The action seems "massive" but will still flex under the forces of firing. A tight fit leaves it no where to go. If it has no where to go, the bending forces are going to be transferred to the locking system and that is a very bad thing.

Perhaps some of you have seen the demonstration where a railroad rail is equipped with a strain gage and a short lever to twist said rail. A child usually has no trouble bending the rail enough to make a strain meter register. Force moves metal. The only question is, "How much?"

DDA