Guilford engineering oddity


This is about Guilford Engineering Associates (GEA), they company which utilized the Abe Flateau design to make the steel AP “cyclone” bullets which were mostly experimental, but somewhat used by the ATF and possibly other U.S. government agencies in 9mm 9x19…

Here’s something I stumbled across on a random Google search… If you type the phrase “Guilford Engineering” in quotations in Google, then the first result it lists is from a watchdog website called If you click on the link it actually goes to a misdirected link for something else, and you can’t even find any “Guilford Engineering” results on this fedspending watchdog site if you type it into their own search engine. But if you click on the cache link back on the Google result it will take you to the old archived Guilford listing in which is not there anymore for some reason??? Anyway, the cached listing says that in year 2000, the U.S. dept of Justice N.I.J. (the body armor testing guys, among other things), gave a grant for $294,750.00 to these guys!!! And again in 2001 for $80,990.00. Wow, I wonder what they were doing? Still doing cyclone testing? I had assumed that anything and everything that they could’ve done was accomplished back in the early to mid nineties, or at least by the late ninties? I did find a log here from 1998 that talks about a grant to Guilford for the RAP device (non-lethal): (search for “guilford” in text) and another log online that mentions the actual ring-airfoil system in 1997 where they got $299,000 in grant form… wow… If only they’d known how popular the Taser would become. Anybody know what ever happened to the G.E.A. guy - David Findlay?


Interesting research. Flatau and the guys who worked with/for him at Edgewood Arsenal and Guilford are an interesting topic. Below are the quotes I found in your link. I have seen the Flatau airfoils in 45 ACP and in 40mm (grenades) and discussed both with the guys at Edgewood in the mid-1980s (hoping to find that they made airfoil loads in 9x19mm-answer was “no”) but had not heard of the RAP loads. If there were 500K made some should have shown up somewhere. Does anyone have a photo?

Thanks DK!

"TITLE: TechBeat Winter 1998
Series: NIJ
Subject: Technology, Law Enforcement, Police
Published: January 1998
31 pages
65,207 bytes
NIJ Takes the RAP

It was the late 1960s, the era of the Vietnam War,
and Abraham Flatau was an aeronautical engineer
working for the U.S. Army, a young man full of
energy, curiosity, and bright ideas. He knew the
soldiers in Vietnam were having problems with
their rifle-fired grenades. Their grenades
required a high trajectory, which made them
impossible to use in the thick canopy of the
jungle. The heavy foliage invariably caused them
to blow up short of their target.

Flatau knew the solution was a projectile with a
flat trajectory, something that would fly straight
and fast, without the typical ballistic arc. He
also knew there were only two methods to achieve
this flat trajectory: increase muzzle velocity or
find a way to create aerodynamic lift in the
projectile. His solution lay with the latter
method. The result was the ring airfoil grenade, a
small explosive metal ring that looked like a
donut and spun like a bullet. Because it generated
lift while it flew in a low-drag mode, it had a
near straight-line trajectory. Flatau’s theory was
sound enough that a prototype was developed.
However, the Army never pursued it.

It was not until the 1970s, following the
shootings at Kent State University, that the
subject of the ring airfoil grenade came up again.
Like many law enforcement and military officials,
Flatau saw a need for a nonlethal device that
would give military police and law enforcement and
corrections officers more control over crowds
without the possibility of killing anyone.

Many of the crowd control devices at that time–
rubber and wooden bullets, for the most part–had
serious problems. They had to be skip-fired
(ricocheted) so they would hit people in the legs,
not in the head. This meant that even the smallest
piece of gravel or rock could bounce the
projectile in the wrong direction. At long range,
these weapons were disturbingly inaccurate, and at
short range, they could be lethal.

Flatau had the solution. He turned his explosive
ring airfoil grenade into the nonlethal ring
airfoil projectile (RAP), a 2-inch-diameter rubber
ring weighing about 1 ounce and banded with a
special paper wrapping designed to hold the shape
until impact. It was fired by a launcher-adapter
that fit over the barrel of an M-16A1 rifle and
propelled by a 5.56mm low-grain blank cartridge.
The RAP flew at 200 feet per second, spun at 5,000
revolutions per minute, and delivered about 39
foot-pounds of energy. Flatau created two
versions: the sting RAP and the soft RAP.

The sting RAP was of particular interest to
military police, who requested that it be accurate
enough to hit a man-sized target from 40 to 50
meters, just outside of rock-throwing range, and a
group of three people from 60 meters. Because one
sting RAP could be used repeatedly, simply by
rebanding it, it looked like a financially
feasible tool, whether it was used for crowd
control, in hostage situations, or as a training
device. The sting RAP has the potential to stop a
person, cause him to drop a weapon, or deter him
temporarily to buy time for officers to respond to
the situation. Biophysics testing showed the RAP
could not break bones or injure internal organs,
no matter how it was fired. It could, however,
break double-pane glass, which was an advantage if
one had to hit a subject inside a building.

Ironically, although the sting RAP was approved
for military use, it was never used. The Army
produced 500,000, but then left them on the
shelves where they remained for more than 15
years. The second version, dubbed the soft RAP,
offered a little extra punch–it had 18 cavities
embedded with tear gas that was released on
impact, but it was never produced.

Enter Lt. Col. Matt Begert, who specializes in
finding new technologies for the U.S. Marine
Corps, including information on nonlethal weapons.
It was during his research that Begert learned
about Flatau’s invention. And while making a
presentation on promising new technologies to a
group of research and development personnel,
Begert mentioned the ring airfoil grenade and its
more modern incarnation, the RAP. To his surprise,
Flatau was in the audience. Begert and Flatau
later got together, took the device off the Army’s
shelf, and fired it. It worked perfectly.

“It is as less-lethal as you can get,” Begert
says. “You can fire it pointblank and it won’t be
lethal. It won’t knock you down, and it’s round
[donut shaped, larger than an eye socket], so it
can’t poke your eye out. What it will do is get
your attention, and on some people, it will leave
a bruise.”

In 1997, the RAP came to the attention of the
National Law Enforcement and Corrections
Technology Center (NLECTC)-West in El Segundo,
California, where Begert and Flatau demonstrated
it to law enforcement and corrections officers. It
made such an impression that the National
Institute of Justice (NIJ), as part of its
continuing search for viable nonlethal devices,
has funded research into updating and adapting the
RAP for use by corrections and police agencies. A
grant to Guilford Engineering, of Guilford,
Connecticut, is expected to produce several
things: designs for a handheld, stand-alone RAP
launcher that will not look like a deadly weapon;
the development of a soft RAP embedded with
oleoresin capsicum (OC) that will release a 3- to
4-foot cloud on impact; and a design for a
pistol-like configuration such as a flare

“This whole thing is going to be an engineering
feat. The device is elegantly simple, but these
new designs are going to be a lot of work,” Begert

In the interim, existing RAPs have been taken off
the shelf and are being tested by three agencies.
The Los Angeles County Sheriff’s Department plans
to demonstrate and possibly employ them
operationally. The Federal Bureau of Prisons has
obtained some for testing, as has the Royal
Canadian Mounted Police.

For more information about the ring airfoil
projectile, contact Sandy Newett at the National
Institute of Justice, 202-616-1471."


Can someone either post a picture of a .45 Flateau Airfoil cartridge, or at least describe the entire cartridge? I am not aware of ever hearing of it or seeing one.


Some idiot named John Moss asked someone to post a picture of a Guilford .45 Airfoil cartridge to this thread. Fortunately, Lew Curtis contacted this fool and reminded John that he had one in his own collection, and should make his own picture of it, instead of shoving it off onto someone else. Well, Lew is too much of a gentlemen to actually have put it quite that way. At any rate, here it is. sorry about the delay on this. I can’t remember what day it is anymore, much less what I have in my collection.

The case is a normal “W-W .45 Auto” headstamped, plain brass case. I think in the photo it looks like a nickeled case, but it is not. The primer has a flat, nickeled cup and there is no primer seal. The projectile(s) consists of a milky-white transparent plastic 3-section sabot. Looking down into the hollow cavity, one can see a brass ring then a slim line of the plastic sabot, and then another brass ring. The bottom ring seems to be sitting on a steel obturator. The material of the obturator was verified as being steel by applying a magnet to the side of the brass cartridge case at the assumed height of the obturator.

I have no idea whether these rounds are common or scarce. I have not seen any at shows, or probably would have purchased it, as I truly ompletely forgot that I had one in my collection until Lew kindly described what he remembered seeing at APG. As is usual for him, his memory in that regard was perfect, and enabled me to go right to it in the collection.

John Moss


The photo of the cartridge sort of looks like a non-lethal child-safe version of a .45 “Scimitar” from project SCMITR. :-)


Here’s a drawing of the cartridge and one of the 2 projectiles in cross-section…no I didn’t cut it. Total weight of the round is 11.8 g.


Here is the so-called .45 Scimitar round. It was loaded in a new primed
empty nickeled-brass case made by Winchester, with headstamp “W-W .45
AUTO” and has a domed nickeled-cup primer with red primer seal. Note
the heavy cannelure below the case mouth, there to retain the nylon
sabot. The sabot is two piece. The point sticking up above it is a
sharpened-steel blade inserted between the two halves of the sabot. It
can be pulled out fairly easily, although I don’t like to do it, since
it may result in it getting too loose.

DK - as can be seen, the Guilford wind foil cartridge could really not
be confused for this thing. The sabots are not only different n the
quantity of sections, but also dramatically so in shape. It also has
the cannelure not on the wind foil round, and a nickeled case as well.

These gimmick rounds live a short life, and in my opinion, do NO represent the “finest hour” of cartridge innovation, design or development. Unfortunately (for the collector only perhaps “fortunately”), they abound in ammunition design since about the 1960s. Few if any of them survive, since they are basically worthless.

Paul - thanks for the nice drawing on the guilford round. I had not seen it before, that I can recall. Again, in my opinion, it is no wonder that the Guilford round went no where.

John Moss


[quote]DK - as can be seen, the Guilford wind foil cartridge could really not
be confused for this thing. The sabots are not only different n the
quantity of sections, but also dramatically so in shape. It also has
the cannelure not on the wind foil round, and a nickeled case as well.[/quote]

Ya… I realize that. I was just making a joke, and how many plastic / nylon .45acp specialty projectiles are out there with a 2-part vertical sectioned make-up like this. They are just vaguely similar I know.


I spoke with a GEA engineer by the name of Findlay a few years ago. He provided with me a tech drawing of the GEA 38 and 357 tubular rounds. If I can dig them up and get permission, I’ll post a scan of them.

The single GEA 38 I have is one of the favorite items in my collection. In the closeup picture below, you can see the ‘serrated’ border between the actual foil/cutting surface and the copper designed to ride the rifling. This border (faint/obscured on some corroded or discolored samples) is a key distinguishing factor between the PMC 38J and other rounds using a visually similar bullet.

The case stamp is R-P 38 Special.



One of the things that this group was working one was a line of non-lethal anti-riot impact weapons, and this may be what was being discussed; IIRC, the whole assembly was called the “Stingray”, and it was intended to be mounted on the standard M16/M4 rifle. It had a cup-type holder at the muzzle for a rubber ring airfoil, and that grenade was launched and simultaneously spun when a blank cartridge was fired in the rifle. The launched grenade was a stiff rubber ring about 3 inches across, and it would have delivered a significant punch to anyone catching one of these in the chest (but conceivably fatal to anyone getting hit in the head). The really weird thing about the way these things flew is that they had a very flat trajectory, as the grenade provided its own lift while spinning (As a side-note, I remember seeing a plastic child’s toy a while ago that worked the exact same way; you threw it and spun it like a football at the same time, and it would give you an amazing distance with some very unexpected trajectories). Here’s a picture of a GEA-headstamped Flateau-style round that I cutaway (live and sectioned), 2nd from the right in the bottom row.


I assumed the “RAP” is what I know to be the “RAG”…Ring Airfoil Grenade

am I mistaken ?


Yes, the less-lethal RAG variants have been renamed the RAP. One, the projectile don’t explode, and two, no one wants the PR nightmare of trying to explain to the press why you were firing “grenades” at unarmed protesters.


DK, I forgot to ask when you posted this originally, What is the origin of the name Cyclone bullet. I have not previously heard them referred to by this name?

SBC, Your Flateau-style round is one of the Edgewood designed bullets. The 9mm Tubular load has a flat still disc below it to act as a pusher. This disc seperated when the bullet left the barrel. The nominal advantage of a tubular bullet is that the drag is significantly reduced if supersonic flow can be established through the center cavity of the bullet. Achieving this supersonic flow depends on the bullet velocity as well as the diameter of the hole and the length of the hole. The Armament Lab at Eglin AFB tried some of this in the Bay 10 facility by drilling out the standard 20mm TP projectile but the results did not show a significant improvement. Edgewook did work in 40mm and up to 105mm that I saw.

In 9mm or 38 special, there wasn’t a chance of supersonic flow so the hole had a normal shock across the front and there was little flow down the hole and no real improvement in the drag. As a result, Edgewood developed the Annular Nose Solid Base (ANSB) bullet which is the GEA headstamp load you sectioned. The box for this load is pictured below.

I know that the FBI SWAT team bought both the ANSB and the tubular loads from GEA (perhaps through the Army). The tubular loads for the FBI had a white plastic plug in the tip to make them feed better. The ANSB had a different shaped tip so feeding wasn’t a problem.

I have never heard of an ATF contract with GEA so I assume the loads that were used at Waco were obtained from the FBI but this is just a guess.

Somebody was still trying to get air flow through the center hole since I have a couple of different loads with holes in the side. One is a tubular with two holes in the side (just the top of which is visable above the case mouth and the other is a solid copper bullet shaped like the ANSB, but with three holes in the side showing just above the casemouth. These rounds reportedly came from Aberdeen where much of the test firing for the Flateau pistol projectiles was done.

Cheers, Lew


Lew - The first major use of the term “cyclone” and what was undoubtedly the catalyst for how the term was initially proliferated would mostly be due to the “Soldier of Fortune” magazine article on page 28 of the Sep 1993 issue where the subtitle to the main article title is: “Exotic 9mm cyclone round exposed”. Later on in the article it mentions the origin of the name cyclone as far as why they were using it in the article:

I’m not sure what they are referring to when they say “existence of the tubular steel bullet has been publicized before”, maybe a law enforcement mag, or FBI bulletin?

This article is the greatest, if not only source for published historical and photo documentation of this cartridge. It shows the same box label which Lew posted above, as well as another box label from G.E.A… The article carries on with amazing info such as how Findlay claimed that there were “4 calibers tested” which were .45acp, 9x19, 45 magnum, and 9mm magnum. Apparently the 45 and 9 magnums were “just to determine the bullet’s basic performance characteristics”. Interesting that he doesn’t mention the .38 / .357 loads in the article, but I had always assumed that these were the rarest samples based on what I know, and maybe not worth mention if they didn’t get any contracts for them? The article says that the .45acp tubular projectile was 116gr with an fps of 1,250, while the 9mm tubular projectile was 57.2gr at 1,600 - 1,800 fps.

Here are images (big):

Notice the Ogive variations on the versions of the projectiles below - Neat!

It continues onto pages 69 and 70, talking about how PMC unwittingly (supposedly) infringed on Flatau’s patent, how Flatau confronted them, and ultimately how they reached a licensing agreement for PMC’s short lived “Ultramag” tubular ammo.


Interesting. Ken Carter lived in San Antonio and I knew him pretty well back then. I had not seen the article.

Gas anyone ever seen a 9mmP by PMC with an Ultramag bullet. All I have seen is an advert.

Has anyone seen any Guilford labels other than the two illustrated??? I had a few of the Aberdeen/Edgewood Arsenal experimentals and they came in the normal commercial WW box with some handwriting on it.




I have previously seen this label:
which was originally posted here:
They are all for the .38 and .357 however.


The only PMC products I’ve seen with regards to this type of projectile are the early brass Ultramag in .38 Special (very yellow tint to the bullet; restricted importation/sale due to poss. AP characteristics), the commercial ‘38J’ Ultramag with tubular copper bullet, which I have a half-full box of, and the .44 Special Ultramag (copper bullet, looks like a jacuzzi!).

I carried the 38J very briefly in a backup .38 (since many .38 loads won’t expand from a very short barrel, I thought the cutting mechanism was viable…it makes ‘spaghetti’ in gel). When the Chief asked about them one day at the range, I replied “see, this way I can tell how old the perp is by using the ‘core sample’ and counting the rings”. Not sure if he got the joke.

I’ll see if I have a pic of the 38J box. The only GEA boxes I’ve seen are the ones already displayed.


MWinter. I like the line on taking a core sample!

I was passed the two attached photos of what was reported to be a 9x19mm Ultramag. Without a photo of the front of the bullet, I can’t say that I know they made one. When I cited the ad, I was confusing it with something else-the PMP RAYtrace whatever that is???

Any ideas appreciated.

Nice 38 Special and 357 boxes. I have never seen anything similar in 9mmP.

Cheers, Lew


The bullet is similar in shape to the .38 Special, the only caliber I have personally seen. It is not similar to the “bullet only” picture in their catalogs, though. That bullet had a much shorter full diameter portion that would show above the case mouth, if loaded. I don’t know if they ever load the “catalog-pictured” bullet or not.

They introduced the round first in their copyright 1986 catalog, interesting of itself because an advertising card from PMC that I have, giving the history of the round on the back, mentions the technology first becoming “openly available” in the U.S. in 1987. It may be their 1987 catalog though, because I just found that I have an earlier catalog also copyrighted in 1986.

The cartridge appeared first in the second 1986 copyright catalog in .38 special only. Unfortunately, I do not have a catalog from 1988. In the 1989, 1990 and 1991 catalogs, it is still shown in .38 Special and joined by .44 Special. The 1990 catalog introduces the “Starfire” HP from PMC.

In the 1992 catalog, the tubular rounds disappear with no mention, and are not found again in any other catalog. There was never mention of them in any caliber other than .38 Special and .44 Special.

I don’t know why they would make even experimentals without their headstamp though. Seems like a lot of trouble for nothing, since they were advertising the bullet was theirs. In favor of it being PMC is the red primer seal. In favor of it not being, the 9mm from PMC at that time had nickel-plated primer cups (although a brass primer is possible. The very first pre-production run PMC 9mm Para ammo had brass primers. Only a few boxes, as samples, appeared in the USA in November 1979, and I was lucky enough to get one of them. The rounds had brass primer cups. Most everyone who has this round got it from me. The first production run for the U.S. Market, c. March 1980, had nickel-plated cups. It is possible that PMC used brass cups for their experimental or pre-production loads, for whatever reason). Neither point is definitive and it could well be that the 9mm shown is a proto-type PMC Tubular. Whatever it is, it is a nice round. Have never seen it before.

The advertising card I mentioned gives full credit to the Abraham Flatau Ring Airfoil Grenade, by that name, as the “seeds for this ballistic breakthrough.” As with most wonder bullets, I think that were this truly a ballistic breakthrough, it might have lasted more than a few years in the PMC line. Of course, I suppose the market plays a part in that also.


Now I’m wondering about mention of a possible Israeli copy of a cyclone in 9mm? I saw the reference here: which is a summary of a Soldier of Fortune article which mentions the cyclone bullet, and appeared in an article from a month or two before the more thorough article on the cyclone which they eventually did. It mentions this: [quote]Although variations of the original design have since been made in Israel and South Korea, the FBI’s initial order was placed with Guilford
Engineering Associates in Guilford, Ct.[/quote]
I know what the South Korea reference is of course, alluding to PMC tubular, but knew nothing about an Israeli copy?