Aj from United States, CT Public Profile

I had a Springfield Gen 4 aluminum mount on a new M1A with Leupold MK5 HD scope. Grouping was horrible. Sent rifle back to Springfield with scope still mounted. Springfield replaced the barrel and said everything is good but range time says otherwise. Flustrated I replaced mount with Sadlak mount. Instant improvement.
WHY?
There is a threaded hole for a scop mount with three alignment groves built into the side of the rifle. The instructions for the aluminum Springfield mount has you hammer their mount into the groves while tightening their screw. This procedure is intended to press fit/deform the aluminum to sit securely into the groves. Unfortunately, this deforming procedure will not allow the mount to bottom out into the groves (so the mount can't make full face contact with the surface face of the rifle.) As such, the mount teeters on these alignment grooves and your scope mount can tip in (top front end of mount can move to the right causing shots to go low right).

With the Sadlak mount, the vertical grove is only used to obtain the solid, flat, face mount. This allows the horizontal groves to provide alignment without tipping. As an added feature, if any tipping should occur, is prevented by their setscrew on the top forward end of the mount.