Arrow Penetration Issue

[Moose2367]

Most of the replies here are spot on. Sounds like a tuning issue.
Now i've never hunted elk, but they're on the bucket list. I have hunted and killed some fairly large animals though.
As also stated, your bow isn't super fast but that should have nothing to do with your penetration issues, seeing as trad bows get pass throughs going much slower.
As Bendare has said and shown with a good pic, if your arrow is hitting at an angle and not straight, you loose all the momentum behind the arrow, which is obviously required for penetration.
I make broadheads and had a bloke say he couldn't get them to fly and thought it was because of the single bevel. I rang him and from the conversation i knew it was a tuning issue and said as much, he said he was all good in that dept, i wasn't convinced. He's a very experienced bowhunter, shooting 40-50 animals a year.
The following week he rang me back and said he french tuned and walk back tuned and his rest was ever so slightly off, now they're flying great.

 

[LDJ]

I always thought the 2 blade single bevel solid broad heads like cutthroat and kudu were for recurve/long bows. I thought they wouldnt fly good at higher speeds. Is that not the case?

 

[Jeff Martin]

I always thought the 2 blade single bevel solid broad heads like cutthroat and kudu were for recurve/long bows. I thought they wouldnt fly good at higher speeds. Is that not the case?

No, that would be incorrect. They have the ability to fly great and your speeds are far from fast/tricky.

I also agree with above, speed has nothing to do with your penetration issue.


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[Moose2367]

I always thought the 2 blade single bevel solid broad heads like cutthroat and kudu were for recurve/long bows. I thought they wouldnt fly good at higher speeds. Is that not the case?

Single bevels fly great out of any well tuned bow. It's all i use(seeing as i make them). I have a few bows, the fastest would be an Obsession Evolution 80lb and have zero flight issues.

You are best off matching the bevel with the fletching, as in right had shooters usually use right helical or offset, so use a right hand bevel. The bevel has a very slight effect on helping the arrow spin in the same direction as the fletching.

It why you see an 'S' twist into a target when using single bevels.

 

[Gumbo]

I don't think two less than perfect shots justify worrying about penetration issues. Less than perfect arrow flight might be a problem, but you should be able to see that while shooting at longer range (40+ yards) both in flight and in your groups. I wouldn't jump to the conclusion of that being the problem, or that there even is a problem. Maybe shoot with a friend and compare penetration into a target?

I have some shots that are perfect that get little penetration and some that are off and get a pass-through (and my bow is tuned). Likely you just had bad luck. Sounds like you went a bit overboard on arrow weight, and consequently may have ended up little underspined (I shoot 300 spine Rampages with 75gr HITs and 100gr points at 70 pounds and 28.5 inch draw, 28 inch shaft). But again, you could likely see any significant issues with arrow flight while shooting. I would suggest getting your arrows in the 450 grain range to increase FPS back to 280ish. Then make sure your bow is tuned, and most importantly...focus on keeping it together and making a good shot, both in shot placement and form.

 

[Brendan]

Probably the best analogy on how an arrow works is through vectors.

If you think of your arrow as a row of ball bearings then you can see how important perfect arrow flight is- see diagram. The arrows penetrating force is multiplied many times when all of the ball bearing [the actual arrow weight] is focused behind the BH. Conversely, you lose a huge amount of an arrows energy if its not flying perfectly straight.

When the arrow hits at a slight angle, you no longer have a multiplying force of the whole arrow...but now every segment applies a vector force only partially to the segment in front of it.
View attachment 62473

I had my son do the actual math on this vector force [way beyond my paygrade!]...and numbers wise- its significant.


The physics of it is the same using a train or water pressure in a pipe [Water Hammer] ...anything with mass...they all act the same. Fletching helps of course...and this is the reason why we sometimes hear guys saying they get better arrow effectiveness on longer shots as their arrow flight has had time to correct.

We've talked about this before - but I think you're overdoing this a little(and you do start to allude to why at the end). And this is coming from someone who agrees you should strive for perfect arrow flight...

An arrow that starts off at an angle will stabilize due to the vanes and rotation of the arrow. Basically - an arrow that starts like that will at some point down range transition to straight and true arrow flight (even though it may be in a slightly different direction than intended, and you've lost some energy due to stabilizing it). That's why you can see a paper tear at close range, but it won't be there the further out you go. The trick is - how far down range that happens is dependent on a lot of factors...

I'm not saying arrow flight / tuning isn't contributing at all, but looking at the specifics of the OP's setup - My bet is on shot placement. (1st year - 40 yards, behind last rib, 2/3 up body. 2nd year - 20 Yards, quarter to, half way up, behind the shoulder...)

 

[LDJ]

Ok this is what I found. Nock tear right and slightly down. I got the down fixed. But I have a QAD rest and I cannot move the rest away from the riser. Only adjusts up down right left. Any suggestions?

Also put it on my draw board and the top cable stop hits the TOP cable while the bottom stop has about 3/16” before it’s touching the cable. I don’t know how that would be corrected on a HTR or if it matters.

 

[Beendare]

Ok this is what I found. Nock tear right and slightly down. I got the down fixed. But I have a QAD rest and I cannot move the rest away from the riser. Only adjusts up down right left. Any suggestions?

Ok so its arrow flight...good on you to go through the tuning process. It will probably surprise you how much better of a shot you actually are when you shoot a tuned setup. Take it to a good tuner, watch and ask questions. Have them look at your form too- what the heck...we can all be better shooters. Please report back when you get it dialed...I'm betting you shrink your groups significantly.

Brenden, I see a lot of guys with poor arrow flight.
Have you spent much time at an outdoor range? I just got back from the work party at ours and can tell you that over 1/2 of the guys shooting had poor arrow flight...and some of them are club members that should have known better.

Its easy for good archers and tuners- smart about their setup......to underestimate the problems avg archers have with arrow flight.
These guys were all shooting FP's standing on flat ground........add BH's uneven ground and the circumstances of a hunting shot and its a big problem for a lot of guys. its not at all like shooting stationary targets with all day to squeeze off a perfect shot.

.

 

[mfllood3800]

OP stated not all arrows are consistently penetrating the block target the same- this is a tuning, or arrow issue, or both.

No doubt his shot placement wasn't the best and very well could be the reason for poor penetration. But he has tuning issues as described in his target results with arrows at different angles as well as cam timing being 3/16" off.

I also read on here speed has nothing to do with penetration. Not sure how this can be possible.
I prefer a heavy arrow as that is what gives me the momentum to get great penetration. but I also utilize speed to get that momentum going.

If you have a 500 gr arrow flying at 100 FPS, do you think it would penetrate the same as that same 500 gr arrow flying at 330 FPS?

We can argue on set up, fletching, FOC, Spine, KE, Momentum FPS, what ever causes issues and be just like AT.
Or
we can encourage the OP to get that bow tuned up, as it sounds like he is, and work on form and repetition to get better shot placement so next year he posts in the 2018 success photos threads.

I don't know your bow, but my cams have to be synced and I twist cables to get that done. Sounds like you have some good tools to do the job right and glad to hear you are doing it. Next year is gonna be a better year as you confidently hit the woods knowing your gear is right.

 

[Neverenoughhntn]

Obviously, proper tuning is first and foremost as has already been covered.
I'll keep this brief... years ago I thought that speed was everything along with everything tuned to the extreme.... I had a couple instances where I was was less than content with penetration. After extensive research, I ended up going to the extreme opposite end of the spectrum and haven't looked back.
I now shoot BE rampage, 56 gr half-out SS insert, and abowyer 200gr screw in bonehead BH (2 blade, single-bevel). I've taken several animals with this setup (deer and elk) and have been impressed every time. I shot a bull 2 years ago at 30 yds, quartering away... arrow entered at last rib and went through far side scapula (half of the arrow was hanging out the exit side after going through the scapula before it got broke off) ... I know that this set up is a bit extreme for most, but given the topic of discussion I figured I'd share my experiences anyway. It's not for everybody, but definitely works for me.

 

[neverquit]

I passed thru a bull in nov at 40 with much lighter arrrow. I shoot a elite impulse 34 28.5dl. Eaton axis 340 with a 100 grain grave digger. Total arrow weight is 420, 295fps. I too hit a tough high becaue I’m a knuckle head and hit a small limb that I didn’t see. But still complete pass thru double lung high never found my arrow. But dead bull 150-200yards. Not much of a blood trail but enough.

I’d lean toward tuning but I don’t think my arrow was flying true after hitting a limb.

 

[Brendan]

Brenden, I see a lot of guys with poor arrow flight.
Have you spent much time at an outdoor range? I just got back from the work party at ours and can tell you that over 1/2 of the guys shooting had poor arrow flight...and some of them are club members that should have known better.

Its easy for good archers and tuners- smart about their setup......to underestimate the problems avg archers have with arrow flight.
These guys were all shooting FP's standing on flat ground........add BH's uneven ground and the circumstances of a hunting shot and its a big problem for a lot of guys. its not at all like shooting stationary targets with all day to squeeze off a perfect shot.

.

I'm not arguing you shouldn't tune your bow - I've spent thousands of hours at the range and do all my own setup and tuning - you and I have been through this exact subject before. But - your nice little diagram that you've posted before is not 100% correct, it over-simplifies it. That's more my point. The fact is - that an arrow that starts out imperfect, will eventually fly straight and true unless you have something really crazy happening that the vanes just can't stabilize the arrow. I've tested and proved that at the range - have you?

Look at the OP's first year's shot. 40 yards. Arrow should stabilize by then unless something's way off or he's not using enough vane. And with his setup - that would have been plenty of energy on impact. Behind the last rib - potential gut shot and dealing with potential full stomach. 2/3 of the way up the body - getting close to the spine.

So yes - strive for great arrow flight, but I don't think there's one thing you can blame it on. I think less than perfect shots in both cases contributed.

OP - here's how you fix it depending on your bow, cut and paste from my tuning notes. I'd sync the cams first then the right / left.

Nock Right - Broadhead misses Left
• Broadhead hitting left is the same as bareshafts hitting left or a tail right tear.*
• Tighten Right Yoke
• Loosen Left Yoke
• Rest Left
• Shim Cam(s) to the Right
• Crank down flex guard for more sideways string pressure / more string clearance.

 

[Slim Jim]

I haven’t read everyone’s replies but arrow flight can cause this and not just a tuning issue. If you tend to grab or grip your bow as you release the shot will cause erratic flight. Video yourself and make sure your bow hand stays completely relaxed after the shot. Sorry if this has already been explained


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[Beendare]

Look at the OP's first year's shot. 40 yards. Arrow should stabilize by then unless something's way off or he's not using enough vane. And with his setup - that would have been plenty of energy on impact. Behind the last rib - potential gut shot and dealing with potential full stomach. 2/3 of the way up the body - getting close to the spine.

So yes - strive for great arrow flight, but I don't think there's one thing you can blame it on. .

You know we are pretty much saying the same thing, right? I said in my first post....arrows will straighten out on longer shots. Poor arrow flight causes poor accuracy...thats a given. If he is way off....and the OP stated that later....arrow flight downrange can still be be an issue. You make a lot of assumptions to come up with your conclusion in your last post....all we really know for sure is the OP has bad arrow flight and is working on correcting it. The rest is speculation on your part.

As to my drawing being oversimplified....its physics bro and I can tell you I've seen the math on this is and its not 'simple' by any means....please explain where it is wrong.

 

[mfllood3800]

Obviously, proper tuning is first and foremost as has already been covered.
I'll keep this brief... years ago I thought that speed was everything along with everything tuned to the extreme.... I had a couple instances where I was was less than content with penetration. After extensive research, I ended up going to the extreme opposite end of the spectrum and haven't looked back.
I now shoot BE rampage, 56 gr half-out SS insert, and abowyer 200gr screw in bonehead BH (2 blade, single-bevel). I've taken several animals with this setup (deer and elk) and have been impressed every time. I shot a bull 2 years ago at 30 yds, quartering away... arrow entered at last rib and went through far side scapula (half of the arrow was hanging out the exit side after going through the scapula before it got broke off) ... I know that this set up is a bit extreme for most, but given the topic of discussion I figured I'd share my experiences anyway. It's not for everybody, but definitely works for me.

Yep, I too used to be all into speed.
But I have come full circle to a better arrow for momentum.
How ever, I still want to have decent speed with a heavier arrow.

My old set up was under 400 gr and like 340 FPS- all pass thru's but one
- it just takes that one to change your mind and until you have it, you will always disagree.

Now I run almost 500 grains, but still have a FPS of 300 or so, knowing a bit more speed gets me there a bit quicker keeping an animal from reacting and ducking, causing bad placement after a good shot.

Everyone is unique, cause bows, arrows, and animal scenarios are all unique.

Lots of good info here from people.

 

[NevadaZielmeister]

With your setup, you shouldn't have any problems with penetration, but I agree your shot placement is not the best. That aside, I think you have some tuning issues that need to be addressed. So let's start at the beginning and work our way up from there.

1)...... BE CONFIDENT IN YOURSELF AND YOUR EQUIPMENT.

This is all by far some of the best advise I can think of regarding tuning and accuracy. Thank you for this post.

 

[Brendan]

As to my drawing being oversimplified....its physics bro and I can tell you I've seen the math on this is and its not 'simple' by any means....please explain where it is wrong.

We are agreeing on some things. You're not wrong in concept, but not really representing everything 100%. You referenced the math being complex, but it really isn't, here's an example:

3" Paper Tear. 28" Arrow. Calculate the angle then use that to calculate the force vectors. That equates to retaining over 99% of the force down the axis of the arrow. Granted you'll lose more energy at impact, but that's the physics, bro, and it is pretty simple to calculate (Two engineering degrees here, I enjoy this stuff, not trying to be argumentative....)

Here's some testing data for you too from the range this past year - I tested a ~2" paper tear at the bow, that was a bullet hole by 30 yards (moved my paper tuning rig to different ranges). That means that even with an initial tear in that case - I was back to perfect arrow flight, even if "off target" in the accuracy department.

So yes, it's all speculation what actually caused the penetration issues, but the only thing we know for a fact is that the OP admitted to making a less than perfect shot, and that he has a tear leaving the bow. We don't know that his arrow was impacting at an angle. That was my point. Yes, it still is 100% the right thing to do to tune your bow, get rid of the tear. I just think it impacts accuracy much more than delivered energy. And although I've heard people argue otherwise - I've never seen any data to back it up.

And - I will happily eat crow if someone can come back with an actual test that shows different...

 

[Topo_trekker]

Ok this is what I found. Nock tear right and slightly down. I got the down fixed. But I have a QAD rest and I cannot move the rest away from the riser. Only adjusts up down right left. Any suggestions?

Also put it on my draw board and the top cable stop hits the TOP cable while the bottom stop has about 3/16” before it’s touching the cable. I don’t know how that would be corrected on a HTR or if it matters.

I had the same problem this year with my QAD rest. I tried everything, then switched to a lower profile and longer vane. Fixed the problem. Also make sure your nock fit is absolutely perfect with the serving size you're using.

Arrow setup is fine. I shoot 450g total at 68.5# with pass through on elk. Exodus swept broadheads.


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[LDJ]

I’m making progress. Put 1 twist in my top cable so both stops are hitting at the same time. That made a big difference in my center shot. Went from 1” to 3/4”. Went from 2” tear right to bullet holes on paper. Walk back tuning went fast. My first group at 20 yards was the tightest I’ve ever shot with this bow. 4 arrows in a 3/4” group. All arrows entered the target in the same direction.

I did change rests also. Went to the Hamskea hybrid pro hunter. The micro adjustment made things really fast.

I’m embarrassed I I didn’t get this worked out when I bought the bow but very thankful for the help y’all have offered. Great learning experience.