All,
In order to fine-tune my headspacing on my .223 reloads I invested in a RCBS precision mic:
http://www.midwayusa.com/product/477756/rcbs-precision-mic-223-remington
To set up a control environment, I checked 20 factory-loaded Remington .223 rounds.. all perfect zero in the device. I fired 10x in two different (and relatively new) uppers (carefully keeping the fired brass separate to know which is which), took them home and measured them. Both sets had their headspace stretched by .001 from factory. So far so good, that makes sense.
When I set up my Dillon carbide .223 FL resizing die into my D550B and sized the brass there was no change in the headspace.. even after screwing the damn die all the way down to where it makes contact with the shellplate. I marked up the neck on piece of brass and sized it, I could not see that the resizing die is hitting the shoulder of the casing... just the neck. This is a full-length die, not a neck only.
To re-test this, I found some fired brass that had been used in a friends upper. It measured +.005" in the RCBS mic. I sized it in the screwed-all-the-way-down resizing die then re-measured it. No change in the headspace.. It still measured +.005" in the RCBS mic.
Am I doing something wrong here? I was under the impression that the headspace can be bumped down by screwing the die down slightly. If this is the chase is it possible that my die is not to tight enough tolerance?
In order to fine-tune my headspacing on my .223 reloads I invested in a RCBS precision mic:
http://www.midwayusa.com/product/477756/rcbs-precision-mic-223-remington
To set up a control environment, I checked 20 factory-loaded Remington .223 rounds.. all perfect zero in the device. I fired 10x in two different (and relatively new) uppers (carefully keeping the fired brass separate to know which is which), took them home and measured them. Both sets had their headspace stretched by .001 from factory. So far so good, that makes sense.
When I set up my Dillon carbide .223 FL resizing die into my D550B and sized the brass there was no change in the headspace.. even after screwing the damn die all the way down to where it makes contact with the shellplate. I marked up the neck on piece of brass and sized it, I could not see that the resizing die is hitting the shoulder of the casing... just the neck. This is a full-length die, not a neck only.
To re-test this, I found some fired brass that had been used in a friends upper. It measured +.005" in the RCBS mic. I sized it in the screwed-all-the-way-down resizing die then re-measured it. No change in the headspace.. It still measured +.005" in the RCBS mic.
Am I doing something wrong here? I was under the impression that the headspace can be bumped down by screwing the die down slightly. If this is the chase is it possible that my die is not to tight enough tolerance?
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