I've been trying to get an accurate measurement for the lands on my Barlitien barrel (AR15 upper), so I started with taking a fired case, bumping the shoulder back .003 and busing sizing the neck ever so slightly to hold a bullet enough to be pushed in with moderate pressure, but still hold relatively firm.
After 8 attempts or so cambering and making sure the bolt goes into battery, then using a cleaning rod to help push the case out (making sure the bullet is not jammed in the lands) I got 4 readings that were 1.711 - case head to ogive on a 123 ELD.
Doing the same with a Hornady OAL gauge, I get 1.681. That is a huge difference. I would have expected the fired case to be shorter, not longer, but that is going off the bolt rather than the case being shoved all the way into the freebore.
I measured some Horandy American Gunner and it measures 1.695 (ELD is 1.660). When I chamber the HAG ammo, it does not jam in the lands, and the measurement does not change, no marking on the bullet. According to the Hornady tool that should be jamming into the lands.
Where am I screwing up that I can not verify my measurement with the tool vs the DIY fired case? I am trying to figure out what my jump to lands should be since when I am loading ELD to mag length (2.266 +/-.002) 1.696 to ogive ~ .005 off the lands based on my DIY fired case. This might explain the pressure signs on reloaded ammo significantly below what others are using as safe.
After 8 attempts or so cambering and making sure the bolt goes into battery, then using a cleaning rod to help push the case out (making sure the bullet is not jammed in the lands) I got 4 readings that were 1.711 - case head to ogive on a 123 ELD.
Doing the same with a Hornady OAL gauge, I get 1.681. That is a huge difference. I would have expected the fired case to be shorter, not longer, but that is going off the bolt rather than the case being shoved all the way into the freebore.
I measured some Horandy American Gunner and it measures 1.695 (ELD is 1.660). When I chamber the HAG ammo, it does not jam in the lands, and the measurement does not change, no marking on the bullet. According to the Hornady tool that should be jamming into the lands.
Where am I screwing up that I can not verify my measurement with the tool vs the DIY fired case? I am trying to figure out what my jump to lands should be since when I am loading ELD to mag length (2.266 +/-.002) 1.696 to ogive ~ .005 off the lands based on my DIY fired case. This might explain the pressure signs on reloaded ammo significantly below what others are using as safe.
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