This was a fun read. its kinda making me rethink these g5 montecs i just bought. Source http://www.alaskabowhunting.com/Ashby-Broadhead-Performance-W15.aspx ------------------------------------------------------------------- BROADHEAD PERFORMANCE BY Dr. Ed Ashby Most often little attention is paid to what broadhead one selects to hunt with. Often the choice is predicated on what the local sporting goods store has in stock, what one's hunting buddies use, what worked on Uncle Joe's deer last year, or on that tried and true axiom "If it cost more it must be better". Volumes of data on terminal ballistics (what happens from the moment of impact) have been written for every conceivable rifle / bullet combination in existence. Virtually no such information exist for archery equipment. In the summer of 1985, I had the unique opportunity to conduct a field research project to evaluate, at least on a limited basis, the effectiveness of various types of broadheads. The project was conducted at Mkuzi Game Reserve in the Provence of Natal, Republic od South Africa. Tony Tomkinson, Chief Ranger at Mkuzi, was the moving force behind the research. He has also been the person primarily responsible for the opening of Natal to legalized bowhunting. Tony deserves the thanks of all archers for his dedication and Herculean efforts towards the opening of Africa to bowhunters. THE PLAN We set out to evaluate the effectiveness of as many types of broadheads as possible on a wide variety of game from the size of bushbuck to zebra. We had hoped to evaluate the effectiveness of the bow against cape buffalo, but no buffalo were listed for herd reduction and no animals were available for testing. Still, the variety of animals tested are most applicable to selection of broadheads for North American game. The animals in the test included impala and bushbuck (average weight from 106 to 143 pounds), warthogs (154 - 220 pounds), nyala (198 - 299 pounds), wildebeest (473 - 550 pounds), and the zebra (700 - 1000 pounds). Some testing was also conducted on giraffe and white rhino, but the data from these animals was not included in the performance analysis. The size of these animals places them outside the practical realm for all but the very most experienced of archers. I found that hunting the rhino, besides experience and skill, also required nerves of steel and the ability to run like hell! THE EQUIPMENT All testing to evaluate broadhead performance was done with heavy draw weight bows. This was done to negate bow weight as a limiting factor. Tony used an 80# Martin Warthog compound for all his shooting, and I used a 94# longbow. The average total mass of the arrows used with the longbow was 698.5 grains, the average velocity was 182 FPS. The mass and velocity, of necessity, varied with the different broadheads. Tony's compound was not available to me to chronograph prior to the trip, and the average velocity is unknown, but I would expect it to be comparable. Thirty two varieties of broadheads were tested. These included most popular fixed and replaceable blade heads, and a number of limited production semi-custom heads. METHODS The data was accumulated using two different sources. One was animals hunted and taken solely with a bow. This method was employed to the maximum extent possible. Where more detailed evaluation of a particular shot was desired, the animal was taken with a rifle (being careful not to damage any tissue even remotely near the site for the test shot) then positioned and shot with the arrow. These "simulated" test shots were taken immediately to minimize the effects of tissue change. Each shot was evaluated by wound channel examination and by dissection. All field evaluations were tape recorded and later transferred to written shot evaluation forms. Where field evaluation was not complete enough, such as shots into the spine, the animal was returned to the slaughter house for dissection and detailed shot evaluation. The data was transferred to a computer data base program for analysis. Shots taken on animals previously culled with a rifle were rated as lethal if: (1) a major nerve center was penetrated, (2) a major blood vessel was severed, (3) the thorax was penetrated and a vital organ hit, (4) a major visceral organ was hit, ie: kidney, liver, etc. All usable meat from animals taken was salvaged. Non-usable parts were used in the predator feeding program at Mkuzi. THE DATA Data from 154 shot records was included in the data base for evaluation of broadhead performance. The accompanying tables and graphs present a representation of a small portion of the data. Some of the questions that we proposed to address were: (1) what are the most lethal shot angles; (2) what shot angles offer the least chance of a lethal hit; (3) which style of head gives the greatest portion of lethal hits on the most difficult shot angles; (4) is there a significant difference in penetration among the types of heads and, if so, which penetrates best when soft (muscle, connective tissue, etc,) and hard (bone) tissue is hit; and (5) would a restriction on what types of heads could be used on what class of animal be appropriate. THE ANALYSIS Any analysis based upon such a limited number of test reports certainly is open to criticism. This study is, however, the most extensive uniform methodology analysis of broadhead performance ever performed to date on actual game animals. The results, and most definitely my conclusions from those results, will most assuredly be controversial. The analysis itself, however, was performed as uniformly and unbiasedly as possible. One of the striking features noted during the testing was that a large number of the broadheads tested were very fragile, often bending or breaking whether bone was hit or not. Table I and Graph I reflect an evaluation of the different types of broadheads and the percentage damaged during testing. The rigid 2 blade (or more accurately, single blade with two cutting edges) broadheads proved to be significantly more resistant to damage than either the rigid multiblades or the replaceable blade type of broadheads. Table II and Graph II are the result of the evaluation of the probability of a hit being lethal based upon the hit location. Hits from directly in front, into the brisket, and shots from a forward quartering angle that hit back of the shoulder blade (to differentiate from shots taken into the very tough neck-shoulder junction area) were 100% lethal, but this was based upon a very limited number of shots. There were 25 shots quartering from the rear forward, with 24 of these being lethal hits. It is of little surprise that this shot is generally regarded by experienced bowhunters as the very best. Not only does it position the hunter so that he may move freely to position for the shot, but also gives a great probability of a quickly lethal hit. It is somewhat disturbing that almost 30% of the broadside shots into the chest-shoulder area were non-lethal. This has long been considered the "classic" shot. The rump hit proved fatal just over half the time. Its lethality proved dependent on (1) whether the femur is hit, (2) whether the head can break the femur to reach the femoral artery and iliac vessels just deep of the femur, or (3) whether the hit is medial to the femur and penetration is deep enough to reach the vessels (significant penetration is required on a large animal such as a zebra). As had been expected from past experiences, the toughest shot on which to make a kill was into the area of the neck-shoulder junction. Table III and Graphs III - VI reflect a further analysis of broadhead shots when single blade heads are compared to multiblade heads. It addresses four scenarios: (1) the percent of hits that are lethal when single blade heads are compared to all multiblades, regardless of hit location; (2) when only shots that hit heavy shoulder blades are considered; (3) when a rib is hit on entrance; and (4) when the hit is in the area of the neck-shoulder junction. Among the 16 scapula hits with single blade broadheads, 12 penetrated the scapula (shoulder blade) and rib cage to enter the thorax to be lethal hits. Four failed to reach the thorax: an Anderson 245 shot as a single blade (penetration was 3/8" into the scapula); a Black Diamond which, according to the field notes "bent into a long curve" on impact with a zebra scapula; a Premium I which hit a warthog scapula and "bent at a 90 degree angle, arrow deflected, head destroyed"; and a Grizzly which penetrated the thickest part of a zebra scapula and a rib, but did not enter the thorax sufficiently to be lethal. Only three of the three blade heads hit a scapula: 2 Rocky Mountain Razors (one on a zebra, one on a wildebeest) and a Bodkin (zebra). None penetrated the scapula. Among the 4, 5, and 6 blade heads, there were 8 hits on the scapula. Only two of these penetrated the bone; an Interceptor which penetrated a zebra scapula, and a Kolpin 6 used on a warthog. The Kolpin 6 achieved 10" of penetration, but most of the blades (5 of 6) were sheared off and left in the scapula. If the analysis of the effect of hitting bone on entrance is carried one step further, in order to see the effect of hitting a rib on entrance, all hits with single blade heads were lethal (100%). They averaged........... ------------------------------------------------------------------- This is only a third of the essay. the whole thing really is interesting. If you want to read the full study. the source is posted at top and bottom of page. they also cover blood trails, and many other factors. Source http://www.alaskabowhunting.com/Ashby-Broadhead-Performance-W15.aspx
