Chronograph

O

OverPressure

New member
I use my 1911Gold Cup to Chronograph my 45acp rds. Every first shot is always hot. By this i mean if i have a load that averages 850 fps and i
Chronograph 10 the first one out the barrel is 880 or so.

If i were to do a second 10 shot string this wouldn't be the case.

I brought this up with some guys at the range. One individual acknowledged
that this was common for him. His buddy didn't want any part of it.
I didn't ask about the type of weapon.

I am not sure i want any part of this, but here we go!!!

I can hear and feel the difference. Is there a heat generation situation that
is causing this or some other mystical presence i am unaware of?

Go easy fellas there are some local people in the religious right that aren't to
happy with my morals and ethical comments about their beliefs.
"Do Un To Others If The Opportunity Presents Itself".

For those of you who believe in a higher authority I haven't discounted the
possibilty of somebody elses god showing up on my range days!!!
 
Didn't Say What Religion

Just The

" Do Un To Others If Given Opportunity"

More of Character Observation!!!

Nor Did I Deny An Exsistance.

Hey , their leaders may have made the same observations!!!
 
I know two possibilities. (Chronograph operation without divine intervention.)

Powder position: if you start with the muzzle up and lower it into firing position, the powder will be next to the primer for better ignition. Succeeding shots with the powder shifted by recoil won't get quite the flash. This is readily tested. IDPA power floor testing requires raising the muzzle before each shot to insure maximum velocity.

Cold/clean/oily barrel letting the first shot zing out faster. Related to the rifle phenomenon of the first shot not landing in the group with successive shots. Target shooters need fouling shots about as much as sighting shots. I know smallbore shooters who will rapidly dump four or five shots into the berm before firing a carefully aimed shot.
That would be more work to test, but many hunters and snipers go to great lengths to determine their first shot zero.
 
An 880fps first/clean/cold barrel shot relative to a average of 850 thereafter is not abnormal at all.
In fact I tend to discard that 1st/C/C velocity when figuring the average.
 
Does anyone really think an 880fps 45 round is going to impact any differently/effectively than one at 850fps?

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An insignificant effect on TRAJECTORY at pistol ranges, but there are too many reports of wide first shots to just ignore.
 
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