COL versus ogive - how much variation?

[DJL2]

Edited to update - crappy memory, had to get the calipers out again.

I was measuring COL on some ammo and noticed BIG deviations. Like 15 (not 30) thou. This was with 195 TMK. I was seating around 3.34 - 3.33 (doing a seating depth test) and noted about 1/3 of the projectiles I loaded came out around 3.315-3.325. This was a small sample trying to find tune seating depth.

I was curious and grabbed 10 rds of 6.5 CM loaded with 130 TMK...1 of 10 was, again, about 15 (not 30) thou long (not short).

I've color coded the odd balls with Sharpie on the neck...curious to see where they go.

The 195 TMK I just measured were all between 1.484 and 1.487 in length.

That doesn't seem right to me and I'm trying to figure out what's what. 6.5 CM was a Whidden die, the -06 was a Redding die.

Background - I seem to really suck at hand loading, really looking for gross error on my part.

 

[Steel head]

tips can vary a lot even on quality bullets.
Measuring the ogive to base is a better way to get consistent measurements and not chase your tail from tip variations.

 

[DJL2]

Well, when your Dumas loads a bunch of ammo that doesn’t fit in your magazine because you were single loading and thought it fit...

It’s amazing how short the internal box is on my M70.

 

[Joel Danielson]

tips can vary a lot even on quality bullets.
Measuring the ogive to base is a better way to get consistent measurements and not chase your tail from tip variations.

In addition to the above, if you have varying seating pressure, it will change seating depth.
Cheers