The South African “Monad” cartridge was discussed in a IAA Forum thread beginning July 20th, 2009, titled “Unknown 9 mm.”
It is also covered well in a Monograph from the South African Cartridge Collector’s Association entitled simply 9 mm Parabellum (this seems to have been part of a much bigger work on RSA cartridges since the pages numbers show Pages 168 to 218, but all I have is the 9 mm portion).
Much of the below was taken directly from the above work, and from Will Reuter’s fine article on the Monad Story.
The Monad cartridges were designed by Andre Van Dyk, while he was working at PMP (Pretoria Metal Pressings). All of the Military/Police types of his designs, The Monad projectiles,
were produced at PMP and appear in cases with their headstamps, primarily of the military type and with at least the exception of one made for Taiwan, discussed later. Later designs very much related, although different in bullet construction, were made after Van Dyk left PMP and became a principal in the New Generation Ammunition Co. in 1992.
The requirements of the original Monad bullets were to penetrate targets such as steel, wood and glass but still have a sever wounding effect after penetration. Short range with high wounding potential. Deflection was to be minimal. Accuracy was to be good while staying within the requirements of the Hague Convention of 1899. Applications for this ammunition include hostage situations, riot control, urban crime prevention, in crwoded situations where a selected target is to be eliminated, in situations where the target is hidden behind cover such as a verhicle and moving vehicle immobilization, etc. The Monad design was based on the French Tres Haut Vitesse cartridge, heavily modified.
Specifications: Bullet is made of copper, with a weight of 3.2 to 3.5 g (grams). Velocity is about 575 m/s with a chamber pressure of 270 Mpa. Accuracy is less than 76 mm at 25 m. Most come with blue tips but the customer can specify the color.
Packaging: 25 rounds per box, 16 boxes per PVC bag and 8 bags per crate.
One of the earlier types has a W-W headstamp, but with its very small headstamp print, the headstamp is obviously spurious,spurious, and now known to be made in South Africa by PMP, and certainly not made by Winchester. There is one with the headstamp “NPA 67,” pictured along with its box, made for the Taiwan Procurement Agency (police).
The Monad types use a projectile with hollow base. One of the major differences of the later designs made by New Generation are that they have a solid, flat base projectile. Most of those with red plastic tips, and are loaded in any brass available, including IMI and Norma. The round we have with Norma headstamp has a black tip. Some of the early ones in RSA military-style headstamps, true Monad types, have no plastic cap at all. Other Monad types have a blue plastic tip. Many colors have been made experimentally, and the NPA-headstamped Monad round at hand has a cream-colored tip.
Also present in our own collection are three rounds with nickeled-brass cases. One with an NGA headstamp has a red plastic cap, but another nickeled-case version with IMI headstamp has a cap of black plastic, as does another nickeled-case round with PMP commercial headstamp. While one round pictured in the monograph with headstamp “NPA 97” has a blue cap, our own round with this headstamp has a cream-colored cap, and is definitely a Monad.
Bullet ogives run from those with quite pointed plastic noses through some with a very blunt, round nose ogive. Most of the rounds have brass primer cups, but several, including two of those with nickeled cases have nickeled primer cups.
Early NGA Technical bulletins refer to their projectiles as “The liminator Bullet,” but later literature from that company calls it “The Sentry Bullet,” perhaps a name change made on the basis of political correctness. Black-plastic bullet tips were also eliminated, reportedly for the same reason. Their literature refers to tests made at New Generation Pty Ltd. (up to 1994 call “New Generation Ammunition cc”).
Regarding the use of the plastic cap, NGA literature indicates that it is only there to improve feeding in self-loading firearms, and the facilitation of fast reloading of revolvers either by hand or with speedloaders. They do not seem to make any claims for actual improvement in exterior or wound ballistics attributed to this cap.
In the technical bulletins, the powder shown used in rounds shown within their ballistics tables are Powder No. 200, made by Somchen RSA.
New Generation ammunition has been found in 50-round plastic boxes, although other packaging is likely to have been used as well.
This is a summary of about all the information I have. It is not in-depth coverage of the dozens of variations known in the Monad and the New Generation Sentry cartridges. It is simply a brief overview in an attempt to provide those with a casual interest in this subject with some idea of these rounds. We have not pictured them, as a previous thread provides those interested with pictures of many of the variations of Monad and New Generation types.
We apologize for any confusion that the original form of this effort probably caused. We also thank Jon for a copy of the article that allowed us to make many corrections to our original answer.
NOTE: Heavily edited from the original answer to correct and complete some information, and to correct the usual typographical errors that plague my quickly type answers these days.