When I was pursuing the internet mythical 1" 5 shot group at 100 yards in the 1990's, everyone said they could do it, but for years I never saw anyone do it.
Then at two different ranges on in 1999 and one in 2001, I saw a 1" group.
The first was a Win 70 Coyote .223 shooting Federal Gold match with benchrest shooting rest and rabbit eared rear bag. The guy was at the range every day.
The second was a 91/30 with ancient Fajen stock, home made scope mount, 18X Redfield that was dim, the muzzle was cut off 1/2" and re crowned. The barrel had been hand lapped with a lead lapp, Clover valve grinding compound, and home made bore guide. The bore was frequently cleaned with Outer's foul out to get more rust out. The load was a hot load of Sierra 180 gr and IMR4350.
The bore looked like a sewer pipe.
I felt like I was being played with. I felt tricked somehow. How could that rotten sewer pipe shoot that well?
Now I have an M39 I have scoped and welded the bolt handle. It will shoot that well.
I am using 180 gr Sierra bullets and Lapua brass.