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recoil question part 2
bobski
Member Posts: 17,868 ✭✭✭
excercise manners.
now lets continue....
Q: where does recoil or (action reaction) begin?
a. at the muzzle.
b. at the shell base.
c. at the recoil pad.
in other words, where does the shot and gun move away from each other?
now lets continue....
Q: where does recoil or (action reaction) begin?
a. at the muzzle.
b. at the shell base.
c. at the recoil pad.
in other words, where does the shot and gun move away from each other?
Retired Naval Aviation
Former Member U.S. Navy Shooting Team
Former NSSA All American
Navy Distinguished Pistol Shot
MO, CT, VA.
Former Member U.S. Navy Shooting Team
Former NSSA All American
Navy Distinguished Pistol Shot
MO, CT, VA.
Comments
Some short barreled guns, such as a coach gun, riot/trench, some hunting models that have barrels shorter than 24 inches don't get the benefit of a complete powder burn before the shot leaves the muzzle, one of the reasonsons they seem to "bounce" more.
Regards Dave
like a rocket leaving earth. it starts at the pad, and continues until the rocket shuts down. if the pad wasnt cemented to florida, it would go to china at the same speed.
thus...a 3 dram burn is longer than a 2 3/4 burn and a 3 dram load creates more reaction into your arm.
viloa...recoil.
guns are designed to soften that felt recoil. they have:
recoiling bbls
thicker pads
hydro shok systems
heavier guns...(OW, YOU PAYING ATTENTION?[:D])
mercury recoil reducers
etc...
so, after millions of rounds expended, i can say with some certainty, a 1 1/8oz lead-2 3/4dram load is SOFTER than a 3 dram-1oz load.
now, as you were eluting to in your orginal question, steel, bimuth, lead....the key to recoil is the dram equivilant.
ive shot international 2 3/4 dram 1oz loads loaded to 1450 fps and they kick less than 1205fps 3 dram 1 1/8oz trap loads. muzzle velocity and choke has nothing to do with it.
so, that gun is pushing at your arm way before the shot hits your choke. its why some guns with simple actions kick the begezus out of you. and too, when someone blows a bbl muzzle off. what direction does it fly? yep...away from you. so, logically, steel shot hitting a full choke is actually taking some of the recoil away from your arm because the gun bbl wants to go with it out the muzzle in the opposite direction from your arm.
dram load, gun design, and bbl length determines recoil. see OW's excellent post on bbl lengths and new loads.
its my opinion and im sticking to it. my trophies speak for themselves.[^]
Former Member U.S. Navy Shooting Team
Former NSSA All American
Navy Distinguished Pistol Shot
MO, CT, VA.
quote: muzzle velocity ..... has nothing to do with it.
.......dram load, gun design, and bbl length determines recoil.
While your at it, PROVE that a 3 dram 1 1/8oz load 1200fps that uses 5gr of powder X kicks exactly the same as a 3 dram 1 1/8oz 1200fps load that uses 25gr of powder Y.
I'll rephrase my original statement, you wont get maximum recoil until you achieve a complete powder burn. From what I've read powders used for lead shot, that's about 25-26 inches in barrel length. About 24 inches for the steel loads. Anything shorter, you lose FPS and penatration ability do to the fact the complete energy transfer didn't have time to take place. Like I said earlier, there is a reason you din't see hunting/target shotguns with barrels shorter than 26 inches, just an occasional 25 inch, prior to steel shot.
Bobski if you need a 9 lb gun to shoot 3/4 oz skeet loads,(28ga) you must be a small guy. My 28ga Md 12 is like shooting a cap gun! But then again I remember going through a couple boxes of 1 7/8 oz lead magnums in the duck blind too! LOL
Good read here!
Regards to all
Dave
Bodies at rest tend to stay at rest.
While the law "for every action there is a direct EQUAL and opposite reaction" is always true, what we have in the case of a firearm are vastly different masses. Yes, as soon as the pressure increases due to the burning powder, recoil starts. However, due to the greater weight (mass) of the firearm / shooter combo, the firearm (shotgun in this case) doesn't "move" until the projectile (shot/bullet) is well clear of the muzzle.
The 1 1/8 oz shot leaves the barrel at approx 1450 feet per second
The 7.5 POUND Shotgun and 180 POUND (?) shooter aren't going to accererate at more than 390 feet per second^2
But because we resist that acceleration, we FEEL recoil
It's ALL about energy - and a larger charge of powder, all other things being equal (Oh, how I love to use that phrase) creates more energy that the shooter needs to resist (absorb?)
trophies dont lie.[8D]
oh come on OW, so you answered wrong. its ok! we wont tell bert.[:D]
havent you guys ever shot a squib before? did it hurt? course not. payload has nothing to do with it. it the powder charge that hurts.
Former Member U.S. Navy Shooting Team
Former NSSA All American
Navy Distinguished Pistol Shot
MO, CT, VA.
First of all, the beginning of recoil is not a place - it is a force that is generated from a complicated set of events. That is why recoil can be measured in units of kg-m/s or foot-pounds and not meters or inches. Recoil is the backward momentum of the gun which is equal to the forward momentum of the projectile and ejecta, which is gas from the burned powder and wadding. Both the forward momentum and the backward momentum are equal M = -M. The bullet has the same momentum as the recoil, otherwise you would go flying.
Mg*Vg = Mb*Vb + Mc*Vc
Where:
Mg,Vg = mass and velocity of the gun
Primary Recoil = Mb,Vb = mass and velocity of the bullet
Secondary Recoil = Mc,Vc = mass and velocity of the powder charge (burned gases/wadding)
Also people that are struck with bullets do not go flying through the air or through windows because there isn't enough momentum. The flying thing is a Hollywood invention that defies physics. If this were the case the shooter would also be thrown flying through the air.
It would be more correct to say, "Where is recoil felt or when does recoil occur?"
When a gun is fired the gas from the burning powder forces the bullet out of the case and down the barrel and exerts an equal and opposite force on the breech and stock. If the gun weighed the same as the bullet it would recoil back just as fast as the bullet goes forward. However, the gun weighs much more than the bullet and powder charge so the bullet is moved much faster and farther than the gun.
Actually, there are three elements that produce recoil. The first is the reaction to the acceleration of the bullet as it moves down the barrel until it leaves the barrel at it's maximum velocity, commonly referred to as muzzle velocity. The second element is the reaction to the acceleration of the expanding gas generated by the burning powder. The third element is the reaction of muzzle blast when the bullet leaves the barrel and the escaping gas gives a rearward push to the muzzle. That is when recoil begins. And recoil occurs over time - it is not and instantaneous event. If the force of recoil were plotted as a velocity on a graph there would be a rise and fall time of the velocity. However, recoil is not instantaneous, but it is very fast because none of us can sense the increase and decrease of velocity.
As a general rule of thumb, the escaping gas velocity is about one and a half times the bullet velocity. For example, the escaping gas velocity would be about 4,000 f.p.s. for a projectile with a muzzle velocity of 2,700 f.p.s. Therefore, this is where the majority of the recoil comes from.
Where is the bullet when the slide starts to open on a 1911?
A. In the cartridge case
B. In the barrel
C. Out of the muzzle
Why does the slide open then?
Think about it. John Browning figured it out and he never studied physics.
I hope this helped clear up this discussion, rather than complicate it.
Regards,
Heavyiron
"Blowback is a system in which automatic or semi-automatic firearms operate through the energy created by combustion in the chamber and bore acting directly on the bolt face (a place) through the cartridge. Other operating systems are recoil operation, gas-actuated, gatling and chain.
In the blowback system there is no positive lock between the bolt and the barrel. The mass of the bolt and force of its recoil spring act to keep the breech closed. The expanding gases from the fired round overcome this inertia and "blow back" the breech. The breech must be kept closed until the round has left the barrel and gas pressures have subsided. The weight of the bolt is the major factor in determining this, and to remain practical this system is only really useful for firearms using relatively low pressure rounds. Pure blowback operation is typically found only on semi-automatic small-caliber pistols and automatic submachine guns.
For more powerful rounds and for lighter operating systems, some form of delayed or retarded blowback can be used, in which the bolt has to overcome some initial resistance while moving."
Further to add support to heavyiron's post:
http://www.bsharp.org/physics/stuff/recoil.html
However, not all recoil is linear, some of it is angular (and I don't really want to start doing free-body diagrams on this (at least not tonight))