Originally Posted by DrDeath
What is the mag box fix?


Typically it's a matter of trimming a smidgen off the mag well (box) to relieve any binding that occurs from tightening action screws. If the mag well can not move or rattle after stock screws are tight, then the mag well is putting pressure on the action and can cause erratic groups.

Filing a bit off the mag well box will relieve this pressure.

I was shooting nightmare groups during initial break in/new scope zero......switched scopes with a prove scope, no change. Found this tip on a ruger forum..
.....trimmed maybe 1/32 off the mag well pressure points....started getting MOA results immediately.