing. But familiarity with the trigger
would best be achieved with some firing.
~snip~
Mr. EISENBERG. Why is there this difference between familiarity with the bolt and familiarity with the trigger in dry firing?
Mr. SIMMONS. There tends to be a reaction between the firer and the weapon at the time the weapon is fired, due to the
recoil impulse. And I do not believe the action of the bolt going home would sufficiently simulate the action of the recoil
of the weapon.
Mr. SIMMONS. Yes. But there are two stages to the trigger. Our riflemen were all used to a trigger with a constant pull.
When the slack was taken up, then they expected the round to fire. But actually when the slack is taken up, you tend to
have a hair trigger here, which requires a bit of getting used to.
Mr. McCLOY. This does not have a hair trigger after the slack is taken up?
Mr. SIMMONS. This tends to have the hair trigger as soon as you move it after the slack is taken up. You achieve or you
feel greater resistance to the movement of the trigger, and then ordinarily you would expect the weapon to have fired,
and in this case then as you move it to overcome that, it fires immediately. And our firers were moving the shoulder into
the weapon.
~snip~
