300 blackout suppressor question

[Woof]

Been an AK guy all my life and finally got into the AR platform. So I thought I would try setting up a 300 blackout subsonic build.

I have a barrel that is 7.5 inches with a 1:7 twist rate. I have a suppressor that will be out of jail soon, a yankee hill machine r2, I just checked the specs on it, which I shoudl have done before getting the barrel, but it’s minimum barrel length requirement for 300 black out is 8 inches.

Easiest route is to just get a new 8-9 inch barrel. But will having a 7.5 inch barrel be catastrophic to my suppressor?

Building it to run subsonics only (hornady 208gr a max) not supers. Will be a range gun, maybe 500-600 rds to train and practice with, then 1000 rds per year if that. And if it works out it’ll be my new truck gun over the AK platform.

Here are some of the internals if it helps:
Jp enterprise silent capture spring h2 buffer system
Jp enterprise adjustable gas block
SilencerCo gas defeating charging handle

Will running the muzzle brake that comes with the r2 help?
Thanks in advance.

[yellowfin]

Subsonic will be fine. The real erosion is hot supers doing mag dumps.