To follow up. Couldn't borrow the bore scope this weekend. Did another cleaning session on Saturday and ran a few fouling rounds thru the gun. All shots except the very first one went where expected. Didn't feel like I was having a good day behind the trigger so I stopped for the day.
About 2 hours ago walked out to the range with the gun and three different known accurate loads for this barrel. First 5 were 1.18" center to center with the 3rd and 5th shots expanding the group. Next 5, a different loading, did right at .75". Last loading which is the most accurate that I have found so far for this barrel was .58" center to center for all 5 shots which is just about as good as I can do at 100 yds. No more first round fliers! Not sure why but carbon build up in the throat area must have been what was causing my issue. Still pretty sure I don't quite have it all completely out yet, but it's laying them right in there where it always has since I have owned it. Outside of a quick visual inspection of the end of the gas tube and a "feel" inspection of it sliding into the gas key of the BCG, all I did was a fairly deep cleaning of the barrel with great emphasis on the throat area. I still plan on giving it a look with the bore scope hopefully some time this coming week. Edit to add: Thanks to everyone for your thoughts and ideas!
About 2 hours ago walked out to the range with the gun and three different known accurate loads for this barrel. First 5 were 1.18" center to center with the 3rd and 5th shots expanding the group. Next 5, a different loading, did right at .75". Last loading which is the most accurate that I have found so far for this barrel was .58" center to center for all 5 shots which is just about as good as I can do at 100 yds. No more first round fliers! Not sure why but carbon build up in the throat area must have been what was causing my issue. Still pretty sure I don't quite have it all completely out yet, but it's laying them right in there where it always has since I have owned it. Outside of a quick visual inspection of the end of the gas tube and a "feel" inspection of it sliding into the gas key of the BCG, all I did was a fairly deep cleaning of the barrel with great emphasis on the throat area. I still plan on giving it a look with the bore scope hopefully some time this coming week. Edit to add: Thanks to everyone for your thoughts and ideas!