The Hoppe's brushes I pick up at Wally World are for .30 to .32 caliber. They will do 2 to 3 aggressive cleanings on my 93 Turks, Then a couple on the .30 cals, then they are good only for patch holders. Using Romy corrosive requires a brush to get the **** out. I use a soapy swab at the range when done shooting, but it won't budge the ****. I don't use Hoppes #9, but am trying to get the new #9 as it's designed for corrosive ammo.