OK. In the quest of reducing velocity dispersion. (I'll get to the OCW effort a bit later)
No way to get "new" cases, so for Group 1, I gathered 5 "once fired" .308's Remington that I had on hand for another gun. FL size, trim, bevel, neck size, prime, 41.2 gr Varget from Chargemaster, seat bullet. Note I generally always neck down .308's for 7mm08 so I end up with a tighter fit in the neck region in my sporter barrel.
Group 2: 5 previously fired cases: necksize, no trim, prime, 41.2 gr Varget from Chargemaster, seat bullet (these felt much less neck tension)
Group 3: 5 previously fired cases: FL size, prime, trim, bevel, no neck size, 41.2 gr Varget from Chargemaster, seat bullet.
Gave up on heading 29 miles to the range this late (spent most of day working on an engine), may be able to anneal some cases tonight, create another test group, head to range tomorrow. If I do, I will run them into the FL sizer only ONCE.
Discoveries so far:
1. My Lee bullet seater was seating much less precisely than I had remembered. These are light-for-caliber 120 grain Sierra spire points. The cases group in group three (tighter neck tension) tended to have too-long COAL by .005 or more ; the cases from group two (much looser neck by my "feel" of the press) tended to have too-short COAL (by roughly .004) ....this was unexpected. And, since I'm near "lands" -- this might be very significant. [In 6PPC, my Lee did just about as good as a Wilson! so this is a useful discovery for me. Perhaps I need a better or custom seater......] I readjusted the worst outliers....by COAL.
2. I have a simple Hornady comparator set, may check that on them, if so, perhaps adjust for similar comparator readings?
3. Note that I switched to the Chargemaster to avoid issues of powder variabilities.
No way to get "new" cases, so for Group 1, I gathered 5 "once fired" .308's Remington that I had on hand for another gun. FL size, trim, bevel, neck size, prime, 41.2 gr Varget from Chargemaster, seat bullet. Note I generally always neck down .308's for 7mm08 so I end up with a tighter fit in the neck region in my sporter barrel.
Group 2: 5 previously fired cases: necksize, no trim, prime, 41.2 gr Varget from Chargemaster, seat bullet (these felt much less neck tension)
Group 3: 5 previously fired cases: FL size, prime, trim, bevel, no neck size, 41.2 gr Varget from Chargemaster, seat bullet.
Gave up on heading 29 miles to the range this late (spent most of day working on an engine), may be able to anneal some cases tonight, create another test group, head to range tomorrow. If I do, I will run them into the FL sizer only ONCE.
Discoveries so far:
1. My Lee bullet seater was seating much less precisely than I had remembered. These are light-for-caliber 120 grain Sierra spire points. The cases group in group three (tighter neck tension) tended to have too-long COAL by .005 or more ; the cases from group two (much looser neck by my "feel" of the press) tended to have too-short COAL (by roughly .004) ....this was unexpected. And, since I'm near "lands" -- this might be very significant. [In 6PPC, my Lee did just about as good as a Wilson! so this is a useful discovery for me. Perhaps I need a better or custom seater......] I readjusted the worst outliers....by COAL.
2. I have a simple Hornady comparator set, may check that on them, if so, perhaps adjust for similar comparator readings?
3. Note that I switched to the Chargemaster to avoid issues of powder variabilities.