A Crossbow with Balls ;)
For several years now, my core topic on YouTube has been a very specific niche: tactical magazine-fed crossbows capable of rapid repeat fire. These compact systems — roughly comparable in size to an MP5, PDW platform, or a compact AR-15 without a barrel — combine portability, modularity, and surprising effectiveness.
Early designs typically used detachable magazines holding five or six bolts. The introduction of the Steambow M10 pushed the concept further with ten-shot bolt magazines. But with the new B08 system, Steambow takes a radically different approach — abandoning bolts entirely in favor of spherical projectiles.
Transparency & Affiliate Disclosure
I have been collaborating with Steambow for roughly two years. This partnership grew out of genuine enthusiasm — long before any cooperation, I had already invested several thousand euros in their products.
This collaboration is purely affiliate-based:
- I do not receive any flat fees or sponsorship payments
- I only earn a commission if someone purchases through my link:
- Buyers receive 10% off their entire order at steambow.at when using that link
- Use my Link: https://bit.ly/B08Set
An additional partnership with Steambow USA is planned, which will extend this discount to North America and other regions. For now, international customers can already order through the Austrian store (steambow.at).
My opinions remain independent, and I openly discuss both strengths and weaknesses.
What Makes the B08 Unique
The B08 is a standalone system currently sold only as a complete package. While it is technically based on Steambow’s modular ecosystem, it is not a simple plug-and-play upper for existing platforms.
The reason is straightforward:
👉 The lower receiver must be modified for compatibility.
At present, this modification is performed exclusively by Steambow. As a result, the B08 cannot yet be purchased as a standalone upper.
In the future, the company plans to offer the upper separately together with a retrofit kit that will allow users to modify their own lower receivers. For now, however, that remains a future development.
From Bolts to .68 Caliber Projectiles
Instead of bolts, the B08 fires .68 caliber spherical projectiles — the same diameter used in paintball.
The detachable magazines are roughly comparable in size to extended 9 mm stick magazines (such as those used in AR-pattern PCC platforms) and hold eight rounds.
Unlike many earlier ball-shooting crossbows, the B08 uses a very different launch principle:
- The projectile does not roll down a barrel
- It receives no spin stabilization
- There is no Magnus effect
Instead, a shuttle accelerates the ball forward and releases it without rotation. This produces a surprisingly stable flight path despite the smooth spherical shape.
Effective engagement distance is approximately 20 to 30 meters (65–100 ft). Beyond that range, the system is not intended to perform. Precision is slightly lower than that of a bolt-firing AR-6, which is expected given the physics of spherical projectiles.
Reliability Compared to Earlier Ball Systems
Ball-firing crossbows are not new. However, many earlier designs suffered from reliability issues or even safety concerns.
The B08 inherits the mechanical robustness of the AR-6 platform, widely regarded as one of the most durable magazine crossbow systems available. In practice, it feeds reliably with a surprisingly wide range of projectile types — including very inexpensive options.
Projectile Types — Extreme Versatility
One of the B08’s most compelling features is the sheer variety of compatible ammunition. Few launch platforms offer this level of flexibility.
Lightweight Nylon Balls (Standard)
These are supplied with the system and are extremely light.
Ideal for:
- Indoor practice (e.g., basement training)
- Short-range shooting
- Paper targets
- Low-risk recreational use
They allow training on targets that would be unsuitable for bolts.
Rubber and Polymer Balls
A wide range of options exists:
- Budget rubber balls
- Premium rubber projectiles
- Polymer balls (often called polyballs)
Polymer projectiles are particularly interesting: smooth, reliable, and slightly heavier than nylon, offering improved consistency and energy transfer.
Lower-cost rubber balls may produce higher friction and can occasionally bind in magazines. A small amount of silicone oil typically resolves this completely.
Reballs and Paintballs
Reusable soft balls are extremely light and ideal for low-impact training scenarios.
Characteristics:
- Minimal injury risk
- Suitable for force-on-force practice
- Very low energy output
Standard paintballs also function normally, enabling marking or training applications.
Steel and Hybrid Projectiles
Solid steel balls (around 10 g) deliver significant momentum. However, they can rebound dangerously from hard surfaces and must be used with extreme caution.
Hybrid projectiles with steel cores and rubber or polymer coatings provide a balanced alternative — heavier than pure rubber but less hazardous than bare steel.
Lead Round Balls (Muzzleloader Type)
Heavy lead balls originally intended for black-powder firearms also work exceptionally well.
Typical characteristics:
- Very high momentum transfer
- Surprisingly acceptable accuracy
- Slow but powerful trajectory
Depending on the limb used, these projectiles can produce energy levels that should not be underestimated.
Specialty Projectiles
Additional compatible options include:
- Pepper balls (chemical irritant payloads)
- Marking or dust-effect balls
- Other experimental spherical projectiles of matching diameter
This versatility allows the platform to be configured for a wide range of purposes, from recreational shooting to specialized applications.
Power Through Interchangeable Limbs
Like other Steambow systems, the B08 supports multiple draw weights:
- 35 lbs (standard)
- 55 lbs
- 75 lbs — excellent balance of speed and system stress
- 90 lbs
- 120 lbs — maximum officially supported configuration
With lightweight projectiles and the weakest limb, energy output can be around 2–3 joules.
Using the 120-lb limb with heavy lead balls can raise this to roughly 20 joules.
Stronger limbs may physically fit but are not officially approved for sustained use.
Use Cases — From Recreational Shooting to Specialized Roles
The B08’s flexibility allows it to fill multiple roles depending on configuration:
✔ Recreational plinking at short range
✔ Indoor or backyard training
✔ Target shooting with reactive objects
✔ Simulation or training scenarios
✔ Less-lethal defensive concepts (where legally permitted)
Being able to shoot objects such as cans or steel targets — normally unsuitable for bolt-firing crossbows — dramatically increases the fun factor.
The Controversial High-Visibility Color
One feature that initially divides opinion is the bright yellow finish.
This is intentional. In high-stress situations, the color provides immediate visual distinction from lethal platforms, signaling a less-lethal system.
While more traditional finishes such as black or tan would appeal to many users, the distinctive color gives the platform a unique identity — and quickly becomes familiar over time.
Final Thoughts
The Steambow B08 is not a replacement for traditional bolt-firing crossbows. Instead, it represents an entirely new category.
It combines:
- High modularity
- Exceptional ammunition versatility
- Proven mechanical reliability
- Broad application potential
- Outstanding recreational value
Whether used as a training tool, a recreational launcher, or for specialized purposes, few systems currently offer this level of flexibility in such a compact format.
