Is the MechTech Chamber THAT tight ?

[DenStinett]

Found something interesting today:
Finally got around to resizing the Brass for my MG20
I notices it took very little force to get the Case to run up intro the Die
Took an un-resized Case and ran it through my Wilson Chamber Gauge
It almost fit-in and fell-out without any effort....almost as if it were resized ?
Is the Chamber on the MechTech that tight ?
I wonder if the Blowback Design is a factor, in that the Case doesn't remain in the Chamber as long as in most Pistols, and that it doesn't have the time to "Fire Form" to the Chamber
Hmmm ?
Thought ?

[The_Shadow]

The load is lower pressured and well within the design of the brass therefore you are seeing less case expansion.

[DenStinett]

The load is lower pressured and well within the design of the brass therefore you are seeing less case expansion.

Hmmm ?
Basically the same load fired in my Witness Longslide will leave a "bulge" needing to be run through the "Bulge Buster" Die

[The_Shadow]

Have you measured the chamber of both the Witness Longslide vs. the MechTech
What is the load data?

[DenStinett]

Have you measured the chamber of both the Witness Longslide vs. the MechTech
What is the load data?

The MechTech Chamber is:  0.4225" (as best as I can tell without taking the CCU apart
The Witness Longslide's Chamber is: 0.4290" (ugly)
The Wilson Case Gauge is; 0.4220"

[The_Shadow]

It looks like the chamber is tighter on the MechTech...