Resizing Accuracy Issues, .223

[sw282]

Skip the tumbling with ten cases.. l think you are peening/work hardening the brass

 

['Freak]

What's the length measurement from case head to shoulder (~ datum) for the new never fired brass ..?

What's the length measurement from case head to shoulder for that new brass after the one firing but before any “shoulder bump” ..?

What's the length measurement from case head to shoulder after giving that one time fired brass an avg. .004” shoulder bump ..?

 

[Bc'z]

Your post got me to do some investigation. Got a bit of a surprise when I seated a 73 grain Berger OTM and my favorite Lapua 69 g Scenar L.

On the left is the Berger and on the right is the Lapua. Both were seated to touching the lands in a clean barrel. My method leaves nothing to chance, so 100% sure I got an accurate measurement. Notice how the lighter bullet intrudes much more into the case, while the heavier bullet leaves more room for powder. Learned something today, thanks to the OP's post. Bullet on the far left looks like it's not even with seated bullet. That is parallax due to camera position and bullet laying on paper, instead of in a cartridge case.

Secant vs tangent ogive.
The secant having more of a vld design longer nose will seat farther out.
The tangent the ogive is farther forward touching the lands sooner pushing the shank deeper into the case.

 

[Texas10]

Secant vs tangent ogive.
The secant having more of a vld design longer nose will seat farther out.
The tangent the ogive is farther forward touching the lands sooner pushing the shank deeper into the case.

Absolutely true, I could see the difference in the profile quite easily between the 69 L and 73 Berger. Only question is, will it shoot better than the 69 Lapua? I can definitely get more powder in the case, so I have that going for me!