[sci.military] Muzzles of cannons

khai@adi.com (Sao Khai Mong) (04/18/91)

From: khai@adi.com (Sao Khai Mong)


On the muzzle of certain guns and howitzers, there is a
hammerhead-like attachment present.  What is the purpose of it and why
do certain guns need it and others not?

--
Sao Khai Mong:   Applied Dynamics, 3800 Stone School Road, Ann Arbor, Mi48108
(313)973-1300    (uunet|sharkey)!amara!khai   khai@adi.com

bxr307@coombs.anu.edu.au (Brian) (04/18/91)

From: bxr307@coombs.anu.edu.au (Brian)


>From: khai@adi.com (Sao Khai Mong)
>On the muzzle of certain guns and howitzers, there is a
>hammerhead-like attachment present.  What is the purpose of it and why
>do certain guns need it and others not?

	This is called the "muzzle brake".  It is basically a device which is
intended to reduce the recoil that the gun carriage/mounting recieves when a
round is fired by redirecting the gases from the barrel rearwards.  Muzzle 
brakes come in assorted shapes, functionality and efficiency.  They can range
from simple holes drilled in the barrel at the muzzle end, canted backwards,
to complex, multi-slotted devices several feet long which project from the
end of the barrel.
	You will though, see them primarily on weapons which require some
help to alleviate the force of the recoil which would normally damage their
mountings.  However surprisingly they have gone out of favour on tank guns
because of problems encounted in their becoming fouled by the discarbing
sabots of the main anti-armour round now fired which relies on kinetic energy
(usually referred to as APFSDS or APDS) to destroy its target.

Brian Ross

tarl@lectroid.sw.stratus.com (Tarl Neustaedter) (04/18/91)

From: tarl@lectroid.sw.stratus.com (Tarl Neustaedter)


In article <1991Apr18.032433.21674@amd.com>, khai@adi.com (Sao Khai Mong) writes:
> On the muzzle of certain guns and howitzers, there is a
> hammerhead-like attachment present.  What is the purpose of it and why
> do certain guns need it and others not?

The hammerhead attachement is a muzzle brake, which vents some of the exhaust
gasses along the sides rather than in the same direction the projectile is
fired. This somewhat reduces the recoil of the weapon. This reduction in
recoil is at the expense of some range and some accuracy.

The question on whether a gun needs it or not is based on how much recoil
you are willing to tolerate. In small human carried (hunting) rifles, this
brake is rarely present. In larger rifles (e.g., non-tripod .50BMG) it is
almost a requirement. For tank mounted weapons, the question would be what
the effect of recoil is on the tank itself; wear and tear on the turret
mechanisms and (for the M1Ax tanks), the effect of rocking the tanks while
in motion (I presume severe rocking could cause a tread to fall off).

No reference, this is largely a compilation of what I researched when
buying my .50 rifle, where the effects of recoil dominate the usability
of the weapon.

--
Tarl Neustaedter	tarl@vos.stratus.com
Marlboro, Mass.		Stratus Computer
Disclaimer: My employer is not responsible for my opinions.

bjohnson@athena.mit.edu (Brett W Johnson) (04/18/91)

From: bjohnson@athena.mit.edu (Brett W Johnson)


In article <1991Apr18.032433.21674@amd.com> khai@adi.com (Sao Khai Mong) writes:
>On the muzzle of certain guns and howitzers, there is a
>hammerhead-like attachment present.  What is the purpose of it and why
>do certain guns need it and others not?

It is called a muzzle brake and is designed to reduce recoil, thus 
permitting a much lighter recoil absorption mechanism.  It has some
disadvantages however, notably increasing the noise/overpressure
to the rear of the gun (where the crew is).  Also I don't think
you can fire DS (discarding sabot) rounds from guns fitted with
a muzzle break.

--
Brett W. Johnson  
These opinions are mine and mine alone...

henry@zoo.toronto.edu (Henry Spencer) (04/19/91)

From: henry@zoo.toronto.edu (Henry Spencer)


>From: khai@adi.com (Sao Khai Mong)
>On the muzzle of certain guns and howitzers, there is a
>hammerhead-like attachment present.  What is the purpose of it and why
>do certain guns need it and others not?

It's called a muzzle brake.  The purpose is to deflect some of the gases
from a firing rearward, to reduce recoil.  It's basically a kludge added
if the recoil from the gun is too heavy for the mounting platform (whatever
it is) to handle.  It is thoroughly unpopular with people like infantry
who have some reason to be near the gun while it is firing, because it
deflects the gases *towards them*.  This is a sufficient headache in
tactical use that designers avoid muzzle brakes when possible.

-- 
And the bean-counter replied,           | Henry Spencer @ U of Toronto Zoology
"beans are more important".             |  henry@zoo.toronto.edu  utzoo!henry

consp04@bingsuns.cc.binghamton.edu (Dan Boyd) (04/19/91)

From: consp04@bingsuns.cc.binghamton.edu (Dan Boyd)


khai@adi.com (Sao Khai Mong) writes:
> On the muzzle of certain guns and howitzers, there is a
> hammerhead-like attachment present.  What is the purpose of it and
> why do certain guns need it and others not?

	This is a muzzle brake, which directs the firing gases
backwards to propel the gun forwards to damp the recoil.  It makes the
gun much LOUDER.  You don't see them on guns that don't need muzzle
brakes to help absorb the recoil.  Naval guns don't have them because
the recoil is absorbed by the water.  Modern tank guns don't have them
because the recoil is absorbed by the recoil pistons.
	Water guns don't have appreciable recoil, and thus don't need
muzzle brakes.

Daniel F. Boyd
consp04@bingvaxu.cc.binghamton.edu

thos@suite.sw.oz.au (Thomas Cohen) (04/19/91)

From: thos@suite.sw.oz.au (Thomas Cohen)


In <1991Apr18.032433.21674@amd.com> khai@adi.com (Sao Khai Mong) writes:
>On the muzzle of certain guns and howitzers, there is a
>hammerhead-like attachment present.  What is the purpose of it and why
>do certain guns need it and others not?

This is a muzzle brake. Simply, it's there to divert some of the gas
that comes out of the muzzle after the shell. It turns it to develop a
forward pull on the barrel which counteracts some of the recoil.

There are problems associated in turning the gas back too far as you
could seriously annoy the gun's detachment. A good muzzle brake can
reduce the recoil forces by 25-35%. It is possible to improve on this
but usually at the expense of manufacturing difficulty.

-- 
thos cohen
UUCP: ...!uunet!softway.oz!thos
Internet:    thos@softway.oz.au

wbt@cbema.att.com (William B Thacker) (04/23/91)

From: wbt@cbema.att.com (William B Thacker)


Many readers have explained the function of muzzle brakes.  In WWII,
they were considered useful for high-velocity tank guns, in particular, 
as the reduced recoil saved wear and tear on the gun's recoil system,
optics, etc.

One drawback was that the muzzle brake tended to kick up more dust, helping
enemies locate the firing tank and reducing the tank's visibility.  For
this reason, they were sometimes omitted, especially on late-war tank
destroyers such as the Jagdpanzer IV's and the Hetzer.

They were less important for artillery, which tended to be of a lower
muzzle velocity; still, some artillery pieces were so equipped, to allow
the use of a lighter carriage.

-- 
Bill Thacker	AT&T Network Systems - Columbus		wbt@cbnews.att.com