Mechanical vs Fixed Blade Broadheads – Cut The Crap, Here’s The Truth

One of the most contentious topics debated in hunting camps is the ideal broadhead for hunting. The argument of mechanical vs fixed blade broadheads is common among hunters and has divided them for years. We decided to finally find out which is better, and the results were very enlightening!

The conversation among crossbow and compound bow enthusiasts when choosing between fixed and expandable broadheads is like the Chevy versus Ford discussion. Every broadhead has pros and cons that can be definitively measured but regardless of this, most bowhunters argue based on a personal preference that’s rarely based in science.

It’s a difficult choice to be sure, and ultimately it’s still up to you, but before squeezing the trigger to release your shot at the target, why not dive a little deeper and consider how your broadhead choice could affect your hunt?

Overview of Mechanical and Fixed Blade Broadheads

Mechanical Broadheads

Some people detest mechanical broadheads, while others love them. Either way, you have to admit that an expandable blade broadhead is quite innovative. They were invented with two thoughts in mind, narrower-profile designs for greater precision and predictability in-flight, and expandable blades for a wider cut and greater blood loss.

Prior to contacting the target, a mechanical broadhead has a much slimmer look than fixed blade broadheads, not quite as slim as field points or bullet points, but still quite narrow.

Upon impact, the mechanism is triggered which causes the blades to expand, creating a much wider wound than any field or bullet point and delivering significant damage as it rips through the target.

Several designs exist in the market, though the overall concept is the same. When a single head passes through an animal, it is intended to give a larger blood trail and a more reliable harvest.

Mechanical Broadhead Pros

• They have a close-to-field point precision, even at high speeds and over long distances, particularly when compared to a bow/xbow shooting a fixed blade broadhead that hasn’t been properly tuned
• Require less tuning to optimize your shots
• They have the greatest potential for high blood loss of any point, as once opened they are considerably wider than other heads
• Blades are often replaceable

Mechanical Broadhead Cons

• They are not 100% reliable and can fail trigger on impact, or trigger early in flight, causing you to miss
• They are more prone to damage and less durable than fixed blades
• The expansion of the blades slows down arrow momentum, resulting in less penetration
• Do not perform as well as fixed broadheads when shooting at wide angles
• Can create more noise than other arrow points when fired

Fixed Blade Broadheads

This is the original, tried-and-true type of broadhead, the one that marked the beginning of it all. The first arrowheads and crossbow points were fixed blade broadheads.

Early fixed blade broadheads were made from a single piece of molded metal. This design remains very effective in today’s market, but some modern options include replaceable blades and are made from multiple pieces.

Fixed blade broadheads stay in the same position at all times. You can rely on them doing exactly what they’re supposed to do given they don’t feature any adjustment screws or moving parts (other than to replace blades).

Fixed blade broadheads are designed for raw devastation. All the energy transferred upon contact is intended to penetrate the skin of an animal and deliver damage for a kill shot. Nothing can get in their way.

Although most fixed blade broadheads are relatively large, they do come in a number of sizes and shapes, from smaller slicing diameter heads to help in arrow flight (such as chisel points) to the often-seen large, nasty ones designed for rapid blood loss.

Their main downside is precision, particularly over longer distances or at higher speeds. The wider-set design during flight can cause inaccuracy if the bow isn’t tuned correctly to the shooter So if you’re not prepared to practice and tune your gear, you may struggle with fixed blades.

Fixed Blade Broadhead Pros

• With no moving parts, fixed broadheads are fail-proof
• These broadheads are super durable and can be re-used with periodic sharpening or blade replacement
• Fixed broadheads offer unparalleled penetration
• Are highly effective from almost any angle
• Their simple design means they are the most affordable option for broadheads
• Unless they are a replaceable blade design and not tightened properly, they don’t add any other source of noise when shot and so are silent and very deadly

Fixed Blade Broadhead Cons

• The cutting diameter limits their performance in-flight
• Will probably have arrow flight issues.
• Statistically shown to have slightly less effectiveness than mechanical broadheads, though it’s debatable as the numbers don’t seem to capture proper tuning

Mechanical vs Fixed Broadheads – The Factors That Actually Matter

The science of shooting an arrow or bolt should be predictable, at least in theory. Unfortunately, there are many, many variables that make the practical results difficult to interpret.

Even simple differences like the wind speed or direction between shots, the ratio of flesh to bone at the point of entry, the reaction time of the target, or the ability for the shooter to adjust to different arrow or bolt setups are very hard to correct for in a truly scientific way.

Despite the difficulty, enough data is available to make reasonably safe and reliable conclusions about the performance of mechanical vs fixed blade broadheads. Here’s a quick run-down of what actually matters.

Penetration

Penetration is the counterweight to a wide cut. The overall wound may be narrower, but if you completely pass through an animal, it’s going to bleed and it’s probably going to be a kill shot.

In simple terms, penetration is broadly a function of speed, weight, sharpness and stiffness. All are impacted by your broadhead selection.

Weight is a choice that can easily be managed regardless of broadhead, as most options provide ranges between 75 and 200-grain points. In general, heavier heads will deliver greater penetration, just be careful to balance out the rest of your arrow or bolt setup to compensate for a heavier broadhead.

Similarly, sharpness can be dealt with by sharpening or replacing your blades regularly. Blades that are sharpened to a razor-like edge perform better on penetration tests. And I truly mean razor-like, you should actually be able to shave your arm hairs with your broadhead.

Speed is the first factor that creates some differentiation between broadhead types. Although it creates a wider cut, the mechanism which opens the blades on a mechanical broadhead effectively acts like brakes when it comes to penetration.

As the blades open, the energy that was previously driving your projectile forward is transferred sideways to widen the wound and cut through more flesh. This reduces forward momentum dramatically and negatively impacts penetration.

Fixed blades don’t experience this same issue. All of the energy continues to drive the blades forwards for maximum penetration.

The contrast is definitely less of an issue with today’s high-speed, high-energy bows and crossbows, but the fact is you are much less likely to see full pass-throughs with mechanicals than fixed-blades, and this is a big part of the argument among hunters.

The final factor is stiffness. This is another area that widens the divide between the two main broadhead types. Fixed blade broadheads are very stiff, particularly single-piece designs. Their rigidity transfers all the energy into the animal upon impact, improving penetration.

This contrasts with mechanicals, whose moving parts cushion some of the energy. Although similar, the concept here is slightly different to the drag they create when opening which affects speed. Here, we are talking about a concept in physics called “impulse”, which measures force over time and directly relates to change in momentum.

Stiff fixed-blade broadheads with cut-on-impact tips apply their force almost instantly to a surface, minimizing impulse and the corresponding negative impact on momentum.

Mechanical broadheads spread the force at impact out over time, as the mechanism to open the blades increases the time the force is being transferred to the target. The long and short of it here is that the opening of mechanical broadheads reduces momentum relative to fixed-blades and therefore reduces penetration.

If you prefer mechanical broadheads, you need to compensate for the lack of penetrating power. Luckily there are a few simple things you can do:

• Sharpen your broadheads regularly
• Use a high-quality broadhead that is resistant to breakage and damage
• Choose a broadhead with a very smooth, frictionless finish
• Increase the weight of your overall arrow or bolt setup
• Ensure the spine of your shaft is high (very rigid shaft)
• Use broadheads with cut-on-impact designs
• Ensure your arrows or bolts have a perfectly balanced spin
• Tune your hunting rig for perfect flight performance
• Increase the draw length of your bow or crossbow

These factors will maximize penetration for all broadheads but are even more important to apply when using mechanicals.

Surface Area

It’s basic aerodynamics. Less surface area means less chance for the air to act upon that surface and redirect your shot. Without tuning, the larger surface area of fixed blades will lead to flight with less precision.

The differences become more noticeable the longer the arrow or bolt remains in flight before hitting the target. There is an often-quoted threshold of around 265 feet/second, but this is actually not very informative.

What’s missing here is distance. A limit of 265 fps might be true at 100+ yards but is definitely not true at 40. The difference between narrower mechanical broadheads and fixed blades becomes more obvious at about 50-60 yards, a distance that would be considered reasonably long for hunting.

Sure, if you own a premium Excalibur crossbow that shoots at 400+fps, you might expect to shoot 60+ yards with precision and this analysis might actually matter to you, but for most hunters, they won’t really notice the difference at normal shot distances.

There is no doubt that closed-in-flight mechanical broadheads fly through the air with much less aerodynamic drag than wide-profile fixed blades, but the practical performance of narrow or wide broadheads at typical bowhunting ranges is actually negligible.

It’s a factor, science can prove this, but not one that always matters. Great hunting skills in other areas that allow you to get close to your target can easily negate this issue.

That being said, mechanical broadheads can be shot over longer distances with more accuracy, so they do ultimately provide more options, particularly when hunting skittish prey or if trying to take full advantage of high-speed bows and crossbows.

Durability

In the short term, durability is unlikely to cause a problem, but over the long term, it definitely matters. The less time you need to spend maintaining or replacing your gear, the less it will cost you and the more time you can spend enjoying the sport.

One of the upsides of fixed heads is their strength. Their design, particularly the single-piece options, are intended to be ultra-rigid, reinforcing the entire length of the head.

It’s a fundamental engineering principle. More parts and complexity mean more potential points of failure and therefore more chance of failure. Even the designs with replaceable blades, which adds some complexity, are still very stiff and robust. A movable mechanism of the same size and material is nearly always weaker or more prone to failure than an immovable one.

This isn’t to say that a poor quality fixed broadhead is better than a top-notch mechanical one, but the simplicity of fixed blades definitely works in their favor in the durability department.

When contrasting a premium mechanical broadhead and a premium fixed-blade, the fixed option is undoubtedly more robust and has a higher chance of lasting a long time.

The only potential downside here is that longer-lasting heads do mean more sharpening. A replaceable blade option solves this problem, but if you are going for a single-piece design, make sure you choose a high-quality material that stays sharp longer and sharpens well. Carbon steel or stainless steel is your best bet for broadhead materials.

Spin Testing and Arrow Setup

We touched on aerodynamics when talking about surface area. The other big factor in aerodynamics is spin. You may see some broadheads claiming they have been rigorously spin-tested, and this is a good thing.

What they are testing is that the shape and design of the broadhead produces a balanced spin in-flight. Any imbalance, no matter how small, can be significantly magnified when shot over a distance. So definitely look for a spin-tested broadhead. You can even do your own spin testing if you’re concerned.

Arrow/bolt setup is your next target area. Mechanical broadheads will perform similarly to field points at typically hunting distances but with the wrong arrow or bolt setup the larger profile of fixed blade broadheads will result in underperformance.

Fortunately, this can be easily corrected. Assuming spin testing shows no issues, here are the ways to adjust your set to support larger profile fixed blade broadheads:

• Increase your vane length to compensate for the additional steer caused by the larger surface area of fixed blades. 4-5 inch vanes for large broadheads is not uncommon
• Switch to feathers over vanes, as they offer superior flight performance. Using the same length feathers as the vanes you previously had should show a noticeable improvement
• Switch to helical feathers or vanes if you aren’t already using them. One potential downside is that helical fletching can struggle in some arrow rests, so switch to a drop-away arrow rest if you’re noticing any fletching contact when shot
• Move your front-of-center (FOC) balance point further forward to increase the steering influence of the fletching. You can achieve this by using heavier grain broadheads or longer shafts
• Tune your crossbow or bow by testing your shots with broadheads against your shots with field points (you should do this regardless of what broadhead you choose). Adjust your rig to compensate for any inaccuracy, tweaking your arrow rest or sights accordingly

It is worth noting that over time, your shaft or heads can warp and may need to be spin tested and corrected if they have come out of alignment. This can be done at home by simply rolling the shaft along a table or desk and observing any imperfections. You can also get a proper arrow spinner very cheaply.

One last point is spin-speed. The centrifugal forces from a rapidly rotating arrow or bolt may inadvertently whip open the blades of a mechanical broadhead mid-flight. This problem is magnified at higher speeds and longer distances, with more arrow spins increasing the chances of the blade opening prematurely.

If you prefer mechanical broadheads and are facing this problem, you can try using shorter vanes/arrows or straight fletching to reduce spin.

Quartering Shots

This is an area where fixed broadheads have an edge, pun intended! It’s not that mechanicals perform poorly on angled hits, particularly quality models, but they simply don’t perform as well as fixed blades.

The threshold seems to be somewhere around 40 degrees. If the animal is facing you at a narrower angle than this, you should be fine regardless of your broadhead.

At wider angles, the impact can cause one of the mechanical blades to open prior to the others, creating a force that deflects the arrow or bolts away from the animal, particularly if it hits a bony area.

The same risk is not present for a fixed-blade broadhead. With no moving parts, all the kinetic energy continues forward. Deflections are still possible with fixed blades, they’re just rarer.

Again, if you love your mechanical blade broadheads there are a few ways to compensate for this increased risk of deflection:

• Use a heavier arrow or bolt setup as the energy required to deflect a bigger weight is obviously also bigger. 500+ grain arrangements will significantly reduce the risk
• Using a higher spined (more rigid) shaft will reduce the likelihood of deflection
• Select mechanical broadheads with cut-on-contact tips that penetrate your prey a reasonable depth before the blade expanding mechanism is triggered
• If possible, exercise patience or reposition yourself to get a tighter angled shot and reduce your risk

Mechanical vs Fixed Blade Broadheads – The Bottom Line

All this information has been available for a long time, there’s nothing really new here. In fact, the data available to prove the point is increasing day by day, as more and more semi-professional and professional hunters carry out their own testing following a proper scientific methodology.

It seems that no matter what is said or demonstrated or proved, the debate on fixed and mechanical broadhead blades will carry on forever and continue to remain contentious. Just remember, it’s about personal preference, so your mantra when this topic comes up should be “each to their own”.

What is important is that a fixed blade broadhead, particularly when shooting at distances over 60 yards or very high speeds in excess of 300fps, will require precision tuning to have the same level of accuracy as a mechanical head. This takes time, but it will put everything on a level playing field.

Similarly, if you’d like to avoid all the tuning or prefer mechanical broadheads, make sure you go for a high-quality model, preferably one with a cut-on-contact blade to improve performance in quartered shots and opt for a higher weight in your overall arrow or bolt setup.

Either way, maintain your broadheads regularly and be sure to test the rest of your setup before you blame the broadhead and contribute to the fallacy around each broadhead type’s pros and cons.

Now that we’ve got through that, check out our list of the best broadheads and take them out for a spin!