Spitfire Problems
 

I started using NAP Spitfires last year. Took a nice doe, but was kind of unimpressed with the penetration. My son Steve put a good hit on another doe using the Spitfire, but did not appear to get good penetration, and was unable to recover the animal. He recovered the arrow and found only two of the blades had opened. On opening evening this year, I had a 20 yard quartering away shot at a doe. The shot was true, but when she blasted off I noted the arrow flopping around, with minimal penetration. I found the arrow about 20 yards from the point of impact, blood only a couple of inches up the shaft, and NONE OF THE BLADES OPEN! No blood trail, no recovery. Disgusted, I switched back to my old standard NAP Thunderheads and took a nice 6 point the following evening. Great penetration and blood trail, the buck only went 50 or 60 yards. I' m using 100 grain heads, shooting a 64 pound pull, and generating 230 fps. Has anyone else experienced this with Spitfires, or am I doing something wrong?

RE: Spitfire Problems
 

I haven' t had the same problems but 1 thing to be aware of is that the blades close whether the arrow backs out or blows right through. They always open in the deer. The act of pulling out closes the blades completely and due to the release of pressure when coming out the far side of the deer .. the blades spring closed as soon as the clear hide.

One thing I never did like was the fact that if you have an arrow penetrate a deer but not make it out the far side ... if that arrow slides backward a few inches the blades start to close and you no longer have any cutting surface moving around inside the deer as at is running away. Just like the fact that mechaicals are so much safer than fixed doesn' t get mentioned often .. I think this point gets looked over frequently .. as I would imagine a fixed head, razor sharp blade bouncing around the body cavity of a deer would do FAR more damage than any mechanical that has closed as the arrow started to back out.

RE: Spitfire Problems
 

A friend of mine glued his blades shut on a spitfire, to use as a practise head, and accidentally used that head to kill a buck. Double lung pass-thru, went 50yds and piled up. I don' t think your shot went where it was expected.

RE: Spitfire Problems
 

Excellent point (no pun intended). However, when I recovered my arrow, I opened each of the blades. All had blood on the part of the blade that would show when closed, but each was clean where it was folded in, that is, on the cutting surface. I' m speculating that it hit a rib and somehow didn' t penetrate enough to open. At any rate, I' m staying with the fixed blades, which have never let me down. Anyone wanna buy some Spitfires cheap?

RE: Spitfire Problems
 

Not knowing how heavy your arrows are I just calculated your Kinetic energy using a 350 grain and 400 grain arrow weight. The results were 41lbs at 350 and 47lbs at 400.

I don' t believe you are pushing enough kenetic energy to get full penetration with a mechanical head of any kind. They will fly straight and true but your lack of penetration and your sons are evidence enough that you should both be using a head designed for maximium penetration.

It' s sounds like your Thunderheads have been good to you........stick with them.

I am going to say this as politely as I can........A little bit of research on you or your sons part could have prevented 2 lost injured or dead deer. Live deer are not for testing out heads to see if they work.

Couldn' t reply without saying that........I hope you see I am just trying to help you........and the deer ;)

RE: Spitfire Problems
 

I was watching the H.S Strut Primetime7 DVD the other night. There were 2 hunts were the hunter was using spitfires. Both times penetration was minimal. The deer ran off with 1/2 the arrow sticking out.

RE: Spitfire Problems
 

Atlasman, you could not be more correct. And I truly regret both my son' s and my experience. I don' t know how to calculate kinetic energy but would like to learn. Don' t know the grain weight of my arrow (seems like for a guy who' s bow hunted successfully for a few decades there' s quite a bit I don' t know), but it' s a 28 3/4" 2413 XX78. Any suggestions would be welcome.

RE: Spitfire Problems
 

Couldn' t have said that better myself !!
Your not pushing enough energy ! Spitfires are not a good choice for low KE set up' s , but for me at 70 # of KE they blow through deer like a hot knife through soft butter ! You need to know your set up' s capabilities !!

RE: Spitfire Problems
 

Mr 4pt...Show em please :D

RE: Spitfire Problems
 

tnichols, I agree with you, on most videos I' ve watched in the Prime Time series, if penetration is minimal, the head is almost always a spitfire. However, on PT7, the first deer shot by Rick White is taken with a spitfire, complete pass through at about 25 yards broadside. They don' t get into the different bow set ups the guys are using, so one can only assume Rick' s is adequate, the others suspect for spitfire use.

RE: Spitfire Problems
 

AtlasMan,

I appreciate your comments about Kinetic energy opening mechanicals. As a relatively new bowhunter, I migrated to mechanicals for the same reasons as everybody else.

How can I quickly and simply calculate what Kinetic energy I am creating?
What is the minimum necessary for efficient use of a normal mechanical?
Are there some mechanicals (ie 1.25 " blades vs 1.5 " blades) that require less KE?
Is the shot distance important (ie up to 20 yards there is enough KE while at 35 yards there is not enough KE)?

I appreciate your help on helping me figure this out before I run into problems.
Chrisvst

RE: Spitfire Problems
 

Feet per Second X Feet per Second X Arrow weight in grains DIVIDED by 450,240 = Kinetic Energy.

Or, you can go to the Bow Jackson Archery site and use his on-line calculator :)

RE: Spitfire Problems
 

Bow Jackson site also has a trajectory calculator giving you the ke at distances. You can also figure out arrow weight and FOC as well as many other things !!

Good site !!

RE: Spitfire Problems
 

I wouldn' t shoot mechanicals without shooting 250+fps. Just my opinion, but your lacking in speed to shoot Spitfires.

RE: Spitfire Problems
 

www.bowjackson.com

If I remember correctly you want to have 55lbs KE minimum to shoot mechanical heads effectively. Even then you should stick with the smaller cutting diameters of 1 1/8" for example.

I may be off on my figure there so anyone feel free to chime in.

Shooting bigger heads like 1 1/2" or 2" cutting diameters requires even more. If you are marginal then just play it safe and shoot a fixed head. There has to be one out there that will fly right for you. I myself bought 3 sets of heads this year. Magnus 100 grain Stingers 2 blade.......SteelForce 100 grain 4 blade serated.....and Muzzy 100 grain 3 blade(These were sent to me free by Muzzy because I had trouble with the 90 grain 4 bladers last year)

I myself believe if you are under 60 lbs KE you are asking for trouble with penetration of a mechanical head.......I was in the mid 50' s last year and the buck I shot with a WASP JAK-HAMMER.....the head stopped at the opposite side hide. Between the ribs through the lungs and right through the middle of the heart (see pic below :D).........I would hate to think what would have happened if I clipped a rib. With no exit hole I was left with a VERY difficult blood trail and it took me and 3 hunting buddies an hour to find a deer that was dead 10 seconds after I shot him.......scarey.

I don' t know about you guys but after last year I want to see BLOOD!!! I' m talking blood that flows.......not drips. Now I realize that you have to make a good shot to see that kind of blood but I feel like I made that shot last year and didn' t get the red brick road I was looking for.

The WASP JAK-HAMMER did what I wanted it to do. It flew straight and killed the deer I shot at very quickly. Great head and I recommend it highly to anybody with enough power to get a passthrough with it.

I myself have placed priority #1 on penetration this year.........straight flight is a must......but that is true of ANY head. My goal is a passthrough if I make a good shot. It is hard enough getting a deer inside 20 yards of your stand and then making the right moves and perfect shot placement.......the last thing I ever want to do again is feel the fear I felt when I thought I might not be able to find the buck I KNEW I had killed.

I DID my research and picked as small a head as I could find and made a perfect shot and I still almost lost that deer due to a lack of blood to follow. I wish mechanical heads were REQUIRED to list KE minimums on the packages.

They make some really great heads today but I can' t even count how many times I have heard someone say a mechanical didn' t work for them and 99.9% of the time it is because their setup was not powerful enough to utilize that head.

Of course it doesn' t help that they fly so well because that is lure enough to get people to buy them. Combined with some pro shops and sporting goods stores that will sell them to anyone and in fact recommend them to people because they fly so well causes many failures IMO.

RE: Spitfire Problems
 

I emailed NAP about the kinetic energy minimums required for their spitfires and shockwaves awhile back. I believe I received a well thought out and honest reply from their tech. Here' s the reply

We publish a minimum specification for all of our mechanicals of 50 FT/LBS.
Depending on your set up and arrow weight you may be able to use a much
lower KE than this. However that is a personal choice.

Few people realize that broadhead penetration has very little to do with
broadheads. Rather, penetration has almost everything to do with arrow
flight. A well tuned 50 pound bow with arrows that fly without wobble
penetrates better than an 80 pound bow with aberrant arrow flight. Probably
the greatest disadvantage of mechanicals in general is that as a group they
tend to be much more critical of arrow spine than replaceable or fixed
bladed broadheads. For instance, because there is a loss of energy of about
1 to 3 ft/lbs. when a Spitfire contacts a target, and because this energy
loss is directly opposite the direction of travel, an improperly spined
arrow will have an additive effect. Generally an improperly spined arrow
fails to penetrate well regardless of broadhead style because the energy is
partially lost in some direction other than straight forward when the arrow
strikes an animal. A standard broadhead in this scenario would most likely
penetrate and stick in the animal with enough of the shaft inside to lodge
it until the animal does something that causes the shaft to break or
possibly get pulled out during escape. Spitfires along with most other
mechanicals will almost instantly back out because of the additive effect of
the spine related energy loss, reverse energy of opening the blades and the
fact the blades can close easily preventing any anchoring effect. Arrow
flight is especially important on high angle shots. If the arrow is
wobbling back and forth or up and down, then when it hits the target/animal
the energy continues to the side rather than straight forward. On a
mechanical this would have the effect of pivoting the broadhead and reducing
penetration. Keep in mind that if your arrow flight is good then increased
angle has NO effect.

Another thing to consider is momentum. Momentum is often disregarded in
archery because people tend to concentrate on kinetic energy. Let me
explain the difference. Kinetic energy is the impact energy of the
projectile. It is a very good way to determine how efficient your bow
transfers stored energy in the limbs to dynamic energy in the arrow. For
the most part kinetic energy in the 50 ft/lbs. to 60 ft/lbs. range is ample
for taking animals in the deer to elk range. Kinetic energy in the 60
ft/lbs. to 70 ft/lbs. will effectively take any animal in North America.
For example, Chuck Adams took his 1400 pound Kodiak Grizzly Bear with about
65 ft/lbs. of kinetic energy. I believe he used an arrow in the 630 grain
range that traveled about 220 fps. While there are several arrow/speed
combinations that would produce 65 ft/lbs. of kinetic energy, Chuck opted
for a heavier slower arrow because of the momentum. Momentum is the ability
of the projectile to continue in motion. Momentum is a linear function of
mass. The idea is the greater the mass the more resistance is required to
slow or stop the object. Think of it this way if someone were to pitch a
baseball and a bowling ball to a batter, and both balls had the identical
amount of kinetic energy even though one is traveling very fast and the
other is traveling very slow. The batter would be able to hit the baseball
and move it in the opposite direction very easily while the bowling ball
would most likely break the bat. The bowling ball has tremendously greater
momentum and therefore is much more difficult to stop or slow down.

Hope this helps.


Cary J. Pickands
Technical Support Specialist
New Archery Products, Corp.
7500 Industrial Drive
Forest Park, IL 60130
800-323-1279

RE: Spitfire Problems
 

My first year with spitfires, let you know how it turns out.

RE: Spitfire Problems
 

I totally agree with the above..However, a major and I do mean major reason people give as to why the went with mechanicals is that " My field points flew great, but I just couldn' t get the fixed blade heads to group well" . How many times have you heard that one? If you can' t get the fixed blade heads to fly straight it is because your bow is out of tune. Period. IMO most people switch to mechanicals simply because they can' t get their fixed blade heads to fly straight. So instead of tuning the bow or having it tuned, the quick and easy way is to switch to mechanicals thinking their problem is over. The problem is not over. It has only just begun. You are still shooting an untuned bow. Yeah your arrows are grouping better, but the thing is still out of tune and when you shoot a deer that is when the big problem occurs. The mechanicals are not going to penetrate well because they are not flying true.


Here is another big boo boo in my opinion. How many guys are shooting underspined arrows? Based upon what I read here on the BBS pertaining to different peoples setups, a lot of us are shooting underspined arrows. So in addition to the out of tune bow we are adding to the problem with an underspined shaft. No wonder all the posts here pertaining to mech' s.

And the final straw...Momentum. Once again, how many of us are using 300 or 350 grain arrows for hunting? Way too light for me and IMO way too light for you too. Yeah, it' s coming out of the bow at 275fps but if it doesn' t penetrate properly what is the point? So lets see...Untuned bow, underspined shaft, arrow that is too light to carry adequate momentum. Recipe for disaster.

With all that being said, what it comes down to is knowing our equipment. If you don' t know how to tune your bow...Learn. If you don' t know how to select the proper shaft size...Learn. And by all means, don' t get so caught up with arrow speed that you will sacrifice penetration. If the arrow chart lists two or three shaft sizes for you setup, don' t automatically go with the lightest because it shoots the fastest. A heavy shaft is not a bad shaft. Do not take shortcuts.

RE: Spitfire Problems
 

Wow someone hung this bait and allowed the faithful fixed blade crowd the chance to climb on their soap boxes yet again. So I might as well offer my $.02 worth.

It is all about the set-up and preparation.
Knowing your equipment and yourself go a long ways - what you can and can' t do.

Weekend warriors and a few " seasoned veterans" don' t practice enough, maintain their equipment and don' t really make the time or desire to know more about it. Ok I could start to rant further and go into it but it comes down to simple truth or knowing your equipment and ability before entering the field.

RE: Spitfire Problems
 

I too am interested in finding out my KE. I shoot a Hoyt HavocTec, 29" draw length, set on 62 lbs. My arrow setup is as follows: 400 gr. Behman ICS Hunters (cut, but I am not sure how much), with 100 gr. NAP Spitfires. Anyone know what my approx. arrow speed and KE are?

RE: Spitfire Problems
 

Coolbrze, see Atlasman' s post, and go to bowjackson on how to calculate k.e. This way you' ll learn how to do it yourself, and know for the future!!!!!!!!!!!!!!!

RE: Spitfire Problems
 

First, thanks for all the info. As a new member of this site, I' ve learned more about broadhead selection in this single thread than in all my visits to many quality archery shops. You guys are a knowledgeable bunch!

For any of you who are looking to calculate KE, you can download the shaft selector program from www.eastonarchery.com . It includes a nifty KE calculator.

My biggest lesson learned from this discussion? If it ain' t broke don' t fix it! I switched to mechanicals in hopes of extending my range to 30 yards or beyond. Fact is, I' ve never taken a shot beyond 22 or 23 yards, and see no reason to do so now. My fixed heads group fine at those ranges, and their effectiveness has been outstanding.

Thanks again,
Bob

RE: Spitfire Problems
 

i took a nice buck last night with a spitfire 85 i got a pass through at 20 yards
about the blades u often find them closed even though they do open.there is a way to test if they open on the back of the package if you dont beleive me

RE: Spitfire Problems
 

I' ve been using Spitifire 85' s for going on 4 years and I have had no problems other than those cause by my own shooting. Every good and some not so good shots I' ve made have resulted in quick kills and awsome bloodtrails.

I am shooting 63# with a XX78 2314 arrow and am have no problem whatsoever with penetration. My Mathews Conquest Light and the Spitfire' s are a deadly combo.

I have heard hunters who have never shot a Spitfire making statements about how they don' t open at times........IMPOSSIBLE !!!! Take a look at the blade design and it is very obvious that this blade is not going to stay closed when impacting a deer in the vitals IMO.

RE: Spitfire Problems
 

Here ya go Rico,

I could post dozens more pics of me with deer that fell prey to the spitfire but I guess I just have the perfect setup for them;)

RE: Spitfire Problems
 

Easton has an arrow selection utility program that will also calculate your kinetic energy....hers a link to it

http://www.eastonarchery.com/downloa...lector2003.zip

and this is the webpage its on...
http://www.eastonarchery.com/downloads

RE: Spitfire Problems
 

Well, if he' s shooting a 2413 unibushing with 3 vanes and a 100 grain point his arrow weighs closer to 500 grain, something like 492. Anyway, at 230 fps that heavy arrow is up to 58 foot pounds, which according to everything I' ve read should work. That said, I don' t like mechanicals. Stick with the Thunderheads.

RE: Spitfire Problems
 

I have been shooting spitfires for about 6 years and I can give you a list of animals I have taken. From elk, deer, axis, and many of them. Over the last 6 years I have lost 2 animals. NOT the broadheads fault though. They were shots that hit to far back.

I know my equipment, and work with it year round. What I see to often is lack of practice with broadheads. This is when you should practice even more. There' s alot of good info on this post and everything is important. However, things are magnified even worse when the shoot is poorly placed. Let' s be a little more critical of ourselves and what we' ve done before we blame equipment on OUR screwups!!!

J. Shoot

RE: Spitfire Problems
 

As stated by others you need to have a well tuned bow and the KE to use mechs, I love my spitfires and until they fail me I will continue to use them. I agree with everyone who says the blades didn' t open, I challenge anyone to shoot them through a fresh deer hide into a backstop and not find them open. They do close after they either are backed/pulled out of a deer or they blow through.

RE: Spitfire Problems
 

I have used NAP Shockwaves but never Spitfires..... The reason - my lack of belief in them. It seeems as though80% of the stories I have heard about poor performance with a mechanical were from Spitfires.... NAP makes great products but I dont think the Spitfire is so great. Yes it may be sharp, and durable.... But the Shockwave and Spitfire are a lot better...... I have had pass throghs with shockwaves at steep angles on HEAVY deer (200+) I read a story recently where an outfitter specifically says " If you hunt here - no Spitfires" - after that, and reading your post, I am thinking NAP should take a HARD look at that head and perhaps make it very clear that it needs a ton of KE to be effective.....