C.O.L. Variability how much

[spersky]

Measuring with calipers. I am getting C.O.L. from 2.81 to 2.82. My redding seating die never moved. Using Lapua Brass and Scenar 155's

Is that how inaccurate the bullet lengths are?

I guess I need to start measuring Ogive.

 

[Bacarrat]

Re: C.O.L. Variability how much

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: spersky</div><div class="ubbcode-body">

I guess I need to start measuring Ogive. </div></div>

This.

 

[JSTARSZ]

Re: C.O.L. Variability how much

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bacarrat</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: spersky</div><div class="ubbcode-body">

I guess I need to start measuring Ogive. </div></div>

This.</div></div>
+2 - you need to measure from the ogive. I used to do as you did and I would be close but once I found out about the ogive and got a new tool it all came together. You are probably more consistent then you think but you were measuring an area, at the tip, that is not consistent.

 

[Fuzzball]

Re: C.O.L. Variability how much

"I guess I need to start measuring Ogive."

Yep. No rifle cares where the point of bullets hang in the air.

 

[Victor N TN]

Re: C.O.L. Variability how much

In the manufacture of bullet jackets the length varies several thousandths on the length. That extra length of the jacket shows up on the nose / point of the bullet. Your bullet seater die is seating by touching back on the curve or ogive of the bullet. This lets the end of the bullet vary slightly without affecting the placement of the actual ogive as much.