FWIW,
The ANSI/SAAMI specification for a chamber dimension designates that there is always clearance to the chambered round.
i.e. - the 10 m.m. chamber tolerance for the depth is .922" min to 1.004" max.
Where as the tolerance on the bullet is .922" max length down to as little as .822", so there could be as much slop as .022" or as little as zero.

Then add in the standard tolerance of statistical quality control of a +/- 3 sigma limit ("Bell curve").
Then 99.7% of the parts and chambers will never see the extreme ends of the tolerance limits.

Then add in the clearance specified in the Smith & Wesson pistol armorer's course manual
for the breech face to the barrel chamber hood locking lug to be at .002" - .008" clearance.

The chambered round will not make a firearm that has been made to the proper tolerances, lock up any better.
If it does, then something in those areas was not made to ANSI/SAAMI specification .

Sorry for the rant,
this is a subject that I pay very close attention to in the production of my conversion barrel project.
Regards,
BM1