Choosing the Right Slingshot Ammo Size
The right ammo size doesn't just change your accuracy — it changes how your whole setup feels to shoot. Whether you're punching paper, plinking cans or running simulated hunting courses, the ammo you choose affects flight, wind resistance and how well your bands perform. At Natty Catty Bands, we tune every band set to give you the flattest, most efficient flight possible for your chosen ammo — without wasting energy or making your setup unpleasant to shoot.
Understanding Trajectory
Every projectile follows an arc. High-powered rifles still account for rise and fall over distance, and slingshots are no different. The goal isn't to eliminate arc — physics won't allow it. The goal is to create the flattest, most useful trajectory possible while keeping your setup smooth, efficient and accurate.
That's why modern band tuning focuses on efficiency and matched ammo sizes rather than simply using the thickest latex available. If brute force worked, we'd all still be shooting oversized multi-band catapults like “the good old days of Theraband Gold.” The sport has moved toward lighter, more refined setups because they simply perform better in the real world.
7mm Steel — Speed and Precision
7mm steel is one of the flattest-shooting ammo sizes in common use. It's fast, efficient and excellent for target shooting and precision work.
Strengths: Very flat trajectory, fast flight speed, lightweight and efficient — ideal for paper targets and accuracy-focused shooting.
Considerations: More susceptible to wind drift and light foliage deflections. In strong wind, when your bands are buzzing the best move is simply to relax your draw, wait for calmer air rather than forcing the shot risking fork hits and a big loss of power.
7mm pairs best with lighter, efficient band sets — 0.4 to 0.5mm latex depending on your draw and conditions.
8mm Steel — The Sweet Spot
For many shooters, 8mm is the sweet spot. It offers the flat flight and speed of smaller ammo while retaining more transfer of energy and handling wind more confidently than 7mm. It performs well on targets, holds up in varied conditions and feels smooth to shoot — a genuinely versatile all-rounder that suits a wide range of styles and setups.
8mm works well with 0.5 to 0.6mm latex depending on the season and your draw length.
9.5mm Steel — Power and Momentum
9.5mm has loyal fans for good reason. It's heavy, stable and largely unfazed by wind. Where it trades off speed and a flatter arc, it delivers strong momentum retention and a smooth, satisfying shooting feel that many experienced shooters prefer. It does require a heavier band setup to perform well, but in the right configuration it's a formidable choice.
For shooters who prefer larger ammo, steel up to 12mm is perfectly usable year-round with 0.7mm latex on a 25/20 taper — though it's worth noting that World Slingshot Association competition rules restrict ammo to between 6.35mm and 9.5mm, so anything outside that range is for recreational shooting only.
Matching Your Latex to the Season
One thing many beginners don't realise is that latex performs differently depending on temperature. Cold air stiffens latex, which reduces efficiency and changes how your setup feels — so what works perfectly in July can feel completely off by November.
Here's how we set up across the seasons:
Ammo Summer Latex Summer Taper Winter Latex Winter Taper
7mm steel 0.45mm 18/120. 5mm 20/12 8mm steel 0.5mm 20/12 0.6mm 18/12 9.5mm steel 0.7mm 20/15 0.7mm 25/20 10–12mm steel 0.7mm 25/20 0.7mm 25/20
For 9.5mm+, the band is thick enough that it doesn't lose much efficiency in the cold — but a taper adjustment brings it back to summer feel. The wider 25/20 winter taper generates more kinetic energy, helping the band retain heat longer and restoring the performance the cold would otherwise take away. Run a 25/20 in summer and it becomes too much band — you'll feel it immediately in your shot.
These aren't rigid rules, but they're a solid starting point. Your draw length and personal feel will always have the final say.
A Word for Beginners
If you're new to slingshots, the most important thing before anything else is accuracy. Before you even think about pest control or asking a landowner for permission, you should be hitting a 40mm spinner consistently. That's the benchmark that tells you your setup is dialled in and your shot placement is reliable.
It's also worth understanding the legal landscape clearly. In the UK, catapults are neither listed as a banned method of despatch nor as an approved one — they sit in a grey area that puts the full responsibility on the shooter. That means accuracy, ethics and proper permission aren't just good practice, they're everything. Nothing deserves to suffer, and responsible shooters take that seriously.
That said, pest control is only one small part of what this sport is about. The fastest growing side of slingshot shooting right now is competitive target shooting — with events and competitions running up and down the country throughout the summer months. It's a genuinely skilled discipline, a welcoming community, and a great place to develop your shooting with plenty of camaraderie along the way.
A Note on Responsible Shooting
If you are using a slingshot for pest control in the UK, the rules are clear. You must have the landowner's written permission, operate within UK law and use proper backstops at all times. Slingshots must never be used on public land, in parks, National parks or protected areas — the legal consequences are serious and wildlife laws are there for good reason.
Ethical shooting matters too. Accuracy isn't just about hitting a target — it's about clean, humane shots when it counts. That means practising your placement, knowing your limits and never taking a shot you're not confident in.
Quick Reference — Finding Your Setup
7mm for speed, flat flight and precision
8mm for all-round versatility and reliable performance
9.5mm for stability, momentum and a smooth, powerful feel
10–12mm for recreational shooting with maximum impact
The best setup is the one that matches your draw length, your shooting style and what you're shooting at. Modern slingshot tuning is about efficiency, not force — a well-matched setup will outperform an overpowered one every time.
If you're not sure where to start, we're happy to help you find the right combination. That's what Natty Catty Bands is here for.
Frequently Asked Questions
What ammo size is best for beginners? 8mm is the most forgiving starting point. It's fast enough to shoot flat, heavy enough to handle a bit of wind and pairs well with mid-weight band sets. Once you're consistently accurate with 8mm, branching out to 7mm or 9.5mm becomes a natural next step.
Does latex thickness really make a difference? Yes — significantly. The wrong latex for your ammo size either wastes energy or creates too much resistance, both of which hurt accuracy and comfort. Matching your latex to your ammo and draw length is one of the most important tuning decisions you can make.
Why does my setup feel different in winter? Cold air stiffens latex, which reduces snap and efficiency. Stepping up your latex thickness or widening your taper in winter compensates for this and brings your setup back to its summer feel.
What are the WSA competition ammo rules? World Slingshot Association rules require ammo to be between 6.35mm and 9.5mm for competitive shoots. However ,here in the UK we don’t use anything smaller than 7mm due to our events being outdoors. Anything smaller or larger is fine for recreational use but cannot be used in sanctioned competitions.
Is slingshot pest control legal in the UK? Catapults are neither listed as a banned nor an approved method of despatch in the UK — they occupy a legal grey area. Any pest control use requires the landowner's written permission and must be carried out humanely and within the law. Accuracy is essential. If you're not consistently hitting a 40mm spinner, you're not ready for pest control.
Are there slingshot competitions I can enter? Absolutely — and this is the fastest growing side of the sport. Competitions run throughout the summer across the UK, catering to all skill levels. It's a great way to improve your shooting, meet the community and test your setup in a supported environment. I will post up coming competitions on the website and you will find them here on Facebook
What's the difference between a taper and a straight band? A tapered band is wider at the fork end and narrower at the pouch — this shape accelerates the ammo more efficiently than a straight band and gives a smoother, more controlled release. The taper dimensions (e.g. 20/12) refer to the width in millimetres at the fork end and pouch end respectively. There is a safety aspect to the taper design as well bands are designed to break at the pouch and if you have cared for your bands this is where they will break resulting in the Latex hitting your hand if you havn’t seen the early signs rather than the bands coming towards your face and eyes
Any other questions feel free to drop me an email here.
