Large Diameter Arrows for Indoor Target: Cut Lines, Score More

Shooting indoor target and wondering why the top archers use those chunky, oversized arrows? Those are large diameter arrows — “fat shafts” — and they exist for one clever reason: to catch more scoring lines. In indoor target archery, an arrow that merely touches a higher scoring ring counts for the higher value. A wider arrow touches more lines, so it scores more points on borderline shots. Over a full round, that can be the difference between winning and second place.

Here is the simple logic: indoor distances are short (commonly 18 meters / 20 yards), so you do not need a fast, skinny arrow that fights the wind. You want the fattest legal arrow that flies well, because every extra millimeter of diameter helps you cut lines. It is a strategy unique to indoor target — and it genuinely works.

In this guide, you will learn what large diameter arrows are, why they boost indoor scores, the rules and trade-offs, and how to choose the right ones. We will compare them to skinny arrows in clear tables and share pro tips and mistakes. By the end, you will know if fat shafts belong in your quiver. Let us cut some lines.

What Are Large Diameter Arrows?

Large diameter arrows — nicknamed “fat shafts” — are thick-bodied arrows made specifically for indoor target shooting. Common examples are “23-series” shafts (about 23/64 inch in diameter) and other oversized aluminum or aluminum-carbon arrows. They are much wider than the skinny arrows used outdoors, where small diameter helps cut the wind.

They matter because indoor target scoring rewards arrows that touch scoring lines. A fatter arrow physically covers more area, so it is more likely to touch (and thus score) the next-higher ring on a close shot. That single design feature — width — is the whole point of a fat shaft.

These arrows are slow and heavy by design, which is fine because indoor distances are short. To browse options, you can see indoor target arrows options on Amazon. Want the basics of arrow sizing first? See our arrow spine vs weight guide.

“Fat shafts have one job: cut lines. At indoor distances, the widest legal arrow that flies well turns near-misses into higher scores — and over a full round, those points add up fast.”

Why They Boost Indoor Scores

Indoor target archery is a game of inches — or really, millimeters. Scores are tight, and rounds often come down to a single point. Large diameter arrows give you a real, repeatable scoring edge. Here is why they matter:

• Line-cutting math. If your arrow touches the line of a higher ring, you get the higher score — and a wider arrow touches more lines.
• Short distance, no wind penalty. Indoors there is no wind, so the fat shaft’s main downside (drag) does not hurt you.
• Tight competition. Indoor scores are so close that a few extra line-cuts per round can change your placing.
• Consistency. Quality fat shafts are well-made and group reliably at short range.

The bottom line: at indoor distances, choosing the widest legal arrow that you can shoot accurately is simply smart scoring. It is why nearly every serious indoor target archer uses fat shafts.

How “Line Cutting” Works

In target scoring, an arrow is awarded the value of the highest scoring zone its shaft touches — even barely. So if your arrow lands just outside the 10-ring but its edge touches the 10-line, you score a 10. This is called “cutting the line.” A wider arrow has more edge to touch lines, so on a shot that lands right at a boundary, the fat shaft is more likely to catch the higher ring.

Consider two arrows hitting the exact same center point, one skinny and one fat. If that point is just inside the 9-ring near the 10-line, the skinny arrow might stay a 9, while the fatter arrow’s wider edge reaches over and touches the 10-line — scoring a 10. Same shot, one more point, purely from diameter.

Multiply that across dozens of arrows in a round, and a fat shaft can add several points. That is the entire competitive reason these arrows exist. For more on how scoring works, see our how Olympic archery works guide.

The Rules & Max Diameter

You cannot just use the biggest arrow imaginable — governing bodies set a maximum arrow diameter for target competition. The common limit for indoor target classes is around 9.3 mm (which is where the popular 23-series shafts land). Arrows must not exceed the legal diameter, and points/nocks have limits too.

Key rule points:

• Max diameter (~9.3 mm) for most indoor target classes — fat shafts are built right up to this limit.
• Check your organization’s rules (World Archery, USA Archery, NFAA, your league) as classes vary.
• Some classes/distances differ. Outdoor and certain divisions require skinnier arrows.

So fat shafts are designed to be the maximum legal width for indoor. Always confirm your specific league or competition’s rules before buying.

Trade-Offs of Fat Shafts

Large diameter arrows are a specialized tool, and they come with real downsides outside their niche:

• Slow and heavy. The wide body creates drag, so they fly slowly — fine indoors, bad at distance.
• Poor in wind. That same width catches wind, so they are useless for outdoor target or hunting.
• Short-range only. They drop quickly, so they are made for 18m/20yd indoor, not 50–70m.
• Cost and weight. Quality fat shafts can be pricey and require proper spine matching.

None of these matter indoors, which is exactly why fat shafts dominate there and disappear everywhere else. Choose them only for their purpose.

How to Choose Indoor Arrows

1. Confirm your class rules and the legal max diameter (often ~9.3 mm indoor).
2. Pick a fat shaft near the max legal width that you can shoot accurately.
3. Match the spine to your bow’s draw weight and arrow length (fat shafts still need correct spine).
4. Choose a weight that flies well at 18m and clears your bow safely.
5. Use large vanes for quick stabilization at short range.
6. Tune and test to confirm they group tightly indoors.

Need help with spine? See our arrow spine vs weight guide and our Arrow Spine Calculator.

Fat vs Skinny Arrows

Indoor vs Outdoor Arrows

Curious about the broader split? See our indoor vs outdoor archery guide.

Common Mistakes (and Fixes)

• Mistake: Using fat shafts outdoors. They drift and drop. Fix: Use skinny arrows outdoors.
• Mistake: Exceeding the legal diameter. Arrows ruled illegal. Fix: Stay within your class’s max (~9.3 mm indoor).
• Mistake: Ignoring spine. Fat shafts still need correct spine. Fix: Match spine to your setup.
• Mistake: Expecting them to fix aim. They only help close shots. Fix: Build good groups first.
• Mistake: Hunting with target fat shafts. Unsafe and ineffective. Fix: Use proper hunting arrows.

Pro Tips

• Buy the widest legal shaft you can shoot accurately for max line-cutting.
• Keep separate indoor and outdoor sets for the right tool each venue.
• Match spine and tune — fat shafts still need to fly clean.
• Use large vanes for fast stabilization at 18m.
• Confirm league rules before competition to stay legal.

“Fat shafts are not magic — they are math. Shoot a good group near the line and the extra width upgrades your borderline arrows. Use them indoors only, match the spine, and let the diameter do its quiet work.”

Real-Life Examples

The league shooter. Priya shot a tight indoor group with skinny arrows and kept landing 9s right at the 10-line. She switched to legal fat shafts and several of those same shots became 10s — her round score jumped without changing her form.

The two-set archer. Marcus keeps fat shafts for winter indoor leagues and skinny arrows for summer outdoor. Using the right arrow for each venue, he stays competitive year-round without compromise.

The beginner who learned the limit. Sam tried his indoor fat shafts at an outdoor 50m shoot and watched them drift and drop badly. It taught him exactly why fat shafts are an indoor-only tool.

Are They Worth It?

Large diameter arrows are worth it if you: compete or shoot leagues in indoor target archery and already group well — the line-cutting edge adds real points. They are not worth it if you: shoot mostly outdoors, hunt, or are a casual beginner who is not yet scoring near the lines.

Final recommendation: If indoor target scores matter to you, get a quality set of legal fat shafts, match the spine, and use large vanes. For everything else — outdoor distance and hunting — stick with skinny or hunting-specific arrows. The right arrow for the venue is the whole game.

Frequently Asked Questions

What are large diameter arrows used for?

Large diameter arrows (fat shafts) are used for indoor target archery. Their wide bodies are designed to “cut lines” — touch the next-higher scoring ring on close shots — which raises your score. They are slow and only suited to short indoor distances, not outdoor target or hunting.

Do fat shafts really improve indoor scores?

Yes, for archers who already group well. A wider arrow touches more scoring lines, so borderline shots are more likely to catch the higher ring. Over a full round, that can add several points — often enough to change your placing in tight indoor competition.

What is the maximum legal arrow diameter for indoor target?

Most indoor target classes cap arrow diameter at around 9.3 mm, which is where popular 23-series fat shafts land. Rules vary by organization (World Archery, USA Archery, NFAA, local leagues), so always confirm your specific class’s maximum before buying or competing.

Can I use large diameter arrows outdoors or for hunting?

No. Fat shafts are slow and catch the wind, so they drift and drop badly outdoors, and they lack the speed, spine, and penetration needed for hunting. Use skinny arrows for outdoor distance and proper hunting arrows for game. Fat shafts are strictly an indoor target tool.

Why are indoor target arrows so thick?

They are thick on purpose to maximize “line cutting.” Since indoor distances are short and there is no wind, the usual downside of a fat arrow (drag) does not matter — so archers use the widest legal shaft to touch more scoring lines and gain points on close shots.

Do large diameter arrows still need the right spine?

Yes. Fat shafts must still be spined correctly for your draw weight and arrow length to fly cleanly and group well. Diameter helps with scoring, but proper spine is what makes the arrow fly straight in the first place. Match the spine just like any other arrow.

Final Verdict + Checklist

Large diameter arrows are a specialized indoor target tool built to cut scoring lines and add points. At short indoor distances with no wind, the widest legal fat shaft you can shoot accurately is a smart scoring choice. But they are slow and wind-prone, so keep them indoors only — use skinny arrows outdoors and proper hunting arrows for game.

Your quick checklist:

• ✅ Fat shafts = indoor target line-cutting tool.
• ✅ Wider arrow = more scoring lines touched.
• ✅ Stay within the legal max diameter (~9.3 mm indoor).
• ✅ Match spine to your setup; use large vanes.
• ✅ Indoor only — never outdoors or hunting.
• ✅ Best for archers who already group well.
• ✅ Keep a separate skinny set for outdoor distance.

Want to optimize your whole arrow setup? Pair this with our arrow spine vs weight guide and indoor vs outdoor archery guide.