07-17-2011, 04:51 PM
LRRPF52 Wrote:I just got returned from a 2-day course I ran, and...we encountered several situations where pretty dense vegetation was partially-obstructing most of the targets on the patrol lanes (by design). We were wondering how these obstacles in the path of 5.56 might affect shot placement, so I had one of the guys get down and purposely shoot through tall grass and weeds that were between him and the target. POA-POI was on, with no signs of key-holing that we could detect on targets from 24m out to about 60m. Everyone had 10-16" barrels on the AR's, wit most being 11.5" or 14.5". I didn't notice any key-holes throughout the two days of high-volume shooting on any of the targets, and every target in the patrol lanes had vegetation partially-obstructing it.I'd say it depends upon the vegetation. Grass and weeds may not offer sufficient resistance to cause bullet deflection.
Years ago I ran a test to check on the reported claims that bigger bullets fared better in brush busting. I stuck a 3/4" dowel into the ground, with a target several feet behind it. I fired three shots each of FMJ ammo in .45 ACP, 9x19, 7.62x51, and 5.56x45. To my surprise, .45 deflected more than 9mm, and 7.62 more than 5.56, with all rounds showing severe keyholing.
The only trouble with said testing is that all of the .45, 9mm and 7.62mm bullets grazed the side of the dowel, whereas all of the 5.56mm bullets punched through the dowel. I tried several more shots with 5.56, but was unable to achieve any grazing hits, which IMO renders the 5.56 portion somewhat inconclusive.