A little more broadhead testing heavy arrows

[Ryan]

To add to the previous post I decided to take up the suggestion of some and, some heavier weight arrows and see if that made a significant difference in penetration. I got a hold of two Easton Axis FMJ Dangerous Game 300 spine arrows with the brass inserts. Fully assembled with the 125 grain points as before they weigh 682 grains. Shot out of the exact same bow as before they shoot 232 fps for a bit over 81 foot pounds of kinetic energy, more energy than before, which suprises no one. The target is the same and so are the broadhead weights, 125 grain. I went with the leader before, Slick Trick Magnum, and my second preference, Solid Legend. Again, three shots at 20 yards and took an average.
Results:
Slick Trick Magnum- 66.27 cm very consistent between the three shot with a difference of only 1.7 cm between best and worst depth.
Solid Lengend- 65.60 cm. Wider variance of 4.5 cm.

Conclusion: Honestly, I'm surprised. I expected deeper penetration for both. From previous tests the Slick Trick actually decreased substantially, 9.1 cm, or more than 3 inches. I recall the arrows with Slick Tricks going beyond the nock into the target last time and they never did this time. The Solid was basically equal, decreasing .03 cm. The difference between the two broadheads decreased a lot.

I'm not an advocate of lighter/faster equipment by any means but this, at least preliminarily, tells me that there is a point of diminishing returns concerning heavy arrows. I'll admit this is not a huge test group and the target isn't perfect but it is some interesting results. I'm going to stick with my 500.5 grain arrows with either head with confidence for anything up to an eland. Besides this testing, doing some research I've found plenty of eland have been killed with a lot less.
Less than a month until I fly.

 

[firehuntfish]

Ryan,

There is a Bell curve that correlates to exactly what you have discovered in your testing. There is definitely a point at which the weight will affect the arrow to the point that it will loose penetration despite the same or even slightly increased increased kinetic energy. It's actually a great idea to conduct a field test like you have done to determine where that point is for your particular set-up.

It's great to get recommendations from others with similar set-ups as to what total arrow weight to be using, but I always stress that this should only be a starting point. So many variables come into play such as broad head choice, arrow shaft diameter, arrow weight/spine, fletching choice, and the overall tune of the bow itself. Any variation can really affect the outcome of the penetration tests. Simply settling with the set-up that works for someone else is rolling the dice a bit. I always recommend trying a few different arrow/broad head combinations to determine the best overall performer before heading off into the field, especially when the field is Africa. Looks like you have done your homework.... Best of luck on your hunt!

 

[BRICKBURN]

Looks like your research is done and you just need to practice with your set up for a month.
Have fun.

 

[jeff]

There might be a spot were you get the best of both worlds, but there is a reason buffalo and ele hunters are use 8oo- 1200 grain arrows, its not because they want less penetration.

 

[Albert GRANT]

Just for fun and curiosity, if you have access to some 180-200 grain 2 blades throw those on and see what you get for penetration. Might surprise you- might not with your setup. Worth trying though

 

[Ryno Botma]

My 2 cents , I have seen on plains game that lighter faster arrows with good quality broadheads work better and get more penetration and work good on anything up to eland

But as mentioned you have a curve on your setup that you will start to loss performance

On buffalo and giraffe you need momentum and an arrow
That hold together

However I have guided hunts on buffalo with Matthews reason 70 pound with arrow weight 700gr two blade grizzly tip and had full penatration on Buffalo broadside

In my opinion if you are only going for plains game 500 gr with good quality broad head (fixed blade) preferred you will be fine

practice shots out to 50 yards a lot for that big smart kudu bull that will not come closer until its to dark

Happy hunting

 

[firehuntfish]

There might be a spot were you get the best of both worlds, but there is a reason buffalo and ele hunters are use 8oo- 1200 grain arrows, its not because they want less penetration.

Jeff, There definitely is a point where you get the best of both worlds, and a simple field experiment like the one Ryan did is a good way to determine that.... Your point about utilizing 800-1200 grain arrows on dangerous game is a slightly different scenario with the set-up, but the bell curve still applies. . Hopefully, Anyone shooting an 800+ grain arrow is drawing at least 75lbs. In fact, 80-100lbs, would be much more appropriate to generate the necessary kinetic energy to make a heavy arrow like that penetrate with any effectiveness.

I would hope that anyone hunting dangerous game (or any game for that matter) with a bow would be very familiar and well-practiced with their set-up before shooting the first arrow at an animal. This is NOT the time you want to guess or assume how your set-up will perform. Not only is it unethical, it's pretty darn dangerous.

 

[jeff]

Firehuntfish the test has some merit but by shooting a heavier arrow with same broadhead changes the FOC and also spine so tune is a issue, I would want to make sure both bullet hole through paper to make sure energy is not lost at launch and few yards of flight. Dr. Ashby's tests and the tests conducted by Alaska Bowhunting Supply are available on youtube and are worth considering.

 

[kathy]

I think you need to test a heaver broadhead,
I would be willing to bet a 175 grain 3 blade VPA will penetrate deeper than your 125 grain slicktrick.
I think the heaver arrow needs a heaver broadhead. Forrest

 

[Lee M]

Ryan. Good info. Thanks for sharing. I'll be doing some testing shortly with a dozen of the same DG FMJ you mentioned that I just bought. I plan on getting up to the 800 grain range. I'll post data when I have sufficient info. I shot two different 500 grain arrow combos (regular FMJ and 100 gr slick tricks & a carbon arrow and 150 grain VPA) for my safari in 2014 and took numerous plains game with full penetration and no issues. 500 gr is a good combo for speed (closer pins) with adequate weight for good penetration on plains game. I shoot 73 lbs. I do however think that if I am going for Buff or Giraffe I would need 800 or so grains. And I believe this would out penetrate my 500 grain combo if tuned properly, including getting the correct arrow Foc for the heavier arrow, out of my 73 lb bow. There are so many different factors that go into a test like this that makes it challenging. Without good arrow flight max penetration will not be achieved. I do think you may have needed to change the Foc on your heavy arrow set up as I have read Foc has a big impact on penetration. Your new heavy arrow was 40% heavier so the Foc probably decreased. Also, did you completely retune (paper, drop back, etc) with the new heavier set up? Thx

 

[Ryan]

One of the nice things about this from the start was I knew this set up with any of these heads would do the job. I've been bowhunting for over 25 years now and I recall people using similar weight arrows and broadheads in the late 80's with a lot less speed and killing every plains game animal up to eland dead as disco. This testing was to see what would do the job better on those species. Were I to hunt a buffalo I'd go with at least 75 pound draw bow and the DGS shafts with 175 grain heads probably to put it all over 700 grains. And I'd be doing some tests.

No fears on practicing, I do 2-3 times a week up to 70 yards.

I did in fact check tune. The DGS arrows shot through paper perfectly and I shot them out to 40 yards to see the difference in drop. At 20 my 30 yard pin worked perfectly, at 30 the 40 did the same, at 40 the 50 yard pin had the arrow hitting 3 inches low. As for FOC, the DGS brass inserts are something like 50 grains heavier than the usual aluminum ones which I figured would balance the FOC out on the heavier shaft. Checking real quick right now the DGS shafts are 1/4 inch more FOC than the regular FMJ shafts. So all around similar with only one major variable different, weight, just what I was after for testing.
Sometime or another a comparison of the heavier broadheads would be interesting. Say 175 grain Solid Legends and DRT's for four bladed ones and some of the different 2-bladed heads and maybe a 3 blade to see the differences. Legend heads were a suggestion of a friend who had used a 2 bladed Alaska Bowhunting Supply head on a DGS shaft on an Australian water buffalo. He's an excellent shot and had two good pass throughs in the vitals with absolutely no blood trail. The single cut's sealed up on both sides with the thick hide. He did find the buffalo but he swears he'll never use a 2 blade again. I too have always preferred 3 or 4 blade heads for a more open wound and greater internal damage in my opinion.
Good hunting all.

 

[jeff]

If you get more KE and more Momentum it would defy the laws of physics not to penetrate more all else being equal.

 

[Ryno Botma]

The only problem I have with 3 or 4 blade on Buffalo and giraffe is more resistance that give less penetration

The Buffalo that I have hunted all gave very little blood trail hense their thick skin fortunately we have very good trackers that work only on track and found the animals all stone dead

 

[Albert GRANT]

The only problem I have with 3 or 4 blade on Buffalo and giraffe is more resistance that give less penetration

The Buffalo that I have hunted all gave very little blood trail hense their thick skin fortunately we have very good trackers that work only on track and found the animals all stone dead

I will take a tough to track, dead buffalo over one with a little more blood but only single lunged and pissed off any day!

 

[firehuntfish]

Jeff,
The conversation is getting a little technical so possibly my inferences were not clear. I believe we are saying the same thing... You are pointing out that the field test Ryan did revealed less penetration because he only increased the weight of the arrow and not the weight of the broad head, thus changing the overall dynamics of the components chiefly the FOC? If that is what you are saying, I agree completely. Refer to my original post below:

So many variables come into play such as broad head choice, arrow shaft diameter, arrow weight/spine, fletching choice, and the overall tune of the bow itself. Any variation can really affect the outcome of the penetration tests

The testing by Ashby and ABS are good reference tools, and there are dozens more good demos that reveal the same physics. What I am saying is that it's a good idea for anyone to conduct some home field testing with several different arrow/broad head weights and combinations to see what will perform best from your particular set-up.

The only problem I have with 3 or 4 blade on Buffalo and giraffe is more resistance that give less penetration

Ryno,
It would seem logical, but not necessarily true.... It would depend on the design of the broad head. This is where testing out different combos would pay off... For example, my 3-blade Muzzy MX-3's penetrate much better than any of the 2-blade fixed broad heads that I have experimented with. The head design and profile of the blades can have a big effect on the penetration even with all other variables being equal. This is the problem I have witnessed with mechanicals which are a perfect example of this.

 

[Ryno Botma]

I had a look at the muzzy mx3 they look like very good broad heads do you know if anyone ever used it on buffalo before ?

 

[Ryan]

Jeff,
The conversation is getting a little technical so possibly my inferences were not clear. I believe we are saying the same thing... You are pointing out that the field test Ryan did revealed less penetration because he only increased the weight of the arrow and not the weight of the broad head, thus changing the overall dynamics of the components chiefly the FOC? If that is what you are saying, I agree completely. Refer to my original post below:



The testing by Ashby and ABS are good reference tools, and there are dozens more good demos that reveal the same physics. What I am saying is that it's a good idea for anyone to conduct some home field testing with several different arrow/broad head weights and combinations to see what will perform best from your particular set-up.



Ryno,
It would seem logical, but not necessarily true.... It would depend on the design of the broad head. This is where testing out different combos would pay off... For example, my 3-blade Muzzy MX-3's penetrate much better than any of the 2-blade fixed broad heads that I have experimented with. The head design and profile of the blades can have a big effect on the penetration even with all other variables being equal. This is the problem I have witnessed with mechanicals which are a perfect example of this.

As I mentioned last night, while the broadhead was the same I did use a heavier insert to add weight and keep the FOC point similar. It did, though slightly more tip heavy. So the dymanics didn't change, just the weight.

 

[Lee M]

Good info and comments by all. Regarding two blade having better penetration vs 3-4 blade heads - I have heard the the big difference is when hitting bone. 2 blade have an advantage of being able to split bone and continue to penetrate. Not an issue with plains game but certainly more a concern with the big critters

 

[firehuntfish]

I had a look at the muzzy mx3 they look like very good broad heads do you know if anyone ever used it on buffalo before ?

I wouldn't recommend them for an animal the size of a buffalo. Although they are one of the more compact, heavy duty fixed blade designs, I wouldn't put them in the super heavy duty use category. Also, I don't think they make them heavier than 125 grains. There are definitely more appropriate choices for the larger dangerous and plainsgame.

 

[Lee M]

I'm planning on trying heavy 2 blade (maybe 250 grain VPA) on my heavy arrow. If I get it stable and flying well I may go for one of these