The screws go in at a shallow angle, have points on the end, and contact the left barrel about 45 deg from center horizontal of the bore line. Unfortunately, the regulation needs the barrels tighter together at the muzzle at the max speed of my 350 gr(2250 fps) with the screws out. Trying to remove maybe another .005" from the left side of the muzzle block now. Or I can rechamber to 45-120, for more speed. The left barrel is not soldered forward of the sling attachment block. The screws move the impact about 4" per 1/4 turn, so it's pretty sensitive. Right now the left is 4" away to the left, from the right at 50 yds.