12-06-2023, 01:42 AM
I figured since I was bored and had plenty of time to fool around loading and shooting I would see if I could lower my powder charge enough to eliminate the ejector swipe. Admittedly it is more of just a light shiny spot. Nothing seems to have been raised by pressure just a light shiny spot. Well I went low enough that the case just about wouldn't eject. Instead of the usual 6 feet out at in between 3 and 4 oclock it just sort of fell out of the gun. This is the minimum load that will function this particular AR. You guessed it still a light shiny spot. It occurs to me that the ejector being spring loaded will be sliding for a short distance across the face of the case as the bolt head turns. This might just be all there is to it. The brass being brand new Starline. At any rate I went the other way using the SMP 763 surplus powder and got really good accuracy until I hit a spot where 3 shots just barely edged over .5. Chrony says 2543 fps average. 120 grain Matchburners. Same exact shiny spot. Wonder if I kept adding powder at .3 grains a three shot group if accuracy would deteriorate around the time pressure gets a bit warm? I just can't come up with a definitive way to tell if I am loading too hot. Brass life? So far I have thrown exactly 3 cases away, all Hornady because primers got too easy to seat. Those cases were on their tenth or so firing. Maybe rounding the edges of the ejector would get rid of the swipe mark?