Broadhead Vents and Penetration

KentuckyTJ · March 25, 2011, 02:47:00 PM

I wonder if the open vents in a broadhead as they are passing through a deer or anything else for that matter would actually cause friction loss as stuff hung in them? Or would the entrails be thrown aside with the cutting force as the head passes through?

March 25, 2011, 03:02:00 PM

i have shot a number of deer with Deadheads and Hills of both single bevel and standards. some were only file sharpened and some were honed. I have only once had an arrow stop in the deer, ball joint of the far shoulder. I have never noticed more than one or two hairs pulling along with the head, even ones that were sharpened per Hill instructions. I have noticed that if a Deadhead is not mounted straight it can make a really cool warbling sound when shooting them cross wind. Seems to me that if the head did stop in the game, that is when the vent gaps would develop some grabbing action on near by tissue. My wife put a an arrow clear through a deer with the smaller 135 Deadhead and she was using a 37@ 26" bow at the time with a 5/16" cedar shaft. i was more concerned about the whistle than the penetration with her setup. She said it whistled right through the deer.

Stumpkiller · March 25, 2011, 03:08:00 PM

I have no evidence one way or the other, but my gut feel would be it doesn't hurt penetration. The blade has opened a path that the rearguard metal along the backside of the vent will pass through. Only two vented heads I've ever used are Bear Razorheads and Zephyr Sasquatch. The Sasquatch was hindered by width, IMHO, in my weight of bow (60#) but that big bar across the trailing edge does look suspect now that I reconsider. It's the only head I ever put in a deer that resulted in a lost deer - I believe a one-lung shot that made it to a deep water swamp and I couldn't find it in three days of trying. Nice, long tined 8-point from about 4 yards; but a foolish downward shot into it's back on my part.

steadman · March 25, 2011, 03:08:00 PM

When something sharp hits live tissue, the tissue moves away from said blade. I don't think vents have any factor in it.

lpcjon2 · March 25, 2011, 03:27:00 PM

IMHO the vents would act like the blood spoon on a knife and helps release any suctioning that occurs when an object passes through muscle/tissue/.which can slow down the momentum.

March 25, 2011, 03:42:00 PM

If an arrow is not flying right or gets going sideways in flesh, penetration goes way down anyway, however, I could see that it could be possible if that happened, that the backsides of the gaps could impair penetration more. I have heard of cases where very close shots out of tree stands have resulted in minimal penetration, but that could be as much a result of an arrow not having recovered coming out of the bow as anything else. If in doubt one can always stick with the good old pass through standards like Zwickeys and Grizzlys.

Bjorn · March 25, 2011, 03:51:00 PM

I would make sense that it slows things down; perhaps not enough to matter.

Ragnarok Forge · March 25, 2011, 04:52:00 PM

Speaking from the engineering perspective, based on physics and fluid dynamics, yes it will slow the arrow down compared to a smooth blade broadhead of the same shape, size, and weight. How much? Not enough to matter! Friction, fluid drag and eddying, tissue impingment, it is a very long list of factors affecting the head drag in tissues friction coefficients. The differences in that small of an area are really minimal. If your shot is from a good angle the head will still penetrate all the way thru a deer size animal. On a bad angle shot, or a deer turning as it is hit and a hit in the paunch or guts, etc... then this could make more of a difference. Enough to keep you from making a kill instead of a lost deer? Perhaps.

Stumpkiller · March 25, 2011, 05:08:00 PM

This is a great cold night around the coal stove discussion.

I agree a blade can't be blamed for a bad angle -at least not vent vs. non-vent. I likely hit a rib root near the spine the way the deer reacted (down in a heap, motionless for 30 seconds and then struggling & finally off at run - with 20" of a 600 grain arrow sticking up out of it's back). Paradox, probably under-drawn from the extreme downangle, poor judgement. Believe me, I punished myself greatly - including changing my broadhead after I got home from spending the last three days of a canoe-in trip tring to find that deer. I had been with Magnus MA125 and went (then) with a RibTek 125S. I'm thinking either of these would have gone down through and out the bottom even with a bone hit. I any of them had hit the spine solidly the deer would have been down longer.

Over&Under · March 25, 2011, 05:16:00 PM

QuoteOriginally posted by lpcjon2:
IMHO the vents would act like the blood spoon on a knife and helps release any suctioning that occurs when an object passes through muscle/tissue/.which can slow down the momentum.

Those were my thoughts, but I couldn't figure out how to say it....thanks jon2!

bsoper · March 25, 2011, 05:24:00 PM

Interesting. I would think along the same lines as the blood spoon, but probably it isn't noticeable.

wv lungbuster · March 25, 2011, 05:30:00 PM

I think that vents would cause more friction. Kind of like a snagging effect.

lpcjon2 · March 25, 2011, 05:42:00 PM

Wheres Rob D on this one...LOL

Over&Under, your welcome took me a few minutes to put it into words also.

treetoppredator · March 25, 2011, 06:15:00 PM

I don't know if they would affect penetration, but if you ever have to dig one out of a tree, you'll see that they are way harder to get out than a smooth blade. The wood fibers and splinters get wedged through those vents and make broadhead retrieval darn near impossible!

Gray Buffalo · March 25, 2011, 06:57:00 PM

I don't like RibTek's because the ribs do collect hair and tissue. As for the vents, they are in line with the blade and IMO do not cause a problem

Chub · March 25, 2011, 07:51:00 PM

ill be checking this thread was wonderin myself

maineac · March 25, 2011, 08:20:00 PM

I think there is something on this in the Ashby reports, but can't remember which one. I think vents do impair penetration, but on deer size game the effect is probably negligible. I believe tissue has a more fluid like behavior than most of us imagine. The flow back after he cut is quicker than we can picture, and results in some drag. That being said I have not moved to the solid blades yet. Haven't had enough opportunity to field test my current woodsmens yet.

Earl E. Nov...mber · March 25, 2011, 09:08:00 PM

Muscle is like a bunch of rubber bands under tension. When it is severed, the fibers retract just as a rubber band.. That along with the natural lubrication of blood is why I feel the BS about improved penetration due to a small shaft size is a bunch of hooey.. along the same lines I doubt if vent in the blade would would be an issue. The edges on a ferrules such as a Rib-Tek or the old Ben Pearsons would be a different matter

Friend · March 25, 2011, 09:26:00 PM

Using the same arrow set-up, my large snuffers do average approxiamtely an inch less penetration than my Big 3's. I had attributed the lower pentration due to the vents. The vented head is noticeably more difficult to extract, pulls out chunks of the target material, and typically require some target material removal prior to the next shot.

Just an observation and I don't have any factual data of expecting the similar results on game. Just the same. I still suspect that the vented blades could impede penetration. An inch difference on a Rhinehart BH target seems significant to me. Big Jim did not get a complete pass thru using an 80#'s @ 30" and a 780 grain arrow. I will error on the side of caution.

Don Stokes · March 26, 2011, 09:58:00 AM

I'm with Earl. Cut a big hole and the arrow will follow!