But 500 Nitro,

You made No Mention of this procedure (I use a Brass Brush etc), with your Two Bits worth in my posting on "How I clean Barrels".
Did you forget to do this there, or maybe there is another reason???

500 Nitro FYI, they are Bronze Brushes, not Brass!

PS- For everyone's information.
Brushes with Bronze Bristles and a wound Brass Wire core and Threaded section are generally recognized as being the best brushes. Companies like Dewey and some others (?) make these types of bore brushes. These are the types of brushes that the Bench Rest and other accuracy types use.
The other cheaper versions, also have Bronze Bristles but they have a wound aluminum wire core and Threaded section.

Also, don't forget to wash your bore brushes (in Turps or Alcohol), immediately after use with a Chemical bore solvent. If you don't, the solvent will dissolve the Bronze bristles and they break off and end up all through your locking lug recess (bolt actions) and magazine. This could possibly cause other more serious problems, later on!
This also helps to wash out the dissolved jacket fouling and other dirt, so you don't push it back into your barrel!

HooRoo
From
Hommer