Dear Mr. Rodrigues,
Attached picture shows you the two synthetic inlays in the fore end.
Next to the stock you see them as spare parts.
When disassembling the fore end the user always has to make sure that he does not loose these inlays, otherwise accuracy will be lost.
With these inlays we really can claim to have the best shooting Stutzen in the world. Your experience with this rifle shows that we are right.
When taking off the fore end and putting it on again (with inlays) nothing will happen to accuracy because you still have the same barrel in the gun.
But when now changing the barrel it can happen that the length of the stock leads to the problem that the hole of the metal cap is not 100 % in position for the hole in the new barrel.
When then assembling the metal cap and fixing the screw at the muzzle you can get tension on the barrel which will finally leads to bad accuracy.
Therefore we tell the market that there is no barrel interchange ability at the Stutzen because the user cannot change the hole in the cap or adjust length of the stock perfectly.
Here in the factory we just take a new fore end with perfect length that the hole of the cap fits exactly to the hole of the new barrel. Therefore we can change barrels but it might happen that we need a new fore end. So it is almost impossible to have one Stutzen with one fore end but two or more barrels because you cannot manufacture wood to this precise tolerance.
I hope this answers your questions.
Best regards
Matthias Klotz
Product Manager SAUER
J.P. Sauer & Sohn GmbH
Sauerstraße 2-6
24340 Eckernförde
www.sigsauer.de