STEAMBOW POWERUNIT Compressed air quick release system for Excalibur crossbows
High performance at the push of a button

The Steambow PowerUnit is a pneumatic quick-release system for the Excalibur Micro 355, Bulldog 400, and Bulldog 440. The same system is also used with the Steambow Onyx, which was specially developed for the PowerUnit.

The quick-release system is powered by compressed air stored in small and light pressure bottles like they have been used in paintball for decades.

The Steambow system is very robust and easy to use. A main valve regulates the cocking process, everything else, like a bow's manual safety or trigger, remains unchanged.

When the crossbow is cocked, the limbs are in exactly the same position as they would be without the PowerUnit. All performance data, such as arrow speed, precision, etc., therefore apply unchanged to a Steambow as well.

The PowerUnit also allows for even the most powerful recurve crossbow to be folded into a convenient format.

Bolt speed
0
fps
0
m/s
Draw weight
0
lbs
0
kg

Specifications for use with the Excalibur Bulldog 440

DELIVERY INCLUDES

Compressed air bottles and refilling equipment are not included. You can find them in the Steambow shop.

  • PowerUnit
  • Valve block
  • 2 limb attachments
  • 2 dampers
  • Assembly material

ACCESSORIES

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Ready for a crossbow that packs a punch? Expand your Excalibur crossbow with a Steambow PowerUnit today!

How a Steambow works

Effortless cocking, near tool-less maintenance, substantially increased safety, collapsible limbs for easy transport: the Steambow PowerUnit pneumatic cocking system has it all.

Transport configuration
The limbs are folded to the mainframe. The Steambow fits snugly in a bag, can be stowed away to save space, or carried easily with a shoulder strap.

Steambow uncocked
Since the string isn't taut, it can easily be fitted in the lock. In this position, the Steambow is absolutely safe, since at this point there is no tension in the limbs and string.

Ready to shoot
At the push of a button, the Steambow is silently tensioned and is now ready to fire.

Why a Steambow?

COLLAPSIBLE FOR EASIER TRANSPORT

You can use the quick-release pins to fold the limbs alongside the mainframe in seconds. This makes the crossbow narrow enough to fit easily in a normal bag.

SILENT COCKING

You can cock the limbs almost silently within one second. When you relax the limbs after firing, a quiet hissing can be heard as the air escapes.

HIGH RATE OF FIRE

The string is hooked into the latch with the limbs relaxed, the next bolt is loaded, and the Steambow is ready to be cocked and fired.

ENHANCED SAFETY

You decide when to cock the limbs, ideally just before firing. This precludes many dangerous situations.

SAFE LOADED STORAGE

A Steambow can be stored and transported with a loaded bolt at zero risk of discharge. The optional disposable CO2 cartridges also allow a Steambow to be made ready in seconds after being stored for years.

VERSATILITY

The automatic cocking function allows you to cock the Steambow without effort in any orientation and position, including in tight tree stands.

TOOL-FREE STRING REPLACEMENT

The limbs of a conventional crossbow are under great tension even when the bow is not cocked. The string cannot be removed from the limbs without special tools or jigs. With a Steambow, you need no tools whatsoever to replace the string.

LONGER LIFE

The limbs of a conventional crossbow are always under tension and can lose their strength over time, especially when exposed to high temperatures. As the limbs of a Steambow are under no tension until pressure is applied, this risk is eliminated.

PRECISION MANUFACTURING

Made of high-quality aluminum alloys on state-of-the-art CNC machines. All surfaces are hard anodized with a matte finish. This ensures high performance and a long life.

ALWAYS READY TO GO

Even if your air tank is empty, you have no compressor or backup tank, and you have used your last CO2 cartridge – you can also cock your Steambow manually with the right accessories.

TECHNICAL DATA

Weight
3,85 kg
Length
91 cm
Powerstroke
37,1 cm
Effective range
120 m
Draw weight
300 lbs / 136 kg
Bolt speed
440 fps / 134 m/s

Specifications for use with the Excalibur Bulldog 440

Support

Legal note

Steambow is an Austrian company operating under Austrian law. It is the buyer’s responsibility to make sure the products they order from Steambow are legal in their country and can be shipped there without any issues arising from customs and other restrictions. Steambow GmbH assumes no liability for difficulties arising from the legal situation in the buyer’s country.