Posts Tagged ‘designer’

Charles St. George and the Bushmaster M17-S Bullpup

M17-S bullpup with a reflex sight.

M17-S bullpup with a reflex sight.

In Bushmaster’s product line-up, the M17-S bullpup was always the odd one. It shared a few components with the AR-15 rifle, but remained more of a low-volume curiosity for its entire 13-year product run. This rifle has its origins in the Leader T2 rifle mentioned last week. In 1986 the Australian Army invited bids to replace the L1A1 rifle. Charles St.George submitted an improved select-fire version of the Leader T2 designated the M18. The M18 used a short stroke piston and a gas regulator, with the non-reciprocating charging handle, bolt carrier and two action rods of the T2. The plunger ejector was changed to a fixed ejector like the Stoner 63. A folding stock was added. Beta light sighting system was to be standard. The Australian army eventually adopted the Steyr AUG instead and produced it under a license as F88.

The designer with his rifle.

The designer with his rifle.

Charles re-designed the trigger mechanism and converted the M18 into a bullpup rifle named the ART30. Once fully developed it was licensed to Bushmaster as M17-S. Probably to make use of more common parts, the U.S. version used AR-15 type plunger and a further altered trigger mechanism. A heavier extruded receiver added noticeable extra weight. The lower receiver was also altered  in a way which made stripping and removal of the bolt carrier assembly more difficult. Rudimentary emergency open sights were built into the “carry handle”, but it was expected that an optical sight would be used. At the time, the reliance on optics for a defensive rifle was considered a flaw by most.

Partly as the result of those changes, the rifle came out somewhat heavy, with a spongy trigger and tended to retain heat. The heavy weight was mitigated by the excellent balance and very low felt recoil. With right-hand only ejection, it was also an awkward fit for left-handed users. Since bullpups were new, few training materials existed and most shooters viewed the manual of arms as awkward. One major plus of the M17-S was its use of the standard STANAG magazine. During the ban years (1994-2004), AUG magazines were extremely expensive, while AR-15 magazines remained at least somewhat affordable. The rifle itself cost about two-thirds of an AR-15 because the design allowed cost-effective manufacturing.

K&M modified M17S with 1-4x GRSC scope

K&M modified M17S with 1-4x GRSC scope

Recently, I test-fired an M17-S modified by K&M Aerospace. The modification started with ventilating the receiver to reduce weight by half a pound and to improve air flow. Combined with the already thick barrel, the ventilation greatly improved the sustained fire capability. Use of a vertical foregrip further insulated the support hand from the barrel heat. The “carry handle” was removed and replaced with two rails, permitting the use of standard AR-15 optics and other accessories. The longer rail also provided useful separation between the front and rear backup sights. Because of the central balance of the original rifle, addition of accessories didn’t make the gun too front heavy. Fired with GRSC 1-4x scope set to 4x, this modified rifle shot at 2MOA from prone with plain American Eagle 55gr ball. Surprisingly, the mechanical noise of the operating parts was not noticeable at all.

The major issues with the M17-S —weight, trigger quality and awkward take-down—have been addressed in the next rifle designed by St.George. I will cover it in the next chapter of this tale.

The Making of a Gun Designer: Charles St.George

Charles St. George at the range

Charles St. George at the range.

Bushmaster M17 bullpup

Bushmaster M17 bullpup

On the way to SHOT Show last year, I met Charles St.George. I didn’t know who he was, but somehow the Bushmaster M17 came up in conversation and turned out that he was the original designer. It was therefore no surprise that the rifle he displayed at the 2011 show looked like a very brawny M17. The Leader 50, while internally quite different from the M17 used the same basic extruded receiver design as the .223 bullpup. But the internals of the upcoming 50BMG rifle were based on a design of which I had not heard before, the Leader T2.

Charles St.George was born on Malta but moved to England with his parents at a young age. As a child, he had a Colt Peacemaker replica which even came with full-size dummy cases loaded with caps. The gun itself was precision die cast from zinc and Charles played with it until the toy literally fell apart. When his father’s regiment, the First Cheshire, got posted to Libya, Charles tried to replicate the zinc toy in steel. After a month of work with a hacksaw and a file, he had something only slightly resembling the intended form. “The experiment helped build arm muscles, at least!” he joked.

Upon returning to England, he decided to build a .303 semi auto rifle. Scotland Yard sent an Inspector from the Hampshire Constabulary to interview me at home before granting permission. Perhaps having a military father helped. The ammunition had to be kept at the Bisley Rifle Range and used cartridges logged in a register. The rifle he built used a simple tilting lock that locked the breech bolt into the receiver tube. A friend helped machine some of the parts, the rest were fashioned by hand. At the range it would not fire. In retrospect, Charles says that was lucky, for the rifle would have blown up. He knew nothing about metals, heat treatment or the designing of real guns.

As an adult, Charles immigrated to Australia started to tinker again. He built .223 semi auto rifle prototypes until he had a beautiful select-fire weapon with an aluminum receiver somewhat like the AR15 and a non reciprocating charging handle like the L1A1. Long stroke gas system used a piston pinned to a tube which housed the return spring and held to the bolt carrier by a wedge held in place by the cam track in the receiver, a triangular breech bolt and wooden handguards. The design eventually entered production around 1978 as the Leader T2. In use, this gun has particularly mild recoil, especially when compared to an AR15. Forgotten Weapons shows the T2 disassembly process on video.  They also feature photos of a pre-production sample with a wood stock made before the Zytel furniture was ready.

T2 has very mild recoil

T2 has very mild recoil.

Left-hand charging handle does not reciprocate on firing.

Left-hand charging handle does not reciprocate on firing

The Leader T2 production went smoothly because the gun was designed from the start to be extremely efficient. The receiver was based on a 16 gauge steel square tube. Dupont provided the expertise for the Zytel parts, which had not previously been used on an assault rifle. The triangular bolt design (subsequently used on the Serbu rifle, the R4 and Barrett 82A1/M107) simplified the barrel extension and the bolt broaching process. The barrel blanks from Parker Hale were rifled with a simple button rifling machine also designed by Charles. It rifled a barrel blank in about 20 seconds. While T2 resembles an AR180 superficially, it is even simpler inside. All major parts can be removed for cleaning in seconds and stay captive to simplify the take-down. It used common STANAG (M16) magazines.

T2 was shown to represenatives of Italy, Portugal and Oman. About 2000 were eventually exported to the US and a few to Africa. By the time the 1989 and 1994 bans in the US caused the cessation of the production of the T2, Charles St.George had already moved on. His next rifle is familiar to Americans as the Bushmaster M17. We will talk about that design next week.