by ~ » Sat Feb 26, 2011 2:03 pm
The flex of a barrel is essentially the point of a "pet load": after a handloader decides on a bullet type/weight suitable for particular application, he starts with a powder type/mass from a table (manual) to give him the velocity range he wants, and then he varies it systematically to produce the most consistent barrel harmonic in his rifle.
Of course there's lots of other things he can vary - primers, case shoulder, bullet seating depth/rifling engagement, etc. But the point is to have a bullet leaving the barrel at the same point in the barrel's oscillation every time (which usually involves some compromises).
Handloading is an exercise in amateur process control. It's lots of fun giving theories an empiric workout, and shooting for accuracy and precision is deep meditation.
"...This is the doctrine he was wont to teach,
How divers persons witness in each man,
Three souls which make up one soul: first, to wit,
A soul of each and all the bodily parts,
Seated therein, which works, and is what Does,
And has the use of earth, and ends the man
Downward: but, tending upward for advice,
Grows into, and again is grown into
By the next soul, which, seated in the brain,
Useth the first with its collected use,
And feeleth, thinketh, willeth,—is what Knows:
Which, duly tending upward in its turn,
Grows into, and again is grown into
By the last soul, that uses both the first,
Subsisting whether they assist or no,
And, constituting man's self, is what Is—
And leans upon the former, makes it play,
As that played off the first: and, tending up,
Holds, is upheld by, God, and ends the man
Upward in that dread point of intercourse,
Nor needs a place, for it returns to Him.
What Does, what Knows, what Is; three souls, one man.
I give the glossa of Theotypas ..."
from A Death in the Desert, Robert Browning