Vented bullets

#5
Venting round a bullet (or other projectile) would normally allow bypass of gas in the bore, resulting in lower muzzle velocity - this technique has been used before to launch two projectiles at different velocities.

Unless of course they are also playing some tricks with the burn of the propellant itself...

Edited to add: Just re-read the article, and it seems even more confusing - I can't see how it would act as a muzzle brake if the gases are acting on the bullet, not the muzzle!
 
M

Mark The Convict

Guest
#6
Would the (presumably minor) reduction in recoil be worth the stuffing around, and wouldn't the vents increase drag?
 
#7
Would the (presumably minor) reduction in recoil be worth the stuffing around, and wouldn't the vents increase drag?
Agreed! It would certainly increase the manufacturing costs and therefore the procurement cost. The British Army would then have even less recources for training and operations. It might be OK for specialist roles such as sniping, if accuracy is not affected, but as general purpose SA round, I don't see it.
 
G

goatrutar

Guest
#8
Not really sure the idea is even worth doing in those calibres. Maybe for .50 it might be worthwhile?
 

jim24

LE
Book Reviewer
#9
Sounds a bit like the Gyrojet bullets used by James Bond in You only live Twice, I seem to remember they were tiny rocket projectiles though, with no recoil.
 
#11
This looks like a load of bollox..

The only effect of the perforations would be to bypass the breech seal and allow the venting of the charge. The only reason to do this would be to reduce the energy of the projectile. I suppose you could do this to reduce a supersonic round to subsonic for silencing purposes, but simply reducing the charge would do this just as well..

Venting the charge sideways as the bullet emerges from the barrel could (I suppose) increase the velocity slightly as the exiting gas would act longer on the bullet base, but I would imgine this would not compenste for the loss of energy in the barrel due to gas leakage. If the holes were canted, you might be able to increase the spin rate, but again I would think this marginal as it would happen for only a fraction of a second. As someone has already pointed out, I would also suspect this would cause breech erosion problems..

I suspect Little Jonny has been playing with his dad's CNC lathe...

however if DS Ammo at Shriv is watching.. could be a good POTATO project!
 
#12
I may be totally off the mark here, but I thought the Geneva Convention banned certain types of round, including ones with holes in them due to the increased fragmentation when they hit bone and flesh?
 
#13
I may be totally off the mark here, but I thought the Geneva Convention banned certain types of round, including ones with holes in them due to the increased fragmentation when they hit bone and flesh?
I think you mean the Haig protocalls...

No - only rounds "designed to expand in order to increase wounding effect" are proscribed.. Any half decent lawyer could drive the proverbial coach & horse through if they want..
 
M

Mark The Convict

Guest
#14
There's a thread around here somewhere about various 'experimental' types of .303 ammo that was produced during WWII, partly IOT increase its terminal effect. Copperplated chalk, wooden-tipped rounds, aluminium-based rounds...all rather inventive.

AUIU, the fact that these non-traditional cores were encased in a standard copper jacket made them quite legal, but their effect on target was rather more savage than usual ball ammo. That 'Box O'Truth' bloke test-fired some of this ammo, and it not only burst the water jugs, but blew the sides out of the box, IIRC (!)
 
#15
I may be totally off the mark here, but I thought the Geneva Convention banned certain types of round, including ones with holes in them due to the increased fragmentation when they hit bone and flesh?
I think it is the Hague Convention. I suspect there is something more to this than is obvious. The claimed benefit, reducing recoil, doesn't seem to be achievable within any of the laws of physics that we know of. I'd suspect that there is some other feature that they're not publicising, e.g., maybe it yaws all over the place on impact with tissue, making it grotesquely lethal, but still legal if the claimed purpose of the holes isn't to cause the bullet to distort. I think some reading of the invisible print between the lines may be required.

The holes would increase drag and reduce range

PS

No - only rounds "designed to expand in order to increase wounding effect" are proscribed.
Any half decent lawyer could drive the proverbial coach & horse through if they want..
That comment wasn't there when I started my reply, but yes, that seems to fit. So not ' designed to expand in order to increase wounding effect', oh no, M'lord, certainly not.

Any tendency to tumble all over the place is purely an unintended by-product of the design.
 
#16
Sounds a bit like the Gyrojet bullets used by James Bond in You only live Twice, I seem to remember they were tiny rocket projectiles though, with no recoil.
Gyrojet was an interesting one. The rocket-powered ammo cost an arm and a leg but the weapon itself cost next to nothing. It didn't have to handle any significant firing stresses so it could be made out of monkey metal. I've never seen one up close but I wouldn't mind having a little play to see what it's capable of.
 
#17
Gyrojet was an interesting one. The rocket-powered ammo cost an arm and a leg but the weapon itself cost next to nothing. It didn't have to handle any significant firing stresses so it could be made out of monkey metal. I've never seen one up close but I wouldn't mind having a little play to see what it's capable of.
Capable of blowing your arm off. They were death traps.
Gyrojet - Wikipedia, the free encyclopedia
" Versions of the Gyrojet that were tested suffered from poor accuracy, cumbersome and slow loading, and unreliability (at best, a 1% failure rate was suggested; users quote worse figures, with many rounds that misfired the first time but later fired). "

So, given a basic combat load of,say, 100 big, fat explosive slugs in your webbing, AT LEAST one will be a blind with a tendency to reignite later. If it didn't wander off sidewise. Niiice...


Nervous looking bloke firing one here.
Shooting two rockets from the GyroJet pistol! (Camera 2) - YouTube
 
#18
Gyrojet was an interesting one. The rocket-powered ammo cost an arm and a leg but the weapon itself cost next to nothing. It didn't have to handle any significant firing stresses so it could be made out of monkey metal. I've never seen one up close but I wouldn't mind having a little play to see what it's capable of.
I have handled gyrojet guns, and yes they were just cheap whitemetal castings..

The ammunition costs would have come down if they had ever gone in to serious production. The technology was easily implemented on conventional commercial ammunition manufacturing equipment. The round was essentially a modified tracer bullet. You start with a long draw bullet jacket with a lead tip, followed by a propellent grain and closed off with a base disk holding a conventional primer cap and a series of angular holes. The base disk was then swaged over in the conventional manner.

You fire the round by hitting the front with a swinging hammer, forcing the primer on to a fixed striker. The cap fires, igniting the propellent grain and starting off the projectile, forcing down the hammer out of the way and recocking it for the next shot.. The barrel was smoothbore and sidevented all the way down. The bullet accelerated both in and out of the barrel, being spun up by the canted vents.


The problem with the gyrojet, as with all free flight rockets was down to accuracy. Rockets are very prone to errors in the launch phase, which is very slow compared with conventional ammunition (though the story that you could stop a bullet by sticking your finger in the muzzle is probably myth..). The accuracy was also badly affected by variations in the burn time of the propellent.

There was some suggestion at the time (late 60's) that the GJ would make a good "space weapon" and that some funding came from the US Govt for this. A bit "Dan Dare" IMHO - conventional rifles would probably do just as well (ie not well at all)

Editied to fix a sticky "A" key..
 
#20
There ws some suggestion at the time (late 60's) that the GJ would make a good "space weapon" and that some funding came from the US Govt for this. A bit "Dan Dare" IMHO - conventional rifles would probably do just as well (ie not well at all)
Ooooh.... sounds like an interesting new thread. Why wouldn't conventional guns work well in space? Only problems i can think of are minor (a) need to seal the unfired round properly so that exposure to vacuum won't pull the bullet out (b) the space marine will have have a way of offsetting the recoil impulse, so that he doesn't head off into space.

Otherwise, you appear to have some advantages: no air resistance, and no (at conventional firearms range) bullet drop due to gravity. I can see a future market in space tourism for fanatical bench-rest shooters who want to eliminate pesky gravitational drop...
 

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