Another possibility is that the bore needs to be lapped. I have a Dutch model and found the same accuracy issues. I finally decided to drop a gauge pin down the barrel and found a tight spot 4" down (this was after removing the last .5" of barrel because of its condition.

I still haven't gotten around to lapping but that should solve the problem.

Please follow xausa's advice regarding the bullet fit in a fired case. A tight fit in the neck of a loaded cartridge can be dangerous.

Tom