OK, here goes, the drillings are calibrated to mass and speed of projectile.
Try 1 1/8 ounce light loads and see if the pattern moves right
If not on center, try a bit faster load of 1 1/8 ounce.

All this assumes you are a right hand shooter and the chambers are 70mm.

Please report back smile

Mike

p.s. you can also calculate the foot pounds of the rifle load and get in the ball park by
shooting a like foot pound load from the shot barrels, perhaps, possibly, maybe, we shall see ! smile

Last edited by skeettx; 01/11/21 06:39 PM.
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