Gun that surprised me? Winchester Model 1917 dated 1918 w/ original barrel ... bore was sewer pipe quality. It sprayed any 150 gr. loads I tried. Back then I normally expected about 1.7 inch groups from my 2-21 dated 1903 Springfield. However, one day I whomped up some handloads for the Winchester... 180 gr. RN Hornady's over some now forgotten powder charge. Viola! That old warhorse started producing nice, round five shot groups that ran about 1.5 inches... nicely centered! Who'd have thought it!
Another one... a Korean era M-1 Garand that had a loose gas cylinder, a loose stock fit and a worn barrel. I did a bit of fidlding w/ the gas cylinder so that it ended up fitting "snug." I shimmed the receiver in the stock w/ some business cards cut to fit. I loaded it up w/ PMC 150 gr. soft-point ammo. It went from minute of can accuracy at 100 yds. to producing right at 2.0 inch five shot groups. Later that year I used it to kill a nice doe. She was standing over on the other side of a open bit of water down in the woods. I was standing on the other side. I compared her to the other two does using the front sight to figure which one was the largest ... then I shot her headon in the chest. She dropped like a stone. Distance was a little over a football field. Ended up having to leave my rifle and gear while I swam over and got her as the water turned out to be deeper than I first thought.
Got a Springfield 1903... high number made about 1918. Had been through a arsenal rebuild (RA-P) where it got a new Sedley 1944 barrel, a scant stock and mixed milled/stamped parts. All in all, a nice rifle. Unfortunately, the bore was... "tarnished." Cleaned it with everything known to man... no better. Took it to the range not expecting much. Had a sack of 95 rounds of .30-06 hunting ammo... Federal, Winchester, Remington, given to me by a church member. I had sorted the ammo out the night before. Shot carefully from sandbags off the top of my car firing at a SR-1 at 100 yds. Using the apeature rear sight... that thing shot like a death ray. Best group of the day was a perfect one inch five shot group using Winchester Silver Tips. Fired all 95 rounds over about 2 1/2 hours. All groups were under 2 inches.
Last one... Remington 1903 that came through the CMP. The stock looked rough. The exterior metal looked excellent. The barrel... a High Standard 1944 replacement... bore was mirror bright. After cleaning and degreasing the stock, etc., put it back together. Had to shim the rear sight as it was a bit loose. Result is it is now my vintage military match rifle. Because of the stock... I call it "Crackbaby!" Sincerely. brucev.