Measuring concentricity

[dantiff2]

where do you all put the point of the indicator to measure run out?? I place on the middle of the neck and got next to nothing, 1/2 a thou .0005 but when I move to around the ogive of the bullet I get a .003 to .0035 TIR...

thanks

Dan

 

[TiGuy]

Sounds about right. Try to determine how to get acceptable runout at the ogive too. A "perfect" bullet seating should give you same runout as the case neck measurement you are getting,.01).

 

[fdshuster]

dantiff2: I have and use both the RCBS and the Sinclair, frequently checking one against the other. Readings on a particular cartridge will be the same. Anyway, I prefer to have the dial indicator "point" contact the bullet ogive at the same location where the ogive contacts the lands/leade. The further out toward the tip of the bullet, the more runout you are likely to have. .002" is my maximum: more than that & it's kept for 100 yd., basic scope sight-in, first round bore fouling, etc. Check some factory ammo sometime. You will be shocked how much you may find. I did, and some so-called match ammo had as much as .012".