Brush Guns: Bullet Deflection Through Brush
Russ Chastain 06.29.20
Something many hunters have heard about over the years is the ability (or lack thereof) of a particular cartridge as a “brush round” or “brush buster,” meaning a cartridge whose bullets have an ability to maintain a straight path through sticks & leaves. Conventional wisdom claims that heavier bullets of larger diameter (caliber) are better brush busters. But is that really true?
Paul Harrell decided to take a look at it, and starts out using a 9mm pistol with 115-grain FMJ bullets. Some deflection does occur, but not a lot. He repeats the test with a 45 ACP and 230-grain FMJs and we see little to no evidence of deflection, nor tumbling.
Heading towards the light-and-fast end of the spectrum, he then shoots with an AR and 223 Rem 55-grain FMJ ammo. The group is just fine, but some of the bullets struck the target sideways (or “keyholed”), so the small, light, fast bullets definitely tumble when they hit brush. A repeat of this test through thicker brush shows tumbling as well as significant deflection.
He then moves to a WASR-10 AK in 7.62×39 with 123-grain FMJs. This is certainly not what I think of as a brush round, but it’s definitely larger and slower than the 223 he was using… and it showed no evidence of deflection nor tumbling.
On to what many would call the ultimate brush round: The 45-70. Paul shoots some 405-grain JSPs through the brush, and this is really the first and only one of his tests that uses an actual hunting bullet. Why he chose to use non-hunting FMJ bullets in the other rifles is beyond me.
Disappointingly to folks who believe that slower, heavier bullets can plow through anything and keep going straight, the 45-70 experiences both tumbling and deflection.
Naturally, you shouldn’t shoot through stuff and expect perfect performance out of ANY bullet, no matter the size. That said, I do feel that slower/heavier bullets have less tendency to experience a negative effect from hitting twigs and leaves in flight.
Bottom line for hunters? Wait for a clear shot instead of shooting through brush, no matter what cartridge you use.