I had a great weekend camping and shooting my .223. I started with a near perfectly clean bore and saw the gun was shootin about a half inch to the left, so I gave the scope a few clicks to the right and the gun was driving tacks all weekend long out to about 200 yards.
At the end of the trip someone was using my gun for a few shots and they were missing a small plate at 180 yards and I took a few shots to see if it was the gun. Sure enough, it was missing. I had to aim a few inches higher and the gun was then hitting with regularity again.
So, it appears that after about 175 rounds, the point of impact dropped maybe 1.5 to 2" at about 200 yards from when I started with a clean bore. These little things confuse me and I try to understand why they happen. So, could I have simply misjudged things or could the POI have actually became lower after 175 rounds going down the tube without a cleaning? Either that or the scope shifted which I wouldn't have expected.