Cam Feel Decides More Than the Let-Off Number Does

Fletchwise guides are independent and hype-free – we are not sponsored by any bow brand and we do not chase spec-sheet marketing.

Where a recurve or longbow stores energy purely by bending its limbs, a compound bow adds a mechanical advantage. Each limb tip carries a cam – an oval pulley – and a system of strings and cables runs between them. As you draw, the cams rotate and reach a point where they “roll over,” dropping the holding weight dramatically. This is called let-off. A 70 lb bow with 85% let-off means you pull a peak of 70 lbs, but hold only about 10-11 lbs at full draw, so you can aim longer without shaking.

That efficiency translates into more stored energy and faster arrows from a shorter, more compact bow – ideal for hunting from a treestand or blind, and for the repeatable accuracy competitive target archers need.

Every spec sheet leads with a speed rating, and every speed rating is measured the same way: IBO standard is 70 lb draw weight, a 30" draw length, and a 350-grain arrow (5 grains per pound) – with no accessories on the bow. That is a lab test, not a hunting setup, and almost nobody actually shoots those numbers.

Change any one of those conditions and speed drops. Change all of them the way a real hunter does – a shorter draw length, a lower draw weight, a heavier hunting arrow for penetration, a peep sight, a D-loop, and string silencers – and the losses stack:

What changes from the IBO test	Typical effect on speed
Shorter draw length than 30"	Roughly 10 fps per inch under 30"
Lower draw weight than 70 lb	A meaningful chunk of speed – most hunters run 50-65 lb, not 70
Heavier hunting arrow than 5 gr/lb	Roughly 1-2 fps lost per extra 5 grains of arrow weight
Peep sight, D-loop, string silencers	About 10 fps combined – string weight the IBO test does not carry
Rated 330-360 fps IBO, real-world result	Most hunters land around 270-310 fps

None of this means the bow is defective or the manufacturer lied – IBO is a published, standardised test, and every brand uses the same one, so the number is at least comparable between bows. The mistake is comparing that lab number to what you will feel at your own draw length with your own hunting arrow, and picking a bow (or a heavier draw weight than you can hold smoothly) chasing a figure you were never going to shoot. Two bows rated 10 fps apart on the shelf will usually feel identical once both are set up for a real hunter – the arrow and broadhead guide covers the other half of this: arrow weight and front-of-center do more for terminal performance than a faster bow does.

Two bows can both advertise 80% let-off and feel completely different at full draw, because let-off is a single number and the draw force curve – how weight builds and releases across the whole stroke, not just at the end – is a shape. The cam design decides that shape, and it is rarely on the spec sheet at all.

• Single cam (one elliptical power cam driving a round idler wheel): simplest to keep in time, so it needs the least tuning maintenance. The draw force ramps up quickly through the stroke.
• Binary cam (both cams sync to each other rather than to the limbs): keeps nock travel level through the shot, which tends to help arrow flight and forgiveness, at the cost of a system that is fussier to keep synchronized over time.
• Soft vs. hard cam profile, independent of the cam type: a soft cam eases into the back wall over the last couple of inches and is more forgiving on form; a hard cam peaks quickly for more speed and more let-off, but you arrive at the wall abruptly with almost no transition.

The practical takeaway: draw the bow before you buy it, and pay attention to how it feels through the middle of the stroke and into the wall, not just the number printed under "let-off." A soft-cam 70% let-off bow can feel steadier than a hard-cam 85% bow that snaps into a wall you were not ready for.

The peak force needed to draw the bow, in pounds. Most adult hunting bows run 40-70 lbs; many states require a minimum (often around 40 lbs) for big game. Start lower than you think – good form beats raw poundage, and a bow you can draw smoothly every time beats one you have to muscle up in cold weather with heavy clothing on.

The distance the string travels to full draw, set to your body. A compound only shoots well at your exact draw length, so this must be measured and set correctly – it is the single most important fit spec, and it is also the one that most silently costs you the fps you saw on the box.

The percentage of draw weight the cams remove at full draw, usually 75-90%. Higher let-off is easier to hold – but as covered above, it only tells you the end point, not the shape of the draw that gets you there.

The distance between the cam axles. Shorter bows (28-32″) are maneuverable for hunting; longer bows (33″+) are steadier for target work. If you are also thinking about how the bow travels, the bow case guide covers sizing a case around this measurement.

The distance from the string to the grip at rest. Lower brace height = faster but less forgiving; higher = more forgiving and beginner-friendly.

Spec	What it is	How to choose
Draw weight	Peak pull force, in lbs	40-50 to start; 50-70 for big-game hunting
Draw length	String travel to full draw, set to your body	Must be measured to you – the #1 fit spec
Let-off	Weight the cams remove at full draw	75-90%; check the draw feel too, not just the number
Axle-to-axle	Distance between the cam axles	28-32″ hunting; 33″+ target
Brace height	String-to-grip distance at rest	Higher = more forgiving for beginners

Compounds suit almost everyone: hunters who want power and a steady hold, target archers who want repeatable accuracy, and beginners who benefit from let-off and easy-to-add sights and rests. If you specifically want the simplicity and challenge of traditional shooting, a recurve or longbow may suit you better – see how the styles compare before you decide, or read the direct recurve vs compound comparison. If you already own a crossbow or are cross-shopping one, crossbow vs compound covers the practical differences in draw cycle, cocking effort and hunting regulations.

Two questions come up before almost anything else in a first bow purchase, and neither one is really about specs.

Cost: A capable compound bow starts around $250-500 – that tier will draw, hold and put an arrow through a deer as reliably as anything more expensive at normal bowhunting range. What the next few hundred dollars buys is not more killing power: it is a CNC-machined riser instead of a cast one (tighter tolerance, less flex under draw, no risk of the internal casting voids a cast riser can hide), cams that hold their timing longer between tune-ups, and a quieter, smoother shot cycle. None of that changes what the bow can ethically take in the field – that is the draw weight table below, not the price tag.

Legal: You do not need a license, permit, or any paperwork to buy, own, or practice with a compound bow in the US – walk into a shop and walk out with one the same day. That changes the moment you want to hunt with it: almost every state requires a valid hunting license plus a bowhunting-specific endorsement or stamp, and many also require a hunter education certificate before you can buy a tag. Requirements vary by state, so check your state wildlife agency before you plan a hunt, not before you buy the bow.

Draw weight is the first question most new bowhunters ask. The honest answer is about ethical penetration, not maximum poundage – here is a realistic guide:

Draw weight	Ethical for	Notes
30-39 lb	Small game, target practice	Not recommended for deer
40-49 lb	Whitetail deer (closer range)	Around the legal minimum for deer in many states
50-59 lb	Deer, antelope, black bear	The all-round sweet spot for most hunters
60-70 lb	Elk, moose, all big game	Where most fit adult hunters land

Is a 40-50 lb bow enough for a deer? Yes. 40 lbs is the widely accepted minimum for whitetail, and 50 lbs gives comfortable margin for a clean, ethical kill at bowhunting range. Shot placement and a sharp, well-tuned broadhead matter far more than a few extra pounds – see the broadheads and arrows guide for the weight and FOC thresholds that actually drive penetration, and always check your state’s legal minimum before you hunt. For the hunting-specific side of choosing a bow – noise, treestand manoeuvrability, camo and cold-weather draw – see best hunting compound bows.

Dig deeper into the topics that matter most for choosing and setting up a compound bow:

• Best compound bows – how to choose the right one without chasing spec-sheet speed.
• Best compound bows for beginners – forgiving, adjustable starter bows.
• Best hunting compound bows – what actually matters in the field.
• Compound bows for women – fit, draw length and weight considerations.
• Best youth & kids compound bows – sized and weighted for young archers.
• Left-handed compound bows – eye dominance and what your options are.
• Mini and compact compound bows – short ATA bows and who they suit.
• Buying a used compound bow – the checklist and red flags before you hand over cash.
• Compound bow brands compared – how the major manufacturers actually differ.
• How to shoot a compound bow – stance, anchor and release, step by step.
• Compound vs. recurve bow – which style is right for you.
• Compound vs. crossbow – draw cycle, cocking effort and regulations.
• Parts of a compound bow explained – every component and what it does.
• Compound bow risers – the backbone of the bow and how design affects feel.
• Best arrows for a compound bow – matching spine, weight and length to your setup.
• Bow sights – single-pin vs multi-pin, pin size and what to spend.
• Peep sights – sizing, rotation fixes and setting height.
• Arrow rests – drop-away, containment or blade, and how to time one.
• Release aids – wrist strap, thumb or hinge, and the trigger-punch problem.
• Stabilizers – length, end weight and setting up a back bar.
• Bowstrings – when to replace one and creep vs stretch.
• Bow press – what it does and whether you need to own one.
• Measuring a compound bow for a case – why axle-to-axle is not your bow’s real length.