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Beaufort Naval Armorers Breeches & Trunions

B.N.A. Cannon Breech Loader Mechanisms – Basics

Through the years Beaufort Naval Armorers has refined their breech mechanisms by experimenting with various historical designs. All breech loader designs work sufficiently but several are more desirable than the others for their simplicity and agreement with modern ordnance design parameters.

Therefore, the two most common B.N.A. breech closures are:

  1. The ‘Simple Screw Breech’
    The breech block is fastened to the cannon with a lanyard to prevent loss. Multiple entrance threads accommodate faster speed of opening and closing operation.
    • The ‘simple screw breech’ can be machined to be interrupted thread for a still faster operation. The interrupted thread breech mechanism can be hinged to swing open in any direction. (The machining process for this breech mechanism is time consuming, but it is available as an option.)
  2. The Typical U.S. Artillery Style ‘Sliding Block Breech’
    The B.N.A. sliding breech block opens and closes easily. It is a U.S. breech loader design which offers mechanism simplicity and is also sophisticated and safe. The breech block slides to the side to open (but it could be manufactured to slide in another direction). Both the “open/loading position” and the “closed/firing position” of the breech block are held snugly in place by cam pin pressure. A spring loaded cam pin prevents unrestrained sliding motion of the breech block. The sliding breech block stays attached to the cannon.

sliding breech mechanism

Beaufort Naval Armorers’ most popular cannon barrel style is the traditional English pattern. B.N.A. makes every effort to maintain their traditional appearance when breeches are upgraded from muzzle loaders to breech loaders. The breech loader mechanisms are barely noticeable and Simple Screw Breeches are often undetectable.

B.N.A. Cannon Trunions

The manufacturing technique for Beaufort Naval Armorers’ cannon trunions is a trade secret. The trunions cannot be removed. The trunions’ design varies between the styles of cannons, but all function according to mature modern ordnance design. All B.N.A. trunions have passed ‘extreme’ high pressure testing 100% of the time.

All parts of a B.N.A. cannon are machined* from solid high strength bar stock/ rolled shafting material . There are no castings of any B.N.A. cannon parts including the trunions. B.N.A. uses ordnance grade or marine grade bronze or brass and ordnance grade or marine grade stainless steel for all cannon parts. Beaufort Naval Armorers uses modern ordnance engineering techniques. Quality, safety, and beauty are the three primary manufacturing goals.

*There is one exception to our rule that all B.N.A. cannons and cannon parts are machined from solid shaft and bar stock…

B.N.A. offers a custom made high strength cast manganese bronze Eprouvette Mortar design. “The B.N.A. Golf Ball Mortar.”