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Shooting through vegetation (sort of): An experiment with 308 Winchester ammunition. Login/Join 
Freethinker
Picture of sigfreund
posted
Back in the pre-Internet days when shooting-related mass media consisted almost entirely of articles in magazines and other periodicals, much attention was focused on hunting. A frequent topic was the issue of shooting through vegetation. Although there were some ideas about “brush busting” cartridges and loads, it was generally discouraged. In more recent times, what discussion I have seen among current long range shooters has condemned it even more, to the point of claiming that any contact with vegetation is an accuracy killer.

With all that in mind, I have been thinking for some time of an experiment to determine just how bad accuracy is affected if the bullet hits something like a twig, or perhaps even leaves or grass. Today I finally made it to the range.

The rifle was a Tikka T3x TAC A1 chambered for 308 Winchester. The three ammunition loads were Federal 175 grain Gold Medal Match with Sierra MatchKing bullet, Federal 168 grain Gold Medal Match with Sierra MatchKing bullet, and Hornady 155 grain A-MAX TAP. The first is still used as a military sniper load; the second was used by the military for a time, and is still a common law enforcement sniper load; the third is a load highly recommended by some LE sniping authorities. The first two are considered to be nonexpanding open tip match bullets and the TAP is a higher velocity load due to its lighter bullet that expands rapidly in flesh and transfers its energy very rapidly. The TAP is a very precise load that also penetrates less than the match bullets.

The test consisted of setting up a screen of bamboo cooking skewers about 0.12 inch in diameter between the shooting position and the targets that consisted of brown 0.9 inch square target repair stickers.

I will discuss some of the weaknesses of the test protocol at the bottom of the post, but first the conduct and results. The skewer screen was set 22 yards from the firing position and the targets at 55 yards. The first shot of each string was fired at the aiming point without the screen in place.

The first load fired was the 175 grain Gold Medal Match. The first shot through the screen grazed one skewer and left a black mark (see the photo). That grazing shot touched the first unobstructed hole. The third shot hit a skewer directly enough to badly damage it. That shot hit slightly above and to the right of the first shot.

The second load fired was the 168 grain Gold Medal Match. The one shot through the screen hit a skewer directly enough to cut it in two.

The third load fired was the Hornady 155 grain A-MAX TAP. The one shot through the screen hit a skewer directly enough to cut it in two. There are three holes made by this load pictured because I decided to fire a last shot without the screen in place to compare it to the previous two.

Based on my prior research, I expected the skewers to have a much greater effect on the accuracy of the three loads, especially the expanding A-MAX bullet. I was initially hesitant to place the target at 55 yards because I thought a deflected, tumbling bullet might miss the paper entirely.

As is obvious, even hitting a skewer directly had little effect on the accuracy, and no apparent effect on bullet stability. Because the brown squares were so large, some of the deviation among the shots may have been due to aiming errors. In any event, the massive deviation and possible tumbling did not occur as I anticipated. Was there enough deviation to affect a long range shot? Probably, but my experiment didn’t establish that. If I try a repeat with more difficult obstacles, I may try bamboo chopsticks. Why bamboo? It is tougher and less brittle than something like an ordinary dowel, and I believe may be a little better simulant for living vegetation.

Although the results of my experiment were hardly startling, they may be of some interest.

The rifle.




The setup.




The screen.




Hits on skewers by Federal 175 grain Gold Medal Match bullets. Grazing hit is circled (skewer was rotated to show the contact mark.)




Holes in 55 yard target from 175 gn. GMM. Hole marked in red was the first, unobstructed shot. The hole closest to it was made by the shot that grazed the skewer. The third hole was made by the shot that hit the skewer more directly.




Hit on skewer by Federal 168 grain Gold Medal Match bullet.




Holes in 55 yard target from 168 gn. GMM. Hole marked in red was the first, unobstructed shot.




Hit on skewer by Hornady 155 grain A-MAX TAP bullet.




Holes in 55 yard target from 155 gn. TAP. Hole marked in red was the first, unobstructed shot. The hole with the small black mark at the top was the shot that hit the skewer. The unmarked hole was a final shot that was not obstructed.




As I mentioned, I expected the thin cooking skewers to have more effect on the bullets that hit them. Thicker obstacles should be used if there’s a next time. The samples were of course very small, but I should have fired final unobstructed shots for the first two loads to provide a better baseline. More important, my aiming aids were much too large; something like a Sharpie dot at 15× and 50 yards would have resulted in more precise results.

There is a trend these days toward smaller caliber cartridges in 6.5 and even 6mm for long range shooting, but I chose the 308 Winchester for the experiment because I expected the accuracy to be affected much more. Even now, though, I’m pretty sure if I hit a skewer with a 0.224 caliber varmint bullet that the results would be much different.




7/93
 
Posts: 45893 | Location: 10,150 Feet Above Sea Level in Colorado | Registered: April 04, 2002Reply With QuoteReport This Post
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55 yards is so close, I'd expect little difference in accuracy as your test pointed out. But I wonder how much that little difference would be at 100 yards or even further?
 
Posts: 867 | Location: WV | Registered: May 30, 2013Reply With QuoteReport This Post
Freethinker
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I'll have to find some (more) bamboo chopsticks, and next time set the target at 100 yards.




7/93
 
Posts: 45893 | Location: 10,150 Feet Above Sea Level in Colorado | Registered: April 04, 2002Reply With QuoteReport This Post
goodheart
Picture of sjtill
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I'd be interested in the effect on accuracy of serial obstructions, more like what one might expect shooting "in the woods".


_________________________
“Now, I’ve said this before, and I mean it. I believe love is the answer. I do. But I also own a handgun, just in case.” - Sen. John Kennedy, LA
 
Posts: 17131 | Location: One hop from Paradise | Registered: July 27, 2004Reply With QuoteReport This Post
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This is something I have been wondering about recently as well, and tested, to a degree, a few weeks ago. A friend and I inflated a balloon to about 6-8", and attached it to a tree. We then walked away from it, for a distance of over 100m. We turned back toward it, and walked until one of us spotted it, through the trees. My friend spotted it at a distance of 75-100 meters. He could only see it if he stood exactly where he was, when he initially spotted it. He tried to prop on a nearby tree, or shoot from a kneeling position, but lost his view of the target in doing so. I thought his round would be derailed for sure, but he hit the dang thing. This was with 5.56.
 
Posts: 1128 | Location: Northeast GA | Registered: February 15, 2021Reply With QuoteReport This Post
Freethinker
Picture of sigfreund
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The approach of winter will affect whether I pursue the next stage of this topic, but the main problem with experimenting to determine whether it’s necessary to be concerned about shooting through vegetation is that it would be difficult to impossible to set up test conditions that replicate nature to an accurate degree. Natural settings are so much more random in the number and size of potential obstructions that only testing in nature can simulate nature. And then that would require a vast number of tests under different natural settings to determine anything useful, and even then any real life shot would be subject to random chance.

I’m pretty sure that my test demonstrated that a hunter could shoot through grass or nonwoody plants to harvest an animal in close proximity behind the obstructions (at least with the ammunition used). Even at a significant distance (33 yards) behind the obstruction there was no sign of meaningful deflection or other issues. But even that’s an assumption. A catastrophic effect on a bullet’s striking a skewer in my test would tell us what could happen, but no effect one time does not prove that it couldn’t happen next time. That’s the problem with small samples and negative results.

I do like the idea of the balloon test, though. If it were conducted enough times when it was partially obscured it might demonstrate something. And if nothing else, it demonstrates the need to be able to shoot from less-than-ideal positions.




7/93
 
Posts: 45893 | Location: 10,150 Feet Above Sea Level in Colorado | Registered: April 04, 2002Reply With QuoteReport This Post
With bad intent
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I'd be curious to see if there was more deflection if the barrier was placed at 5 yards vs 22.


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Posts: 7891 | Location: One step ahead of you | Registered: February 10, 2009Reply With QuoteReport This Post
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Jacob Bynum of Rifles Only did a similar test for a military or LEO course -- to test if hitting a branch caused accuracy issues. Jacob relayed the results to us civilian students in a precision rifle course. This was maybe 10-11 years ago, I didn't write down the details, and my details aren't perfect.

Jacob set up hardwood dowels some 5-10 yards in front of the shooters. Close, but not so close that the muzzle blast of a 308 might move the dowels. IIRC they tried 1/4", 1/2", 3/4", and 1" dowels. From 100-200 yards Jacob almost always uses Shoot-n-see pasters on carboard, 300+ yard targets would be painted steel. I believe they tested results out to 400 or 500 yards.

The 1/4" dowels had not repeatable effect on POI. They did see minimal deterioration in accuracy at the longer distances, but it was difficult to determine if the change was shooter, wind, or dowel.

The 1/2" dowels did have very minor accuracy effects at 100-200 yards. The shooters still hit their pasters, so the bullets didn't veer dramatically from POA. A little more effect at the longer distances, but still center of mass or vital zone hits.

The 3/4" dowels did noticeably affect accuracy at the closer targets, although hits were generally still on pasters. Longer distances showed more accuracy issues, but with some inconsistencies. The guess was that grazing the dowel had a different effect than center punching it. Knowing Rifles Only, the test ammo used 175 SMK bullets.

The 1" dowels did change POI for most shots. Some flew straight and true, however.

*****
In my own experience, Competition Dynamics holds team matches in New Mexico and Wyoming, and on occasion we've been forced to shoot through smaller branches with our carbines. Same with the 2-rifle matches at the NRA Whittington center. The obstructed targets were steel -- 3-5" at 100-150 yards and 3-4 MOA targets at 200-300 yards. The branches had no noticeable accuracy effect on my 223 ammo, which included 69 SMK, 73 ELD-M, or 75 HPBT bullets. If I could judge the wind correctly, I hit the targets.

There are a few stages at CD matches at the Blue Steel Ranch where I've shot my 6.5CM through juniper trees. Fairly small branches, trees maybe 50-100 yards out, 8-10" steel plates, targets 200-400 yards out. In my scope I've seen the branches cut & fall to the ground, or wiggle with a grazing shot. I don't recall ever missing a target in these instances.
 
Posts: 7400 | Location: Colorado | Registered: January 26, 2008Reply With QuoteReport This Post
Freethinker
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That is a great(!) report, fritz. Thank you!




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Posts: 45893 | Location: 10,150 Feet Above Sea Level in Colorado | Registered: April 04, 2002Reply With QuoteReport This Post
Master of one hand
pistol shooting
Picture of Hamden106
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I shot through a bush at a buck 12 feet away on the other side. The bush leaves were down in a late season hunt. The bush was quite open. No branch was bigger than 1/2". I had a moment of debate in my mind. But 12'? I fired. Buck went down in his tracks. The shot was broadside at the best chest location. But the hit was a real messy gut shot that appeared like it was from a shotgun.
The 165 BTHP from my 3006 must have broken up and deflected on a branch.



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Posts: 5928 | Location: Duckburg, OR | Registered: September 01, 2001Reply With QuoteReport This Post
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