Tikka 1:8 243 - 108 eldm seating depth

[satchamo]

This is a ridiculously specific question so not sure anyone will have the answers I seek but here goes…

I’ve been trying to find the lands using a Hornady OAL tool and a modified case and it seems like I’m getting all sorts of varying measurements. I’m struggling to get a feel where to stop.

I’ve gotten anywhere from 2.17 to 2.26. I covered the bullet in sharpie and I’m not seeing land marks but yet I managed to jam a bullet in there and had to use a cleaning rod to get it out.

Does anyone with the same rifle/bullet have their cartridge base to ogive measurement with the same setup? I know there will be variance from gun to gun but just trying to get a sense of whether I’m close on one end or the other…

Any other tips or tricks are appreciated!

 

[swavescatter]

Try to use the same light pressure each time to get the bullet to *just* contact. Let go of the plastic push rod before tightening. I've seen where people get measurements all over the place by tightening the screw with pressure on the rod.

If all that fails, you can try the loctite trick.

 

[dirtytough]

I pull my bolt apart and remove the ejector and firing pin. After they are gone the bolt will close on it's own when the bullet isn't touching the lands.

With Mitutoyo calipers and Hornady comparator.

108 ELD 2.276"
103 ELD 2.278"
105 HPBT 2.262"
112 MB 2.270"
109 LRHT 2.272"

 

[Harvey_NW]

I didn't really care for the Hornady gauge and buying all the extra modified cases. For just finding the lands and tracking throat erosion I've found this to be pretty handy and mostly repeatable, +/- a few thou. I just hand seat a bullet in the neck of a sized case as straight as possible, and push it in the chamber with my finger, then push it back back and forth with the cleaning rod a couple times to make sure it feels like it's straight in the throat and the "touch" is consistent before setting the second stop.