"Rocket" bullets from Ukraine / UK


#1

Some details can be found here: http://www.stiletto.uk.com/Stiletto_Presentation2.pdf (Stiletto UK is an UK-based outlet of the Ukraine-based Stiletto Ukraine Co; at least inventors behind those patented bullets are from Ukraine)

PS I still can’t decide if its a deliberate farud or genuine stupidity naivette.


#2

Why do you think its’ a fraud? Rocket-Assisted Projectiles (RAP) have been around for a long time, but mainly in artillery calibers. Check Google and you’ll see a bunch of them, like the 105mm M548 and M193 and the 155mm M549 and M549A1. MBA’s Gyrojets failed in part because of the very low muzzle velocity as the 100% rocket-powered projectile was accelerating in the gun’s barrel, only gaining full velocity at some distance downrange. But Stiletto’s “rocket bullets” would have a high muzzle velocity because they are fired in a standard cartridge case.

One advantage of MBA’s Gyrojets was that they continued to accelerate after leaving the gun’s muzzle and as a result, had a much higher velocity (energy) downrange, about twice that of a .45 ACP at the same rage. It seems at least possible that the Stiletto might have the best of both: a high muzzle velocity and a high downrange velocity.

The Stiletto bullets have just one exhaust port. They don’t need multiple angled ports like Gyrojets because they are stabilized by the barrel’s rifling. But that illustration on page 36 of the .pdf sure looks like a large caliber Gyrojet with six nozzle ports around a central primer. Anyway, this deal may not work out in the market, but it might be a little soon to label it a fraud.


#3

I think it’s a fraud or stupid dersign because I consulted with professional who was previously engaged with design and manufacture of small arms ammunition, and he said that this design has nothing to do with “rocket”, because it is intended to be fired from standard rifled barrel. if you will compare closely the size of the exhaust nozzle on the 9x19 bullets above with overall cross-section of the Gyroject nozzles, you’ll note that “rocket” effect is more of a wishful thinking, and their claimed muzzle velocity of 600m/s can be achieved only via standard “active” (as opposed to reactive) ballistic launch.
Furthermore, the same copmany (their Ukraine-based HQ) makes certain claims about their other ammunition designs, which sound exactly like BS, such as tungsten-core projectile for 7.62x51 NATO cartridge that can penetrate all known types of body armor at the ranges of up to 1300 meters, (page 23)


#4

I am not sure if it is all that easy to judge just by looking at the outer appearance.
As the board is showing they are/were using different nozzle designs. Also we need to look at the intended bruning time of the secondary charge which must (only) meet the flight time of the bullet which is only the fraction of a second.
The patent states that propellants with different burning rates are used (what I would have expected).

I’d like to see the Vo, V100 and V200 before I would express any thoughts.

Here the patent:

RU2372581C1.pdf (635.3 KB)


#5

There are also “fuming” and other drag reducing methods to increase range and velocity down range.

Cant see it being useful on 9mm though out of pistols.


#6

The bullet makes more sense now, given that it contains the powder for the round, possibly trapping the burning gasses for a bit longer after the bullet exits the barrel. Maybe an effective 1" of length?


#7

note that to achieve claimed MV of 600 m/s it has to generate quite high initial pressure; with bullet’s walls that thin they will greatly increase friction in the bore under such pressure (and might as well tear up the rear part with the nozzle if the bore is “rough”), and the nozzle has to be very big as not to be blown up upon initial launch. Also, internal space is very limited to contain any useful amount of “rocked” fuel in front of the initial propelling charge. Finally, rocket fuel might suggest attempts to increase effective range; but bullet has necessarily high cross-section when seen from the side, so in combination with relatively low weight the wind drift has to be unusually high and BC unusually low.


#8

Here the V is also generated outside the barrel so I wonder about the gas pressure which (hopefully) should be within CIP or Mil standards.
Wind drift is also a question of flight time what brings us to the V.
As mentioned I would like to see the V-curve maybe up to 300m to be sure.

It is difficult to discuss or even judge on something without having all the data.
Even then I would leave the final judgement to ballisticians.


#9

Just a reminder some of the Stiletto material has been mentioned before: http://iaaforum.org/forum3/viewtopic.php?f=8&t=13669


#10

Very interesting. I agree that it isn’t a “Rocket” which typically requires a significant static pressure differential across the nozzle to function with any effect.

Rather this is based on the work of Heinrich Langweiler and was originally entitled the “Impuls Antribe” or Impulse Propulsion Theory. Mr Langweiler was also the inventor of the" Panzer Faust".

The concept was basically to accelerate the propellent down the barrel with the projectile instead of burning it in the case when the gases then must accelerate down the barrel to apply pressure to the base of the projectile. Part of the concept was to minimize the need for combustion gases to travel down the bore and create a level pressure profile down the barrel rather than a profile that required high chamber pressure with the pressure dropping off as it reached the base of the bullet. .

The “Langweiler Principle” was the foundation for the German WWII 9mm “Rocket” or “S-Munition” rounds. I have written articles on these in IAA Journals 472 and 475. You can find quite a bit of the source data on this subject at my webpage at gigconceptsinc.com. Go to 9mm Ref Info, and the to 9mm Rocket Source Data.

These rounds are interesting, and very similar to rounds tested by a Slovak inventor beginning about 8 or 9 years ago. I pictured some of them in the thread bdgreen references. The items pictured in this thread are not in my collection. Below are some of the Slovak items I have acquired.

The similarity of these two efforts argues against them being independent efforts.

Cheers,
Lew