Can two bullets occupy the same barrel...?

[redneckmedic]

Can two bullets occupy the same barrel...?


... at the same time,
... both in constant motion,
not malfunctioning, i.e. doing what they are designed to do,
in an existing weapon?

I'm not looking for a hypothetical.... "well if we make the barrel long enough and the rate of fire fast enough, anything is possible.", answer.

I'm asking, is there a machine gun that fires so quick that bullets are in the barrel at the same time?

I'm guessing the math won't work, even in a very very rapid ROF rifle, the first round at a few thousand fps is long gone even in a 2000 RPM gun.

But what if, what would happen? Would bullet two create a reverse draft and push bullet one faster? Would the increase of pressure from an occupied barrel cause a "clogged" barrel reaction even though its pulling a vacuum?

Where's INGO's Elite... the brains on the board....

 

[jd4320t]

My brain makes me think the pressure from the front bullet would hold up or stop the second.

 

[buford t justice]

The way you have it posted it sounds like two questions first is it possible and second what would happen if it were possible.
1. It does not sound possible to me with current single barreled machine guns as the bolt has to make a complete cycle back and forth an the firing mechanisim has to re cock and the firing pin has to fall to set off another round.
The gun may do all these things very fast but not fast enough to put 2 bullets in the barrel at the same time.

2.As for the question of what would happen I wouldn't want to speculate, I am not that schooled in physics.

 

[redneckmedic]

My brain makes me think the pressure from the front bullet would hold up or stop the second.

My first thoughts too... but aren't the gases moving foward at the same rate from the first bullet as the second, as to not create a "pressure wall"?
Minus the thought of the little extra friction loss the first bullet has the the second doesn't until it fully engages the lands.

 

[bluto67]

don't know if both bullets are in the barrel at the same time but shotgun news just did a write up about hyper burst. one squeeze of the trigger results in two shots that happen so quickly it only sounds like a single shot was fired. the idea is to get two impacts in the same area while still maintaining accurate shot placement. i'll have to grab that issue here and re-read it real quick like.

 

[KDUBCR250]

Being that the average time a bullet is in the barrel is .002 seconds in a average rifle the real question is is there any way a mechanical machine gun could even have time to chamber and fire another round ? The Metal Storm seem to be able to have more than one bullet in the barrel at a time Metal Storm - Wikipedia, the free encyclopedia

 

[redneckmedic]

s is there any way a mechanical machine gun could even have time to chamber and fire another round ?

Yeah, I'm guessing that is the real question... and the answer is most likely no, now to the second question

 

[Chase515]

I would think that the mechanics of the firearm will never be faster than the bullet. If the second round goes off and the other bullet is in the barrrel wouldnt it stove pipe?

 

[KDUBCR250]

The Metal Storm seems to be able to have more than one bullet in the barrel at a time Metal Storm - Wikipedia, the free encyclopedia From the link

• High barrel pressures were noted in early testing when multiple shells were 'fired' so rapidly that the second (and subsequent) shells were in motion within the barrel before the first had left the muzzle of the gun. While this resulted in very high muzzle velocities it also (appeared) to cause concern about barrel wear and barrel integrity. Metal Storm took out a patent on a barrel pressure relief valve system, but has concentrated in recent years on the development of low pressure 40 mm systems, and has in recent demonstrations deployed a microchip at the barrel muzzle which detects the passage of each projectile and locks the firing mechanism (of each subsequent shell) until the first shell has cleared the muzzle. This still allows for much higher rates of fire than conventional weapons, but appears to guard against unintended high pressure situations in the barrels.

 

[jblomenberg16]

My first thoughts too... but aren't the gases moving foward at the same rate from the first bullet as the second, as to not create a "pressure wall"?
Minus the thought of the little extra friction loss the first bullet has the the second doesn't until it fully engages the lands.

Keep in mind that the gasses in the barrel are expanding to "push" out the first bullet. So, there would be a very high pressure in the barrel that would be acting against the second bullet.

It probably wouldn't stop it, but my guess would be an over pressure and bulge of the barrel (unless infinitely strong) as you'd be momentarily trying to compress the gasses already under very high pressure in the barrel.

 

[45-70]

Only if you're Bob Munden

http://youtu.be/DcZHVspVIDs

 

[buford t justice]

Keep in mind that the gasses in the barrel are expanding to "push" out the first bullet. So, there would be a very high pressure in the barrel that would be acting against the second bullet.

It probably wouldn't stop it, but my guess would be an over pressure and bulge of the barrel (unless infinitely strong) as you'd be momentarily trying to compress the gasses already under very high pressure in the barrel.

That being said the spring pressure on the bolt wouldn't over come the the pressure in the barrel.

 

[redneckmedic]

Keep in mind that the gasses in the barrel are expanding to "push" out the first bullet. So, there would be a very high pressure in the barrel that would be acting against the second bullet.

Wouldn't a large portion of those gases be purged when the bolt opened for ejection?

 

[ckcollins2003]

Can two bullets occupy the same barrel...?


... at the same time,
... both in constant motion,
not malfunctioning, i.e. doing what they are designed to do,
in an existing weapon?

I'm not looking for a hypothetical.... "well if we make the barrel long enough and the rate of fire fast enough, anything is possible.", answer.

I'm asking, is there a machine gun that fires so quick that bullets are in the barrel at the same time?

I'm guessing the math won't work, even in a very very rapid ROF rifle, the first round at a few thousand fps is long gone even in a 2000 RPM gun.

But what if, what would happen? Would bullet two create a reverse draft and push bullet one faster? Would the increase of pressure from an occupied barrel cause a "clogged" barrel reaction even though its pulling a vacuum?

Where's INGO's Elite... the brains on the board....

If you want to get technical, yes, there are plenty of firearms where there are 2 or more projectiles in the barrel at the same time. When shooting buckshot or birdshot, there are multiple projectiles in the barrel at the same time.

 

[redneckmedic]

If you want to get technical, yes, there are plenty of firearms where there are 2 or more projectiles in the barrel at the same time. When shooting buckshot or birdshot, there are multiple projectiles in the barrel at the same time.

I didn't say shot or projectiles, I said bullets. So yes lets stay technical

 

[bluto67]

here is a bit from that hyper burst article. Shot Gun News Aug. 22, 2011

"the one company which has produced a rifle capale of hyper burst is Izhmash JSC of Russia with the 5.45x39mm AN-94 "Nikonov"."

"when set on two-shot burst, it fires at an extremely high cyclic rate of approximately 1800 rpm."

"what follows are the basic of its operation: when the first round is fired, the entire barreled receiver assembly begins to recoil rearward. as the bullet passes the barrel's gas port a small amount of gas is tapped off. this forces the bolt carrier to the rear within the already rearward moving barreled receiver."

"the bolt unlocks and the empty is ejected while simultaneously a round is stripped from the magazine and placed in a feed tray by a cable and pulley system. when the bolt reaches the end of its rearward travel it returns forward, chambers and fires the second round."

"the two projectiles travel down range approximately 27 meters apart. Meanwhile, the barreled receiver assembly is still moving to the rear. the magic of the system is that the second round is fired before the barreled receiver assembly ceases rearward travel and the recoil impulse is transmitted to the rifleman."

 

[ckcollins2003]

I didn't say shot or projectiles, I said bullets. So yes lets stay technical

Aww... I thought all lead projectiles coming out of a firearm were considered bullets. Got me all excited

Well, okay, lets get technical then. I'll even volunteer to do the math. What firearm has the highest rate of fire, slowest moving round, and longest barrel? That's the first thing to figure out.

Edit: just did the math for a basic .45 round rated at 750 ft/s. You'd need a 75 foot barrel with 600 rpm rate of fire.

Even if you bump it up to 800 rpm you'd need a 56.39 ft barrel to have one at the beginning of the barrel while the other is at the end.

Fact is... the bullet is moving too fast to still be in the barrel while another is fired.

I'm not the best at math, but I think I broke it down pretty good.

750 ft/s*12=9,000 in/s.
800 rpm/60=13.3 rounds/s
9,000/13.3=676.69 in. apart
676.96/12 in=56.39 ft.

My brain is now tired... if there are any mathematicians who can check this and make sure it is right I'd appreciate it.

 

[bluto67]

did a little math of my own. using the An-92 from the article with Tula 5.45x39 60 grain ammo.

An-94 barrel length = 15.9 inches
An-94 cyclic rate = 1800 rounds per minute
Tula 5.45x39 muzzle velocity = 2936 feet per second

2936 fps x 12 inches = 35232 inches per second
15.9" barrel / 35232 ips = 0.00045 seconds per round in the barrel
1800 rpm / 60 seconds = 30 rounds per second
35232 ips / 30 rps = 1174.4 inches between each round - NO GOOD
(1174.4" / 39 " = 30.1 meters. the article supposed around 27 meters between rounds downrange)

in order to have 2 rounds within the 15.9" barrel at the the same time the the goal is to find a round per second speed which places those rounds 15.8" apart or less.

35232 ips / 2230 rps = 15.799" between rounds
2230 rps x 60 seconds = 133800 rounds per minute

i think i may have figured everything right, but please feel free to review my numbers and point out and corrrect any errors. at any rate, it seems that getting two rounds in the barrel of a rifle simultaneously would require a ridiculous rate of fire. that rate of fire doesn't even address the physical effects of the second bullet possibly compressing the gases from the first round fired and two separate pressure waves inside the barrel causing barrel damage or failure.

 

[LionWeight]

Sounds like a job for myth busters or red jacket to me. Maybe that's why they use multiple barrels on chain guns in addition to keeping the barrels from melting.

 

[shooter521]

Maybe that's why they use multiple barrels on chain guns in addition to keeping the barrels from melting.

A "chain gun" only has one barrel. You're thinking "Gatling gun".

Chain gun - Wikipedia, the free encyclopedia

A technicality, yes, but this IS a technical discussion!