When is recoil felt?

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superstring
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Joined: Thu Sep 09, 2004 4:16 pm
Location: Victoria, BC Canada

Re: subject of post

Post by superstring »

2650 Plus wrote:I really pulled a brain flatuation just as I was finishing my thought but I still got something out of the mistake. The lurker is still on the net and correcting. spelling and mis statements .You do well on the rules, but i can't find any of your posts that deal with shooting skills. Good lurking Bill Horton
WTF????
Guest

Post by Guest »

Bill, some brain flatulence!

If my reaction times were .33 hundredths of a second (that's 3.3 thousandths!), I think I'd be a fly, not a human. An errant factor of 100, I think.
mrcameltoe

Great Adult Sites

Post by mrcameltoe »

hjk

Re: When is recoil felt?

Post by hjk »

ausdiver99 wrote:Is recoil in the form of muzzle displacement from the original state noticed as the projectile leaves the barrel (or shortly after it does) i.e having no effect on the trajectory or is it progressively felt as the projectile accelerates down the barrel? Years ago a rifle shooter told me it was the latter but I am not so sure that I agree with him.
An everlasting controversy, caused much by misunderstanding/confusion about principal physical concepts.

Recoil: "ausdiver99", do you meen recoil FORCE(acceleration), recoil VELOCITY, or total MOVEMENT of gun/shooter caused by the recoils forces(angular and/or translational)?

Without clarification your question cannot be answered properly. Simply stated. Sorry about that.
luftskytter as guest

Post by luftskytter as guest »

Simple quick and easy test that I sometimes do:
Shoot handheld and compare to shooting with grip resting on table.
Even PCP AP will show different points of impact due to recoil.
Might be interesting to see what happens with Steyr LP10 etc. with the recoil compensating moving weight.
K60 in Aus

Re: When is recoil felt?

Post by K60 in Aus »

hjk wrote:
ausdiver99 wrote:Is recoil in the form of muzzle displacement from the original state noticed as the projectile leaves the barrel (or shortly after it does) i.e having no effect on the trajectory or is it progressively felt as the projectile accelerates down the barrel? Years ago a rifle shooter told me it was the latter but I am not so sure that I agree with him.
An everlasting controversy, caused much by misunderstanding/confusion about principal physical concepts.

Recoil: "ausdiver99", do you meen recoil FORCE(acceleration), recoil VELOCITY, or total MOVEMENT of gun/shooter caused by the recoils forces(angular and/or translational)?

Without clarification your question cannot be answered properly. Simply stated. Sorry about that.
KJK, it says it all in the first few words..."muzzle displacement from the original position". Sounds pretty clear cut to me. The hypothesis is that the muzzle displacement is completely irrelevant for a single shot psitol in a slow fire event IF the projectile has LEFT the barrel at the time that the muzzle COMMENCES its movement (i.e. that the movement of the muzzle will have zero impact on point of impact). The rationale for the question: are muzzle brakes just an outlet for hot air (hehehe) and another way to get a few dollars out of shooters?

Over to the Einsteins....
hkj

Re: When is recoil felt?

Post by hkj »

K60 in Aus wrote: The hypothesis is that the muzzle displacement is completely irrelevant for a single shot psitol in a slow fire event IF the projectile has LEFT the barrel at the time that the muzzle COMMENCES its movement (i.e. that the movement of the muzzle will have zero impact on point of impact).
You are repeating one of the fundamental misunderstandings conserning recoil. Recoil, and hence movement of gun/muzzle, is instantanious. There is no "delay" in the effect of recoil to a gun.

Did you sleep well during the lessons in physics at shool, "K60 in Aus?"
superstring
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Re: When is recoil felt?

Post by superstring »

K60 in Aus wrote:
KJK, it says it all in the first few words..."muzzle displacement from the original position". Sounds pretty clear cut to me. The hypothesis is that the muzzle displacement is completely irrelevant for a single shot psitol in a slow fire event IF the projectile has LEFT the barrel at the time that the muzzle COMMENCES its movement (i.e. that the movement of the muzzle will have zero impact on point of impact). The rationale for the question: are muzzle brakes just an outlet for hot air (hehehe) and another way to get a few dollars out of shooters?

Over to the Einsteins....
The recoil question has been answered earlier in the thread.

But yes, there may be another reason for using a muzzle "compensator" and that is dispersing the gases as they are expelled from the barrel. Some feel the escaping gases may be able to overtake the pellet, disturbing its' flight.
jhk.

Getting interesting..

Post by jhk. »

Shooting Kiwi wrote: If the case and slide are free to move, and for as long as this is the case, (and I take the point about gas pressure on the case adding to case-to-chamber friction), because momentum is conserved
Case and slide free to move? Well, the scenario is complicated by the recoils spring(s) counteracting slide movement. The slide compressing recoil springs, and, sorry about that, recoilsprings are exerting forces to the gun. Otherwice, you consideration is interesting.
At the beginning of the recoil stroke, when springs are moderately compressed, your model may be an acceptable approximation to the real world.
Shooting Kiwi
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Post by Shooting Kiwi »

Yes, OK, nothing in the real world is as simple as simplified theory...

If we are talking about a blow-back semi-auto, still assuming the case-to-chamber friction does not hold the case for an appreciable time, the case recoil will move the slide rearwards as soon as the bullet moves forwards. Recoil spring compression will, of course, transfer force to the frame, but remember that the force rises as the spring compresses, and it's a fairly 'weak' spring. A much bigger force is transferred to the frame by the slide moving to cock the hammer. It is most interesting to manually cycle different semi-autos and compare the cocking forces and how they vary with slide position - none that I've tried seem anything like linear. They all seem to start with a high force, which then abruptly reduces. This is mainly due to the way the moment arm of the slide on the hammer changes as their positions change. My IZH is particularly 'jerky', my Hammerli 208 is much 'smoother'. Perhaps this is an area where research might bring benefit.

So, in a blow-back semi-, some recoil force may be felt on ignition, but it is the slide slamming into the frame at its rearward extent of motion that causes the biggest 'jolt' by far. The high-speed videos, previously referenced, show this to be the case in practice.

What happens with a locked-breech semi-auto (i.e. most centre-fire), I don't know - much too difficult!
Tycho
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Post by Tycho »

Good point, about the hammer. No accident that the IZH35 and the MG2 have the hammer upside down - the compressing force is pushing against the muzzle rise... And I've seen heavy mods on some guns (i.e. Pardini) in RF where the radius at the back of the slide was reshaped to get a smoother cycling. Big potential there, at least in some guns.

Case-to-chamber friction is a huge issue with the .32, not so much in .22 (but can be seen there, too). For example, early model 280s had a huge problem there. And as the .32 is much slower than the .22, that bullet is still in the barrel when the muzzle starts to climb. Easy practical test: Put a large weight on the barrel of a .32 => point of impact goes down, in some cases massively.

From what I see in spring development, designers seem to go for longer, softer springs than some years ago. I'd guess that the idea is to delay recoil transfer to the frame as long as possible, and a progressive spring would then try to brake the slide at the end.
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Fred Mannis
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Post by Fred Mannis »

Yes, the motion of the slide against the hammer can significantly affect felt recoil. In the Colt 45ACP and its clones this motion is determined by the angle at the bottom of the firing pin retainer plate. In most commercial pistols this plate is heavily radiused ~0.125"). Some custom gunsmiths replace this plate with one that has a smaller radius (~0.050") so that the plate impacts the hammer sooner and closer to its pivot point. This removes more energy sooner from the moving slide and reduces felt recoil. The recoil spring, of course, must be selected to complement this modification.
K60 in Aus

Re: When is recoil felt?

Post by K60 in Aus »

hkj wrote:
K60 in Aus wrote: The hypothesis is that the muzzle displacement is completely irrelevant for a single shot psitol in a slow fire event IF the projectile has LEFT the barrel at the time that the muzzle COMMENCES its movement (i.e. that the movement of the muzzle will have zero impact on point of impact).
You are repeating one of the fundamental misunderstandings conserning recoil. Recoil, and hence movement of gun/muzzle, is instantanious. There is no "delay" in the effect of recoil to a gun.

Did you sleep well during the lessons in physics at shool, "K60 in Aus?"
Recoil is a function of mass and velocity. At the instant of ignition i.e. instantanious (sic) there is no velocity and hence no igintion. There has been much rambling through this thread but no empirical evidence of the internal balistics and my research doesn't seem to have turned up much at all. The point of all this is "do muzzle brakes have any benefit from the point of impact perspective?"

I did not sleep well through Physics, but clearly you did in at least one subject!
JamesHu
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Post by JamesHu »

No accident that the IZH35 and the MG2 have the hammer upside down - the compressing force is pushing against the muzzle rise...
Reckon that effect would be negligible, the mass of the hammer is tiny, the direction of the force on the slide probably doesn;t matter.

How the back of the slide is profiled might be significant in terms of perceived recoil, although I think the slide hitting the slidestop and whether there is a buffer there is probably far more significant.
Tycho
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Post by Tycho »

"Direction of the force on the slide"? What diagram did you get that out of? The important factor is the torque of the hammer, which is turned against a spring. And if this was completely irrelevant, why did the russian designers go to all that trouble in the IZH 35?

Besides, what we are talking about - at least that's what I think - is recoil management while the bullet is still in the barrel - your slide stop comes quite a while after that...
khj´

Re: When is recoil felt?

Post by khj´ »

K60 in Aus wrote:
Recoil is a function of mass and velocity.
NO!!! Shame on you...:-)
Recoil is a function of mass and accelleration!!!

K60 in Aus: you have just committed on of the most fundamental misunderstandings in physics. Again.

Velocity, "K60 in Aus" is accelleration integrated with respect to time. Physics doesn´t come much easier than that.

The Newtonian laws, "K60 in Aus" are formulated in a very simple and easily understandable way. There is no excuse for misunderstanding them.

F (recoil force) = m*a at any time, "K60 in Aus".
Shooting Kiwi
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Post by Shooting Kiwi »

khj (or whatever order you are using these three letters), don't be so rude. Oh, and acceleration is spelled with one 'l'.

It all depends upon what is meant by 'recoil'. If one means recoil force, then f=m*a, as you say, but one might be considering recoil impulse or energy or momentum. Or, indeed, their derivatives or integrals. It can all get very complicated, and unless one is clear about what is meant by 'recoil', the discussion isn't worth having.

I don't think that consideration of the recoil force alone gives one a very good understanding of the perception of the phenomenon. I suspect that, from the point of view of what the shooter feels (and that's how this thread started), it is the impulse of the recoil that is significant. You presumably know that the change in momentum produced by a force is called the impulse of the force. The impulse of the recoil force is therefore a function of velocity, although it's more convenient to consider it as the product of the force and the time it is applied.

However, whether this nit-picking is worthwhile in a rapidly-changing, non-linear system is highly debatable...
2650 Plus

Post subject

Post by 2650 Plus »

Somewhat interesting discussions but..... You dont have to know any of this to shoot A TEN, so IMHO you might want to spend your time and effort In perfecting your shot sequence instead. Good Shooting Bill Horton
Shooting Kiwi
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Post by Shooting Kiwi »

That anti-intellectual stance is worthy of a recent president af a large country!
kjh

Es heisst akselleration,- auf meine sprache....

Post by kjh »

Shooting Kiwi wrote: khj Oh, and acceleration is spelled with one 'l'.
I often add an extra l in "accelleration", just for a good measure, you punk ....
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