5-Pack .40 Caliber Brass Bore Brush

In stock
SKU: BR-0001-040-p5

The .40 S&W and 10mm share the same bore diameter - so this .40 caliber brass bore brush cleans both. Phosphor bronze bristles cut through carbon deposits and lead fouling that build up from high-pressure pistol loads, all without scratching your barrel. The bristles wear down over time; your bore doesn't.

The .40 caliber sits in a unique spot among handgun rounds - more energy than 9mm, less recoil than .45 ACP. It's a favorite with law enforcement and competition shooters who value that balance. Whether you run .40 S&W for duty or 10mm for woods carry, the hotter loads in this caliber group produce heavier carbon fouling than lighter pistol rounds. Regular bore cleaning prevents buildup from affecting accuracy and function.

Solvent, this pistol cleaning brush, a few passes - that's your gun cleaning routine for .40 cal. Use the right size brush for the bore and you'll feel the difference: proper bristle contact means less effort and a cleaner barrel every time.


Caliber:
10mm Auto, .40 S&W
Product Type:
Bore Brush
Firearm Type:
Pistol
Use Case:
Bore Fouling Removal
Bristle Material:
Phosphor Bronze
Core/Stem Material:
Twisted Wire (Brass)
Bore Diameter (in):
0.4
Thread Size:
8-32
Pack Size:
10-Pack, 20-Pack, 3-Pack, 5-Pack, Single
Country of Origin:
Imported (China)
Brand:
GUNNIX
Is .40 S&W the same as 10mm for cleaning purposes?
Yes. Both cartridges use bullets with a diameter of 0.400 inches and share the same bore diameter. A bore brush labeled ".40 caliber / 10mm" fits both. The difference between the two is in case length and powder charge - the 10mm is a longer, more powerful cartridge - but the barrel bore is identical, so one brush cleans both.
What size bore brush do I need for .40 cal or 10mm?
Use a .40 caliber / 10mm bore brush with 8-32 threads. This is the standard thread for pistol cleaning rods. The brush diameter is specifically sized for the .400-inch bore. Don't substitute a .38/9mm brush - it will be too small and slide through without contacting the bore walls properly.
Can I run a bore brush back and forth through a pistol barrel?
Yes. A phosphor bronze brush is safe in both directions. For pistol barrels, which are shorter than rifle barrels, most shooters push the brush through from the breech, let it exit the muzzle, then pull it back. A few back-and-forth strokes with solvent loosen carbon and lead. The brush wears down gradually with use - replace it when the bristles no longer feel snug in the bore.
What is the best bore brush material for .40 caliber?
Bronze handles the carbon and lead fouling typical in .40 S&W and 10mm. If you shoot jacketed hollow points, copper fouling joins the mix, and bronze bristles loosen it for solvent to dissolve. Nylon is gentler and works for light maintenance, but when your groups start opening up and you suspect bore fouling, bronze is the tool that fixes it.
What is the best way to finish cleaning after brushing a .40 cal bore?
For pistols, either works well given the short barrel length. A jag with patches gives you a clear read on bore condition - you can see carbon and copper residue on the patch. A bore mop absorbs more solvent and finishes faster. The practical approach: brush with solvent, then a jag with a wet patch, then a dry patch. If the dry patch comes out clean, you're done.