General RE LEE
Well-Known Member
Just checked my jump measurements to check for erosion and jump was shorter! What causes that? Carbon buildup?
Jump Measurement Shorter?
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General RE LEE
Well-Known Member
Dont understand your last statement. Yes I use 140 and 147 ELDMs and 143 ELDX.
use the same bullet for the measurement same 140, same 147 ect. just put them away for future use. you will never get accurate measurements if using different lot# of bullets, the ogive shape and location always changes every time they set up for a new run of bullets.
If the ogive changes location on a bullet, I dont understand how the distance to lands would change. Its always measureing boltface to ogive meets the lands. Unless you are thinking COAL, then that I can see. Maybe I am missing something
because it is never the same from lot to lot. i have taken 3 different lots and got 3 different measurements, the shape and location are always different. and i have taken the measurements at the same time on new barrels and their different. that is why after my initial measurement i no longer check anymore just drives you crazy. there is only one way the bullet can go as throat wears and that is longer.
I understand how it wears. I don't understand how physically, boltface to lands (measuring ogive) can change with different bullets.
its the difference in the dies and setup every time they make a new run, and you have to factor in wear on the dies. you don't believe me take the same bullets made a year or more apart and check for yourself you will be amazed how different things are.
I have no problem understanding how the bullets, even on the same run can be different. My problem is understanding how for example one .308 ogive touches the lands differently than another .308 ogive. Its the same exact diameter, stops at the lands, stops at the measuing tool you are using. COAL can vary significantly, but I can see how the same diameter can stop at different distances.
I hope the OP gets what he needs from here...
Thanks
believe what you want but I have did this craziness when I first started and seen the differences and that is why I have very little hair left, now don't waste my time anymore. will just say if you are one to be concerned with measurements and comparisons use the same bullet you originally used or your measurements become useless.
That has nothing to do with where the .308 ogive will hit the lands. Only effects the COAL. Its math, physics, geometry, call it what you want...but I am out...not my topic....
years ago when I shot 215 Bergers i seen as much as .020 between lots.
I think what @asd9055 is saying is if you load every projectile to touch the lands on the ogive, the cartridge base to ogive will not change as long as nothing in the chamber has changed. If the ogive is farther back on the bullet the coal will be longer. If the ogive is farther forward the coal will be shorter.
