Im calling it good for hunting. Will run a 10 shot group next Saturday just to verify.
The .243 shot best group at .44 at -040 off the lands
I cut the melamine sheet in half my total top size is 47.25 inches square the tail is about 19 inches square I made mine 3.5 inches deep. Takes six 80lb bags of premixed concrete.
Thanks for the thoughts all around guys, will check all of this again tonight and see what the story is.
If it was extending beyond the bushing, then it should be flared before I put the mandrel down it, but its not, so I suspect that isn't the issue. The fact there might be a ridge on the inside of the neck like Fuj mentions is certainly possible though.
Fuj - right now I neck, mandrel, inside/outside chamfor. (This is assuming they don't need a trim, which is almost always). Do you chamfor before running a mandrel in? I wouldn't expect them to have a ridge on the inside of the neck but i'll pull a dental pick over a couple tonight and see if i can feel something.
As Jerry mentioned in his previous post, attempting to assess the effect of primer seating on group size, particularly at 100 yds where most load development is done, is not going to be very fruitful. Any change is going to be so small that it will be masked by other variables. However, the effect on ES is readily obtainable with any decent chronograph. So if you're developing loads with the goal of having consistent POI at long range (1000+ yards), assessing any variable that might reduce ES would seem reasonable and not all that OCD.