flat bastard file can accomplish! My 03A3 has an 'A' front sight blade which has been shooting around 10" low at 200 yards using a 8" black bull holding a 6 o/clock hold and shooting Sierra 168 HPBT using 48 grs. IMR4895 and F210M primers. I filed the front sight blade down yesterday evening .015" and went back to my range this AM and I'm close to getting it where I want the POI to be. First shot I fired I forgot to move the windage back to mechanical zero and the shot was off to the right at the freshly painted white spot you can see on the AR400 plate below; still a bit low with a good break. I took off about .010" more and shot the 5 rounds you can see in the bull. I'm almost there!
As an aside piece of info, I was talking with one of my LEO buddies that instructs marksmanship for the Ouachita Parish Sheriff's Dept. in Monroe, La. and I was telling him about the accuracy of this 03A3. He listened intently and then said...."Listen Dude...I had occasion to be taken through the Springfield Arsenal on a tour several years ago when I was in that area for a school and I saw things and heard info that I had never been privy to! The tour guide took us upstairs to a large area where much equipment was stored that the general public never gets to see and there was some amazing material in that large room. The guide stressed the amount of 'pains' that were taken just in the building of stocks and the specs. that had to be met and kept before being accepted. Thousands of stocks were dried down and then stored for months at a time and then each was checked for hardness, moisture content, and straightness and if not up to specs....those stocks went into the burn pile!! I'm not at all surprised by the accuracy you're witnessing with that rifle because in the finality....the 03A3 was for all practical purposes more of a target rifle than a combat weapon!"

03A3 Springfield 200 yd. tgt 5 shots by Sharps45 2 7/8, on Flickr

SprgfRegsgt by Sharps45 2 7/8, on Flickr
As an aside piece of info, I was talking with one of my LEO buddies that instructs marksmanship for the Ouachita Parish Sheriff's Dept. in Monroe, La. and I was telling him about the accuracy of this 03A3. He listened intently and then said...."Listen Dude...I had occasion to be taken through the Springfield Arsenal on a tour several years ago when I was in that area for a school and I saw things and heard info that I had never been privy to! The tour guide took us upstairs to a large area where much equipment was stored that the general public never gets to see and there was some amazing material in that large room. The guide stressed the amount of 'pains' that were taken just in the building of stocks and the specs. that had to be met and kept before being accepted. Thousands of stocks were dried down and then stored for months at a time and then each was checked for hardness, moisture content, and straightness and if not up to specs....those stocks went into the burn pile!! I'm not at all surprised by the accuracy you're witnessing with that rifle because in the finality....the 03A3 was for all practical purposes more of a target rifle than a combat weapon!"

03A3 Springfield 200 yd. tgt 5 shots by Sharps45 2 7/8, on Flickr

SprgfRegsgt by Sharps45 2 7/8, on Flickr