Mechanical Broadheads

What makes mechanical broadheads different

The blades move. That's the whole difference, and it drives every spec below. In flight, a mechanical's blades sit folded close to the ferrule (the center body), held in place by a band, a collar or a clip. On impact they swing out to the full cut. For the basics every broadhead shares (inserts, threads, grain weights, tuning against field points), see the main broadheads page.

The table on this page lists expandable (mechanical) broadheads, as the maker states the type, with the widest cut first. Values come from the maker, or from the Amazon listing where the maker is silent (the table marks listing values); a dash means neither states it.

What to look at when you pick mechanical broadheads

Here's what actually changes from one mechanical to the next, in the order I'd check it. Energy first, because it decides whether the rest matters.

Check your kinetic energy against the maker's floor

Kinetic energy (KE) is what your arrow carries downrange, in foot-pounds. Mechanical makers set floors for it. G5's FAQ recommends at least 40 ft-lb for its expandable heads on whitetail-size game. New Archery Products recommends about 50 ft-lb for deer-size game and about 55 for bigger animals. Two makers, two numbers, which is why you read the one on the package you're buying.

Why a floor at all? GOHUNT's breakdown explains that deploying the blades uses some of the arrow's energy and can reduce penetration. Grand View Outdoors puts the cost of opening at up to 15 ft-lb for some expandables. That's energy a fixed head would keep for the cut.

Quick math, using New Archery Products' formula: arrow weight in grains × speed × speed ÷ 450,240.

• A 350-grain arrow at 250 FPS (feet per second): 350 × 250 × 250 ÷ 450,240 = about 49 ft-lb
• The same arrow at 290 FPS: about 65 ft-lb

So a light arrow from a slower bow can land just under one maker's deer number and well over the other's. On paper the difference is a few foot-pounds. In practice it's the difference between "fine" and "read the fine print again." (Use your arrow's measured speed, not a guess. Walt's guesses run like the gas gauge on his truck: optimistic below a quarter tank.)

Draw weight is the other half. Petersen's Hunting suggests bowhunters pulling under 50 lb test that the blades actually open on impact, and GOHUNT links mechanicals to bows above roughly 55 lb, where the energy cost is usually manageable on most big game. Interestingly, New Archery Products says its heads don't need a minimum speed to open; it reports them opening into foam from a 5-lb bow. Opening isn't the hard part. Driving through after opening is.

Opened cutting diameter is the number on the box

For a mechanical, cutting diameter means the width with the blades fully open. Petersen's Hunting calls 1-1/2 to 2 inches standard, with some heads going past 2. GOHUNT gives a common range of about 1.5 to 2.25 inches.

Wider takes more energy to push through, so the cut and the KE check go together. If your quick math sits near the maker's floor, a smaller opened cut is the conservative choice. If you have energy to spare, the wider heads make sense.

States measure this number too. Illinois, for one, allows expandable heads but requires a minimum of 7/8 inch when fully opened. The rule is written about the open width, so that's the number to know.

Blade count: two is common, three and four exist

The "Blades" column counts the blades that open. GOHUNT says mechanicals are most often 2 or 3 blades, though 4-blade versions exist. Each extra blade is one more edge that has to swing out and cut, which is one more place energy goes. Read the blade count next to the opened cut; the table puts both columns side by side.

Front-deploy or rear-deploy changes how the blades open

Petersen's Hunting sorts mechanicals two ways. Front-deploying heads open from the front of the ferrule, with the blades swinging back as the head goes in. Rear-deploying heads open from the back. GOHUNT describes the same split: some blades open rearward, others swing from forward to rear. Makers don't always name the style in the specs, so look at the product photos of the open head.

Blade retention is the part to inspect every time

Something has to hold the blades shut in your quiver and in flight. Petersen's Hunting lists an O-ring, a collar or a tension device, and notes that retention failures can happen. New Archery Products uses internal clips that press on the blades. Other designs skip bands entirely.

Whatever holds them, check it before every hunt. A band that's cracked, a collar that's missing or a blade that flops when you tip the arrow means that head stays in the box. Keep a few spare bands or collars in the pack if your heads use them (they weigh less than the extra headlamps Danny packs).

100 grain mechanical broadheads match most tuned arrows

Weight is in grains. Archery 360 calls 100 grains par and says most spine charts assume a 100-grain point, which is why 100 grain mechanical broadheads are the most common search in this category. If your arrows were built and tuned with 100-grain field points, a 100-grain mechanical drops in without changing the spine math. Go heavier and Archery 360 notes the front weight makes the shaft act weaker, so check the chart again. The 100 grain broadheads page lists all types at that weight.

Blade thickness and pack count are the quiet columns

Blade thickness is the stock of each blade in thousandths of an inch, when the maker or the listing states it; many don't. Pack count matters more than it looks for this type. Bowhunter's prep guide suggests one mechanical head per animal and replacing any head that shows wear or a blade problem during practice. A three-pack goes faster than you'd think.

Who mechanical broadheads suit

Mechanicals make the most sense for a compound shooter with energy to spare who wants broadhead flight that stays close to field points. That's most of what GOHUNT and Petersen's Hunting describe: forgiving flight, a quieter arrow and a wide cut.

They also suit the hunter who shoots without blind mesh in the way and practices with the exact heads they'll hunt with. Petersen's Hunting makes that point in its conclusion: the type matters less than confidence in the head and practice with it. If that sounds like you, the deciding questions are energy, cut and retention, in that order.

How expandable broadheads fly and sound

Folded blades are the reason mechanicals fly the way they do. Petersen's Hunting says they fly like field points and are quieter in flight than vented fixed heads. GOHUNT calls them more forgiving, often matching field-point accuracy out of the box and handling wind and form problems better.

That changes the arrow you need. Archery 360's compound arrow guide notes that mechanical heads need less steering than fixed ones, so smaller fletching works. GOHUNT's author also leans on mechanicals for longer shots and higher wind, where a fixed head's blades act more like wings.

"Flies like a field point" is a claim you still check. TenPoint's FAQ points out that a broadhead's shape differs from a field point's even at the same weight, so you may need a small sight adjustment. Bowhunter's author found heads labeled field-point accurate hitting low at 35 yards.

Setting up mechanical broadheads before the season

1. Weigh and spin. Weigh each head in grains and spin it on its arrow; Bowhunter's guide says wobble means a bad head or a shaft end that isn't square.
2. Check retention. Band, collar or clip in place on every head, blades closed snug.
3. Shoot them, not just field points. Bowhunter suggests the last two weeks before the season with broadheads only, out to your longest shot.
4. Prove they open. New Archery Products' trick: tape paper to the back of the target, shoot through, and read the hole.
5. Paper tune if penetration looks poor. New Archery Products says weak penetration usually traces to an arrow that whips or porpoises in flight.
6. Use fresh heads for the hunt. Practice heads are practice heads.

Mechanical broadheads and ground blind mesh

New Archery Products is direct about this one. It doesn't recommend shooting its expandable heads through mesh, because anything touching the blades can open them in flight, and shooting any broadhead through mesh may move your point of impact. If you hunt from a pop-up blind, open the window you'll shoot from before you sit.

Yes, that means sitting next to an open window in November. Bring the good hat, and tie the flap back so it can't swing into the shot lane. A mesh panel looks like nothing at all, and to a folded blade it's a reason to open early.

Mechanicals from a crossbow

Crossbows are a different speed class. G5 recommends only the crossbow version of its expandable heads on a crossbow, regardless of the speed rating on the bow version. Ratings, bolt weights and what crossbow makers recommend are on the crossbow broadheads page.

Handle folded blades like open ones

Folded blades are still sharp. Keep mechanical heads in a covered quiver or case, thread them on with a broadhead wrench, and never test a blade's swing with a finger. Oregon's wildlife department says plainly to make sure broadheads are safely covered.

Some states limit expandable heads or set their own width rules for them, so check your state wildlife agency before the season.

Who should skip mechanical broadheads

Skip this type if your quick math lands under the maker's energy floor and you can't raise it. A heavier arrow or a different head type will serve you better than hoping. Skip it if you shoot through blind mesh and don't want to change that habit. And skip it if moving parts bother you; the Union Sportsmen's Alliance notes plainly that expandables can fail because they have moving parts. The fixed blade broadheads page is the other road.

Everyone else: run the numbers, check the bands, and write the KE in the logbook next to the yardage.