I slipped a piece of roll pin onto the front sight post, fired a couple of rounds, filed the roll pin down, then fired another couple of rounds and filed again...finally the POI was brought to the bull's eye. Yesterday I was able to put 3 shots into 1 1/2 inch group at 100 meters with iron sight with my handloads.
But...I've found something strange. I was shooting 174 gr hornady interbond roundnose and 174 gr hornady fmj boattail. The roundnose is .312, and the fmj is .3105. I was expecting the roundnose to drop more at 100 meters with both being pushed by 44 gr of IMR4895. But to the contrary the fmjs were 2 or 3 inches lower than roundnose! So I'm assuming that my gun's bore is bigger than .311.