Thursday, July 19, 2012

Casull 290

The Casull 290 was a semi-auto .22 long rifle caliber gun invented by Dick Casull in the 1960's.  Only a very few were made.  They were an open bolt semi-auto.  The design was the basis for the American 180 machine gun, first manufactured by Voere in Austria, then by American Arms in Utah, and ILARCO and Feather Enterprises.  Semi-auto American 180 rifles were made by Voere, and imported by Christopher Associates in California, as well as made in the USA by American Arms and by ILARCO, but they all fired from a closed bolt.

Patent 3319523 covers the drum and patent 3366010 covers the feed.

Monday, November 14, 2011


RPB Industries Inc. made semi-auto open bolt versions of the MAC style machine guns from 1979 until 1982. In 1981 and 1982 ATF issued formal rulings that several open bolt semi-auto guns were in fact machine guns, even though they only fired one shot per trigger pull. ATF decided the guns were too easy to make into machine guns. Covered by ATF Ruling 82-8 were the RPB rifles and pistols based on the M10 machine guns made first by Military Armament Corp. RPB made these guns in .380 ACP caliber, 9mm and in .45 ACP. Most of them were pistols, but some rifles were also made. Pictured here is a pistol version of the M11-A1, which they called the SM11-A1, the smaller .380 caliber gun. The 9mm and .45 guns were made on a larger frame size.

Here is the right side of the gun. RPB used the same basic frame as the machine gun, including the markings. They hand stamped the letter "S" in front of the M11-A1 model marking, denoting this one was a semi auto, not the machine gun. The serial number also starts with "SAP" for semi-auto pistol. All of the .380 guns I have seen, either machine guns or semi-autos have a serial number that starts with "380," followed by 4 digits. Aside from not having notches cut for the shoulder stock in the rear plate, and not having the axis pin for the selector drilled through the frame, the frame of the semi-auto and full auto guns is the same. Note that on this one, the screw holding the takedown pin in place is a replacement, originally it should be a flat head screw, so it would look the same from either side.

Here is the left side of the pistol.

Here is a closeup of the markings.

Here is the gun field stripped. The upper receiver and bolt assembly are the same between the semi-auto and full auto guns.

Here is a view of the bolt, showing the firing pin is a fixed metal bump on the chamber face of the bolt, typical of most open bolt firing firearms, whether semi-auto or full auto.

Here is a vire into the frame of the pistol. Note at the rear the holes for the latching assembly for a shoulder stock are in place, although the latch assembly is omitted. The big difference however is in the pin that holds the disconnector and sear. Rather than being on a pin that is drilled through the frame (and which also functions as the selector on the machine guns) they are instead on a "U" shaped metal channel which is welded into the frame. This is meant to do two things, make it more difficult to remove the disconnector, and to differentiate the machine gun and the semi-auto frames, by the presence or absence of the hole through the frame.

Here is a closeup of the assembly. Removal or alteration of the disconnector will enable the gun to fire as a machine gun. It won't be select fire, but rather full auto only. Typically this was accomplished by either removing the tooth at the front part of the disconnector or by cutting the round protrusion on the side of the trigger that engages the disconnector. Either modification will result in making a machine gun, with all its attached legal consequences.

Here is a view of the rear of the gun. Although the frame has notches for a shoulder stock, the rear plate welded to the frame does not. The pistol can be modified to have a shoulder stock, to look more like the machine gun, but shoulder stocked pistols require registration in the USA, so know the law before you do it.

A view of the underside of the pistol, showing the cutouts for the shoulder stock latching assembly, and the notches in the frame, but not in the back plate.

The guns were originally available with two magazines, a short one and a long one. Both have the Cobray snake logo first used by Mitch WerBell's Military Armament Corp. RPB gained the use of the trademark when they obtained the assets of the original Military Armament Corp.

Monday, January 3, 2011

ATF documents on the Franchi 1962 carbine

Here is a set of letters and memos from ATF on the 1962 semiautomatic Franchi carbine, imported by Mars Equipment Corp. This is the first time I know of where ATF (in this case its predecessor agency, the Alcohol and Tobacco Tax division of IRS) decided a semi-automatic gun was a machine gun because it could be rigged to fire full auto. In this case they said that interfering with the sear with a piece of wire could get it to fire full auto. In addition they noted the open bolt design was characteristic of machine guns. Finally, although the ad was not part of the ATF materials, the importer apparently advertised it was a "legal" machine gun, or machine gun-like. These are the same or similar reasons ATF used in reclassifying the KG-9 pistol and the open bolt MAC style guns many years later. In between ATF allowed the sale of other open bolt semi-auto guns, and used different reasons to classify the Spitfire as a machine gun; that it could be fired full automatic without altering the gun. According to the memos a total of 52 guns were imported, ATF required they all be registered as machine guns by Mars, which was an SOT at the time.

At the same time as Mars was looking to bring in a semi-automatic version of the LF57 machine gun, they also wanted to import a semi-automatic version of the CETME rifle, and these memos also address that gun, and ATF considering some early versions of the semi-auto version to be a machine gun.