RAFFICA: February 2005
By Dan Shea

Far better it is to dare mighty things, to win glorious triumphs, even though checkered by failure, than to take rank with those poor spirits who neither enjoy much nor suffer much, because they live in the gray twilight that knows neither victory nor defeat. - Theodore Roosevelt

I have received a lot of calls from readers over the last few years to return “Raffica” to life. For those who don’t know it, Raffica is Italian for “burst fire” or “Full Auto”, and it is inscribed on the selector of my old Beretta Modello 12 submachine gun. That, together with an outstanding AWC Systems Technology MK9A suppressor, and a red dot sight, was just the baddest little SMG I ever owned. We went everywhere together - strolls in the woods of New England, competitions, bowling pin matches, etc. I really liked that SMG.

Anyway, Raffica is a special place, where I have tried to help members of the shooting community solve machine gun or other NFA problems. Unfortunately, due to some personality traits, it is not possible for me to do this like I was the Answer Grape, and I may digress off into some other bizarre subject while writing. This has been attributed to me wearing my headband too tightly back in the Sixties, which is of course a bald and unadulterated lie that had been told by my enemies, may their tortured souls rest in peace...

Raffica is back in this issue, and if I have the time to do more, Raffica will return to visit the gentle readers of this monthly magazine again and again. - Dan Shea

Q- I have heard about three shot burst mechanisms that “Repeat”, or “Have a memory”, and when I shoot my Ruger AC-556, sometimes I get 2 shots, or one shot, or even the three shots I am supposed to get. What am I doing wrong?

A- You aren’t doing anything wrong, that is how the system in an AC-556 works. This isn’t the first time this question has come up, it is really fairly common. Perhaps the best way to answer it will be with an example. Your Ruger AC-556 is a true selective fire rifle. There is a manual safety at the front of the trigger guard, and at the right rear of the receiver, to the rear of the sight, is a toggle selector. You depress the button, and can select any of three firing modes- Semiautomatic, Three Shot Burst, and Fully Automatic. The AC-556 (Automatic Carbine, Caliber 5.56) does not have a “memory.” What this means to a shooter, is that the burst mechanism will fire a sequence of three shots when it is in burst mode regardless of whether the operator keeps the trigger depressed for all three. This does NOT mean that you depress the trigger and get three rounds. It means that if you let up on the trigger before all three rounds in the burst have been fired, the mechanism will stay at the point you stopped, and take up the count where it left off on the next firing sequence. If you are in burst mode, and fire one round, your next full depression of the trigger will yield only two shots. If you let up on the trigger after two rounds, then your next pull on the trigger will yield only one round. Once the mechanism has counted out three rounds, it will then be ready for another cycle of three.

A burst mechanism with a “memory” will automatically return to starting the burst count on each depression of the trigger, regardless of whether or not the sequence was completed in the initial firing. This means in a three shot burst mechanism such as an HK burst style trigger group, if you let off of the trigger before the three rounds have been fired, the mechanism resets and your next pull on the trigger will yield a full three round burst, unless you run out of ammunition or let off of the trigger too soon. Many machine guns have burst mechanisms in them, and many claim to have been the “first” with a burst. The earliest mechanism I have studied was in a Costa Rican contract Breda PG rifle in 7x57mm from the late 1930s that had a four shot burst mechanism. The burst group in the Breda PG is complex and hard to get to, it is inside the trigger group area and is a circular device. The Breda PG rifles did not have a fully automatic feature, just the burst, and some did not have anything other than semiautomatic fire capability. The example I saw was in the late 1980s at Knob Creek, and was fully transferable. It makes occasional appearances at shows as it has traded owners several times.

Perhaps the best way to illustrate the operation of a resetting burst mechanism is with a linear geared system- the Beretta 93R machine pistol. Under the right grip, there is an excellent, visible example, and I have photographed the sequencing to show one method. Many burst mechanisms are circular, and not readily visible. If you can mentally transpose the linear path of the gear onto a circular gear, the memory and reset part of the system will be very clear to you.
  • Figure 1 shows the burst system of the Beretta 93R. At “E”, there is a cam that is depressed by a slot in the bottom of the slide as it cycles. This activates the pusher lever.
  • Figure 2: The selector lever on the other side of the receiver has been set to semiautomatic, and the lever in the burst mechanism “A”, disengages the burst counter.
  • Figure 3: The selector lever “A” has now been placed on 3 shot burst. The spring relaxes the pusher lever “B” into start position, and the catch “C” is also in position.
  • Figure 4: The trigger has been pulled. This pulls the gear bar “D” forward, allowing the pusher “B” to enter the first position, and catch “C” is at the bottom position.
  • Figure 5: As the first round is fired, the slide moves to the rear, depressing the cam that can be seen in figure 1 as “E”. This drives the pusher “B” moving the gear bar down to catch on the first notch at “C”. As long as the operator keeps the trigger depressed, the gear bar will stay forward, held by the catcher, and the pusher has moved up one notch for the next cycle.
  • Figure 6: A repeat of cycle in Figure 5 leaves the catch “C” in the second notch, and the pusher “B” in position for the last cycle.
  • Figure 7: A repeat of cycle in Figure 5, now the catch “C” is at the top notch, and the pusher “B” is no longer aligned with any part of the gear. The cycle has ended at three shots. In order to reset, the trigger must be released forward. This will allow the gear bar to return to the rear, the catch will release it, and all components will return to a state ready to start the cycle again on pulling the trigger.

A premature release of the trigger during burst fire may yield one or two shots. However, releasing the trigger to the forward position, returns the gear bar (“D” in figure 4) to the rear position, and the pusher “B” and catch “C” also return to rest. Thus, each depression of the trigger yields a fresh start on the sequence, giving three round burst capability. As a side note, the Beretta 93R has a twenty round magazine, and one in the chamber, giving the operator seven cycles of three round burst.

Q- I have just found a Japanese machine gun magazine at a gun show, and had several people tell me different things. Some of them said it was for the Jap 96, some said it was for the Jap 99, and one guy told me they are interchangeable.

A- The best thing I can do for you is to show you a comparative picture, and a place to measure the magazine if you don’t have both available for comparison. In the photo, the Japanese Type 99 machine gun magazine is to the left, the Japanese Type 96 machine gun magazine is to the right. Note that the Type 96 may have similar grooves in the metal, but it has a more radical curve than the Type 99. These magazines are of different calibers and they are NOT interchangeable. The Type 99 magazine is for caliber 7.7mm Arisaka, which is a rimless case made for the rifles and light machine guns, with some loadings usable in the Type 92 Medium Machine Gun, and is not to be confused with the 7.7mm Type 92 (semi) rimmed ammunition used only in the Japanese Type 92 machine gun. The Type 96 magazine is for 6.5mm Arisaka (Type 2 ammunition with a lighter charge- the Type 2 ammunition had two charge levels) which has a more tapered case than the 7.7, thus the more radical curve. As a quick check of which is which, take a tape measure and lay it across the heavier metal section by the feed lips, front to rear. The wider Type 99 magazine will read approximately 3 5/16 inches, while the narrower Type 96 magazine will measure approximately 3 1/8 inches across. Both magazines are relatively rare, as are the feed devices for the Japanese Type 11 hopper fed machine gun. It was the custom of the individuals in charge of overseeing trophies that were returning from the island fighting in the South Pacific, to simply toss the magazines overboard into the ocean. This was considered adequately demilled for trophy use. How could a soldier shoot it if he didn’t have a feed device or ammunition? Many trophies came home without a magazine at all, and some few made it because a “buddy” would pack the magazine out separate from the gun. Thus, the magazines command premium prices on the collector market today, sometimes topping $1000 in value depending on rarity and condition. Usual prices are in the $400 to $600 range, however.

Q- I was reviewing the 1918 BARs on the market, and I have never seen a transferable one made by IBM. Did any of the IBM guns make it into the civilian market?

A- I have had the same question for many years. I knew a couple of employees of IBM, who wanted to get an IBM made BAR for their collections, just because they worked there. Finally, we found one in the hands of a collector in Maine, serial number 532559. Here is a picture of the correct IBM markings on this fully transferable, pre-Amnesty registered gun. IBM only made 20,017 BARs, according to the records from Jim Ballou’s book “Rock in a Hard Place: the Browning Automatic Rifle.” You might also check with Bob Landies at Ohio Ordnance, or Kent Lomont on this, they both advertise in SAR, and both have handled a lot of BARs

If you want me to find an answer for you, drop a line with the question. For space reasons I will probably edit it down, and won’t include names unless you request it. Send questions to: sareview@aol.com and note that it is a Raffica question.

Or mail to:
Small Arms Review - Attn. Raffica
631 N. Stephanie St., #562
Henderson, NV 89014

This article first appeared in Small Arms Review V8N5 (February 2005)
and was posted online on June 14, 2013


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