Curreny both my daughter and I are shooting my S400 in benchrest comps. As Rosie is only 12 she had our gunsmith cut the stock down by a couple of inches. No I didn't really get much choice in that! I recently managed to aquire a nearly new replacement stock, the rifle is about 9 years old. I have removed the stock before and when replaced it did not affect the zero. When we now change stocks though there is a very consistent 2 moa variation in elevation, with the gun shooting low with the new stock. I have shot the gun with the old shortened stock, and off the bench both of our zero's are the same. Just to make clear the only difference is the stock, I am even using the same stock screw in both stocks. I would not have expected changing the stocks would have changed the zero by that much and so consistently. Dose anyone have any really good ideas why ther should be such a consistent variation between the two stocks?
Slight variation in the inletting of the stock?
He who never made a mistake never learned anything!
He who never missed never shot!
Trouble is, even with differences in the inletting, I don't see why the change of stock should change the zero so consistantly and by som much. I know the S400 is not truly free floated but I can't see the stock affecting the air tube, to then affect the barrel to give a 2moa variation. it would be intersting if it were possible to set the action up on the rest and shoot it without the stock.
Changing the stock shouldn't change the poi at all unless the gun is moving in the stock or its bending breach block when you tighten it up.
So much that that the barrel/scope move, but I cant really see that happening.
Try loosing the bolt ever so slightly, shoot loosen a little more shot, untill it loose in the stock and notice any poi change.
Check the sticky pads at the fore end, near the fill port,
and the scope mounts.
Zero is only the relation to your barrel and scope, a stock is only a way to hold and steady the device. abet some damping of vibrations.
possibly your positioning your eye differently using a different stock.