In addition to threading your Mini-30 barrel to accept the M14 flash suppressor, you’ll have to figure out a way to deal with the splines (I think that’s the right term) on the inside of the M14 suppressor. The splines are there to line up the suppressor correctly. The M14 barrel is grooved to accept the splines, and it would be tough to create the grooves on your Mini-30 unless you’re a machinist with access to the right equipment. I think the best thing to do would be to remove the splines from the M14 flash hider.
I’ve thought about doing this on my Mini-14 and even bought a M14 FH for the project but I decided to go the Vortex route. Let us know how you make out with this.
P.S. If you’ve got a post-ban Mini-30, make sure you “neuter” the M14 flash suppressor (i.e., remove that deadly bayonet lug).