This is actually regarding my new Kimber .45 but I would imagine cleaning theory should be the same, so....
Got a new .45 and decided to clean it to "aquaint myself with it" before I hit the range. Bought a Tetra Gun Care brass brush for ".40/.45" caliber, and a Tetra bore mop. The bore mop fits nice and snug through the barrel and cleans nicely, but the brass brush barely touches the sides. Like a "hot dog down a hallway" as the saying goes... Both of my cleaning brushes for my AR and my AK give some resistance through the barrel. Is this brush mis-labeled or am I perhaps doing something wrong?

Definitely doesn't sound right.  The brush should be a tight fit in the bore.

I honestly don't see how you could do it wrong.  Unless your gun is reall a .50

I'd say your using a 40 cal brush in a 45 cal bore.  Only time I do that is when I have a 45 cal patch wrapped around the brush.

Your packadge ismisinforming you. 40 cal can not work in 45 cal.

ps you know there is a HANGUN section.

yeah, i know there's a handgun section, but it has ONE active question so I figured the odds of getting a quick response would be just a weee bit higher here....

anyway, I also thought it was odd that it claimed to be for .40 AND .45...
I'll look for a different brand brush with a little more specific caliber marking.

thanks.

update:  Bought a Hoppes Brush Kit and it is the perfect size. I don't believe that I will be buying Tetra junk anymore.

tetra packadge I see reads for 40-41 and another brush 44-45 cal.  I think you bought the wrong brush size.

i just double checked the package and it does say ".44/.45" but it must be the .40 in the wrong packaging or something.