TC Scout breech plug vents

[whittler]

Can anyone explain what the is need for the vented breech plug on the TC Scout? The explaination from TC is it makes more consistent pressures and better accuracy, I just can not see how that is.
Has anyone ever made a standard breech plug with only the nipple for a Scout, and if so how did it work out?

[tc scout]

I had one for years. I think the only reason Thompson put those vents in were to prevent hammer blow back. As far as I know there was never any other nipples available for them. They really were not breech plugs, just over sized  nipples.
One thing they were good for was blowing crap all inside the receiver