Not to be a complete nerd, but I believe you are correct. Given the current specs we know for the OG and OG L (4” reflex for both, .75” barrel channel and 1.55” OD for the OG, and 1” barrel channel with ~1.8” OD for the OG L), the volume of the reflex sections are as follows:
OG: 5.78 cubic inches
OG L: 7.04 cubic inches
The OG L should have roughly 1.26 cu. in. more volume in the reflex section than the OG. If we add in the remaining volume (assuming ovarial lengths aren’t different), we get the following total volumes:
OG: 13.04 cubic inches
OG L: 16.94 cubic inches
So a total difference of 3.9 cubic inches of volume between the two. Again, this is assuming a lot, but just to get a rough idea. Also not sure how significant this is in terms of suppressor volumes - maybe someone else can speak to that.