Not hearing of Harts is like not hearing of Toyota trucks. Not only being one of the greatest shooting barrels ever made, They also are one of the only companys that stress relieves there barrels when they flute them. An absolutely critical step when fluting a barrel. Not always, but you can absolutely destroy a barrel without stress relieving it with heat when a gunsmith flutes it.
I have a 27 inch sprial fluted Hart on my 7rem mag with a 1-9 twist. I shoot 180 bergers with 65gr of Retumbo. I can put 5 shots in a quarter at 300 yards and i get 4.5 inch groups at 1000.
Again... Harts are one of the finest barrels ever made, along with names like Shilen, Krieger, Lilja and Broughton.
Unless Hart goes under " extremely unlikely in my life time" they will be the only barrels you will ever find on my rifle.