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Recoil Springs
JohnT
Member Posts: 384 ✭✭✭
Before I jump into something, I have some questions.
Does anyone know the spring weight for a Tokarev TT-33 (7.62 x 25 )?
I also have 9mm and 38 super bbls, but the springs with them seem weak and I want to 'tune' the springs to my loads.
If a spring is a ' 16 pound ' spring, what does that mean ?
Does it refer to 16 pounds in compression while installed ? Or is it 16 pounds per inch compressed (Hook's Law) ? Or something different.
I want to go through some springs I have and separate them by ID and stiffness. I have a rig to measure the spring stiffness, but without knowing what the '16 pound' specification refers to, I will have much more trial and error.
Any and all feedback is much appreciated.
Does anyone know the spring weight for a Tokarev TT-33 (7.62 x 25 )?
I also have 9mm and 38 super bbls, but the springs with them seem weak and I want to 'tune' the springs to my loads.
If a spring is a ' 16 pound ' spring, what does that mean ?
Does it refer to 16 pounds in compression while installed ? Or is it 16 pounds per inch compressed (Hook's Law) ? Or something different.
I want to go through some springs I have and separate them by ID and stiffness. I have a rig to measure the spring stiffness, but without knowing what the '16 pound' specification refers to, I will have much more trial and error.
Any and all feedback is much appreciated.
Comments
sru92...Life Member NRA (EPL)
sru92@libcom.com
When asked if there was room for forgiveness in regard to the 9/11 attacks, General Schwartzkof said, "I believe that forgiving them is God's function. Our job is simply to arrange the meeting".
Why do Commanders (and other short slide variants) have heavier springs?
We've all heard that it's to reduce frame battering with the faster moving slides.
Poppycock! Balderdash! Sheep dip!
In the first place, the slide doesn't hit the frame all that hard, and the Commander slide hits with even less potentially destructive force than the 5-inch slide...even with equal spring rates.
In any impact event, mass and momentum are the factors that determine damage. i.e. If you had to knock down a brick wall, which tool would you choose for the task...a framing hammer or a 10-pound sledge?
With the Commander, you have lower mass. Because the momentum of the slide is theoretically equal to that of the bullet, the impact momentum can be no greater than the 5-inch slide...with equal springs.
But equal momentum is only equal in the absence of outside force, or in the presence of equal outside force...and those are never equal in a working pistol because there are outside forces acting on the slide that the bullet doesn't suffer.
Here's why:
An unwritten part of Newton 3 determines that the faster an object is moving when it encounters a given outside force, the more rapidly it decelerates. Likewise, the lower the mass of a given object when it encounters an outside force.
Thus, you have two factors that lower the potential for impact damage...but there's one more that's rarely considered.
Because the shorter slide means a shorter barrel, and because the slide's momentum can't be greater than the bullet's...the faster, lighter slide starts out with less momentum than the 5-inch slide, assuming equal ammunition.
Then why is the Commander typically equipped with a heavier recoil spring?
The answer is simply for reliable return to battery. The lowered mass needs higher velocity to strip, feed, and chamber a round with the same reliability as the 5-inch slide. The Commander slide has shorter travel rearward, which means that it also has a shorter runup to the magazine. The spring not only has to accelerate the slide to a velocity needed to provide it with the necessary momentum...it has a shorter distance to do it in.
Your sig line got my dog a hug and a treat. The cat looks at you with disdain.
Yes...but I've discovered that very often making a flat statement without explaining why can draw some flak. Sometimes, it does it even with a detailed explanation.
Recoil and the shooter LIMP WRIST the darn thing. "PRAISE THE HARD-BALL GUN"
EDITJohn I respect your opinion But I hope we can agree to disagree on some things I THINK I have found out in shooting and building 1911 Match Pistols. I shoot Bulls-EYE match guns These are Tuned to function on the light side of velocity. To have take advantage of lighter recoil....If you think of equal and opposite reactions you CAN NOT just look at the bullet going one way and the slide going the opposite. The BIGGEST factor is. What is locating the pistol. If one were to take a 1911 and hang it by two strings and trip the trigger remotely the bullet will fire but the pistol will not fully cycle. This was brought to light When I had my first Bulls-Eye gun built for me by my MENTOR. He was built like a tank. I am 6'1" Wear a 15-35 Shirt and 37long sport-coat.weigh 140 pounds For all practical purpose I am those two strings holding that pistol [:I] The gun was built I tried factory wadcutter loads and my handloads gun would malfunction 3 out of ever 5 shots in a string. Gun went back to mentor he tweaked the lockup sent back to me .Same problem This when on longer then I hate to admit. Finally he met me with his reloads My reloads and Factory loads.300 rounds later he had sot a box of 50 each of all three types of ammo WITHOUT one malfunction I had shot 50 with each type Never could get 5 shots with out at lease one and most times 2 or more malfunctions per string.
Root cause the frame of the pistol moved when I shot It but did not move when he shot it . the pistol has Bomar Rib/ We then tried a BALL gun this is a pistol designed to shot 230 Ball ammo with very few modifications . I shot a box of 50 HARD BALL with my pistol and he
shot 50 hard ball with his pistol My mentor was a 2600 shooter in 2700 NRA matches I beat him by 3 points in the 50 rounds of timed and rapid with Ball ammo . Thus my favorite Quote "PRAISE THE HARD-BALL GUN" Function is related to many factors a hard hold will print much lower on a target then a very light hold. ALSO a heavy slow bullet will print much higher then a light fast Bullet. You would think that slow bullet would Drop more but in fact the barrel has risen much higher because Barrel time of the slow bullet.
One at a time.
The failures are partly related to the barrel tilt angle, but it usually only becomes an issue when the frame ramp specs are right on the peg. The main problem is low slide mass and the necessarily heavy recoil spring, which makes the gun more grip sensitive...and the fact that the slide travel and runup is even shorter than in the Commander.
The recoil impulse isn't related to the bullet dwell time. With the typical burn rates of the powders used, the slide gets all the impulse it's going to get within a quarter-inch of bullet travel. With really quick numbers like Bullseye...peak pressure and impulse is probably obtained before the bullet base is clear of the case. Any extra momentum imparted to the slide from barrel dwell time is a bonus.
Felt recoil is another matter. 90% of the what we perceive as recoil is muzzle flip, and that comes from the slide impacting the frame. By the time the slide hits the frame, a 230-grain bullet at 830 fps is 20 yards downrange, and any ballistic recoil is long since over.
The rest comes from the slide compressing the spring. In very slow-motion videos...the gun doesn't move much until the slide hits the frame.
When the slide starts to move, the spring becomes a vectored force in a separate closed action/reaction system. It pushes forward on the slide and backward on the frame. Force forward is force backward. The stronger the spring, the harder it pushes in both directions.
Use a FLGR in a 5-inch gun and fire it without a spring. You'll be surprised at how soft the felt recoil is.
comments. Interesting but-I never had to set fire to my 1911A1 stocks.
I go with perry shooter-all the way. Karl is more likey to have more
experience with 1911/A1's than you.
Mods: This is a really a GD topic.
comments.
Well...mainly just passin' on some information that may be of interest to a few...or not.
quote:Mods: This is a really a GD topic.
As they wish.
In any impact event, mass and momentum are the factors that determine damage. i.e. If you had to knock down a brick wall, which tool would you choose for the task...a framing hammer or a 10-pound sledge?
Actually, destructive power (ie "damage") is generally correlated best with kinetic energy (not momentum).
Sure, if you want to KNOCK OVER a wall, you'd want a slow heavy object to do it (eg your sledgehammer, or even better, a wrecking ball). But if you want to "destroy" a wall in the literal sense (ie turn each individual brick into powder), you'd actually find it easier to accomplish with a high kinetic energy tool like your framing hammer.
quote:With the Commander, you have lower [slide] mass. Because the momentum of the slide is theoretically equal to that of the bullet, the impact momentum can be no greater than the 5-inch slide...with equal springs.
Yes momentum is conserved, but because energy is proportionate to the square of velocity, all else being equal (including momentum) kinetic energy will be actually be higher with a lighter mass slide.
In the context of slide-frame battering, I think that's probably the more relevant factor here. . .though I agree in principle that the small difference in kinetic energy in this particular case probably doesn't make any real-world difference, and that's not really the reason for the heavier slide spring in shorter guns.
quote:An unwritten part of Newton 3 determines that the faster an object is moving when it encounters a given outside force, the more rapidly it decelerates.
No, I don't think so.
Acceleration (which as you know, is defined as rate of change of velocity, and is mathematically synonymous with "deceleration") is equal to the force applied to an object divided by its mass. The velocity of said object is irrelevant.
It doesn't matter if the bowling ball is travelling at 100 mph or standing still, it will change velocity at the same rate if you apply a given force.
This, by the way, is the basis of some of the Einsteinian relativistic thought experiments. For example, if you're in a spaceship travelling in a straight line at constant speed X with no outside frame of reference, can you even tell that you're moving? (Answer. . .no, you cannot).
quote:
Because the shorter slide means a shorter barrel, and because the slide's momentum can't be greater than the bullet's...the faster, lighter slide starts out with less momentum than the 5-inch slide, assuming equal ammunition.
Again, don't think so. Momentum is conserved at all times meaning the slide group momentum should always be equal to the bullet momentum, regardless of slide weight. Lighter slide will recoil faster, yielding equal momentum at any part of the recoil curve.
But again, I agree that this has very little to do with why Commanders use heavier springs.
quote:Then why is the Commander typically equipped with a heavier recoil spring?
The answer is simply for reliable return to battery. The lowered mass needs higher velocity to strip, feed, and chamber a round with the same reliability as the 5-inch slide. The Commander slide has shorter travel rearward, which means that it also has a shorter runup to the magazine. The spring not only has to accelerate the slide to a velocity needed to provide it with the necessary momentum...it has a shorter distance to do it in.
This is the the "answer", I think.
In a nutshell, since the Commander slide is moving less overall distance and weighs less, it needs a higher "K" (ie poundage) spring to do the same job as a lower K spring compressed a greater distance.
quote:We've all heard that it's to reduce frame battering with the faster moving slides.
Poppycock! Balderdash! Sheep dip!
In the first place, the slide doesn't hit the frame all that hard, and the Commander slide hits with even less potentially destructive force than the 5-inch slide...even with equal spring rates.
You are absolutely, just full of yourelf, and not as well versed in anything of the physics like I suspected, but are well versed in BS!
That recoil spring does a couple things...adds weight to the slide, that it does not have, to retard the opening of a chamber under pressure, and slows down the slide. The slide is not all that fast?...seems to me the laws of physics would dictate, that a lighter object, under the same pressre as a heavier one, would have a greater acceleration, and velocity...common sense physics, which you seem to have a lack, there of...unless it is in front of you in black and white.
Take a look at the 10mm for example, in a 1911 chassis. You don't suppose that the cracked and broken frames in the first Delta Elites, were because the slide did not have enough velocity? Hrmmm..
I am thinking you need to put your books down.
Best
JohnT,
quote:We've all heard that it's to reduce frame battering with the faster moving slides.
Poppycock! Balderdash! Sheep dip!
In the first place, the slide doesn't hit the frame all that hard, and the Commander slide hits with even less potentially destructive force than the 5-inch slide...even with equal spring rates.
You are absolutely, just full of yourelf, and not as well versed in anything of the physics like I suspected, but are well versed in BS!
That recoil spring does a couple things...adds weight to the slide, that it does not have, to retard the opening of a chamber under pressure, and slows down the slide. The slide is not all that fast?...seems to me the laws of physics would dictate, that a lighter object, under the same pressre as a heavier one, would have a greater acceleration, and velocity...common sense physics, which you seem to have a lack, there of...unless it is in front of you in black and white.
Take a look at the 10mm for example, in a 1911 chassis. You don't suppose that the cracked and broken frames in the first Delta Elites, were because the slide did not have enough velocity? Hrmmm..
I am thinking you need to put your books down.
Best
Well put [^] Couldn't have said it better myself [}:)]
Just look at the lightweight commander frames that crack also [:0]
Then tell us that KNOW 1911,s that the slide doesn't hit the damn frame [B)][^]
I know they crack. They all crack sooner or later. That's the normal result of sharp corners and thin cross-sections. Engineers and machinists know them as stress points. They create stress risers, and those are the places that give rise to cracks. Those cracks are self-limiting and don't affect the function of the guns in any way.
Incidentally, those cracks can be stalled for a long time by seeing to it that there's a minimum of .007 inch of clearance between the end of the spring tunnel and the bottoms of the slide rails. I normally cut a one degree angled rake from the back end.
Moving on...
I have a pair of early 1991A1 Colts that I bought strictly for beater duty. Collectively, they're approaching 400,000 rounds about evenly split. They've both been rebuilt, and they're each on their 3rd barrels. They both cracked at roughly the 50,000 round mark. The cracks haven't traveled, nor have they caused a problem. Those cracks are a non-issue.
I've owned a half-dozen Colt LW Commanders that also cracked at those points fairly early on. I went on to shoot them until the frame rails were worn completely out. The cracks didn't travel and they never affected the pistols' function.
You swallow a camel and gag on a gnat. So much concern over the frame, when it's the slide that catches the hell. The slide and barrel assembly is the gun. The frame is basically no more than the gun mount. Cracking a frame at the junction of the impact abutment, rails, and spring tunnel isn't a concern. Cracking a slide in the port adjacent to the breechface guide blocks is a game-ender.
If you can keep the slide from moving with one thumb during the point of peak force and acceleration...really...how hard can it hit the frame after the force is removed and after compressing the spring?
Think about it.
I've seen this demonstrated with a .45 caliber Glock, too.
I've gripped the cocking serrations on a 1911 firing GI hardball ammo...and stopped all slide movement. It's not hard to do.
Since I don't feel that you believe yet, here's an interesting video for your consideration.
If you can keep the slide from moving with one thumb during the point of peak force and acceleration...really...how hard can it hit the frame after the force is removed and after compressing the spring?
Think about it.
I've seen this demonstrated with a .45 caliber Glock, too.
I've gripped the cocking serrations on a 1911 firing GI hardball ammo...and stopped all slide movement. It's not hard to do.
You are keeping it from starting and unlocking by holding it with your thumb, finger, or what ever. Hold your damn thumb about 1/32" off the back of the slide and watch what happens. It will show you the physics laws of momentumn, where in as an object in motion, will stay in motion. Once again, you are not the first bright one, to spin this wheel.
Best
EDIT
Whats more, I know the 1911 has several different uses, but it WAS NOT DESIGNED to be a LEATHERMAN. It was designed to shoot IDIOTS at close range when needed.
If you can keep the slide from moving with one thumb during the point of peak force and acceleration...really...how hard can it hit the frame after the force is removed and after compressing the spring?
Think about it.
I have thought about it, and what you're saying makes no sense at all.
Lets say I'm standing on top of a tall building holding a bowling ball over your head. See how easily I can hold it with one hand?
Now I drop it on your head. Think you can catch it after its fallen ten stories?
Why should it be hard to catch it if I could easily hold it up with one hand?
In the case of a 1911, the slide doesn't pick up momentum or kinetic energy until it starts moving. If you PREVENT it from moving with your thumb, said kinetic energy/momentum just gets transferred into your whole arm (which, not incidentally, weighs a lot more than the whole gun, and is soft).
That doesnt' mean that AFTER the slide has accelerated to full speed that smacking into the frame can't/won't cause damage.
Since I don't feel that you believe yet, here's an interesting video for your consideration.
If you can keep the slide from moving with one thumb during the point of peak force and acceleration...really...how hard can it hit the frame after the force is removed and after compressing the spring?
Think about it.
I've seen this demonstrated with a .45 caliber Glock, too.
I've gripped the cocking serrations on a 1911 firing GI hardball ammo...and stopped all slide movement. It's not hard to do.
You are as all you are doing is not letting the barrel unlock from the slide [:0] This can be done with any semi auto pistol than locks with the slide [;)] Try it with a blowback of any caliber [^]
In the case of a 1911, the slide doesn't pick up momentum or kinetic energy until it starts moving.
Momentum is equal on both ends of the system, and the momentum is never greater than at the point of peak force and acceleration. Once that's passed, it can only decelerate and lose momentum.
Read that again.
The slide can't gain speed or momentum after the accelerating force has been removed.
quote:Why should it be hard to catch it if I could easily hold it up with one hand?
That's not even a close analogy.
quote:Acceleration (which as you know, is defined as rate of change of velocity, and is mathematically synonymous with "deceleration") is equal to the force applied to an object divided by its mass. The velocity of said object is irrelevant.
Go to any reloading manual and look at the long range tables. Starting a 150-grain .30 caliber bullet at 3000 fps, and another identical bullet at 2500 fps. Calculate the percentage of loss in velocity at given ranges. The faster bullet loses a greater percentage at a given range. Newton 3 works in both directions. i.e. The harder the bullet hits the target, the harder the target hits the bullet. The faster object decelerates at a faster rate when it encounters a given outside force.
Likewise, the less massive the moving object, the faster it decelerates when it encounters a given outside force.
quote:Actually, destructive power (ie "damage") is generally correlated best with kinetic energy (not momentum).
Again...if you want to knock down a brick wall, which do you choose for the task? Speed and energy with the framing hammer...or mass and momentum with the sledge?
Mass and momentum are the properties that keep an object moving...trying to plow through on impact. Since the assumed area for frame damage is the impact abutments, mass and momentum would do the damage...not kinetic energy.
Compare the .22-250 firing a 55-grain bullet at 3600 fps with the old, original .45-70 black powder cartridge with its 405 grain slug at about 1300 fps. The 250 carries more kinetic energy at the muzzle, but which would you want to be holding if a 1200-pound Alaskan Brown charges you at 30 feet? Mass and momentum, or speed and energy?
And, on the back end...Which rifle butt would you be more willing to place against your chin and pull the trigger? The 8-pound .223 sporter...or the 8.5 pound Sharps cavalry carbine? Again...mass and momentum or speed and energy?
I ran these points by a bright young lad with a fresh 4-year degree in mechanical engineering under his belt not long ago. He was in complete agreement. To wit; The faster, lighter slide decelerates at a faster rate...mass and momentum carry the greater potential for damage in an impact event...and the slide doesn't hit the frame that hard.
He also calculated the kinetic energies for the two slides, using only their mass/weight and excluding all outside forces and assuming equal ammunition. I don't remember the exact figures, but essentially, there wasn't enough difference to flip a coin over. You'd see nearly as much difference from the extreme spread in velocities in a typical lot of ball ammunition. (GI ball is advertised at 830 +/-25 fps)
Of course, because its subject to greater force.
Same as your hand is subject to greater force if you hang it out the window at 60 mph vs 30 mph.
quote:Newton 3 works in both directions. i.e. The harder the bullet hits the target, the harder the target hits the bullet. The faster object decelerates at a faster rate when it encounters a given outside force.
Sorry, but this is silly talk.
If you want to cite physical law, at least cite the correct one. In this case, Newton's SECOND (not third) law governs acceleration, to wit:
F = MA.
Remember that one? Apparently not.
Acceleration (deceleration) is purely a factor of force and mass.
Object velocity *isn't a factor AT ALL*.
It's leading up to something. If you think this one's gone rodeo, you really don't wanna miss the last one in the series. [:D]
I'll put it up in GD
Meanwhile...back to that old bear that just busted cover at 30 feet...head down and extremely irate.
Your best chance of surviving is to inflict the maximum damage. Which do you think will give you the best chance...speed and energy...or mass and momentum?
quote:Go to any reloading manual and look at the long range tables. Starting a 150-grain .30 caliber bullet at 3000 fps, and another identical bullet at 2500 fps. Calculate the percentage of loss in velocity at given ranges. The faster bullet loses a greater percentage at a given range.
Of course, because its subject to greater force.
Same as your hand is subject to greater force if you hang it out the window at 60 mph vs 30 mph.
quote:Newton 3 works in both directions. i.e. The harder the bullet hits the target, the harder the target hits the bullet. The faster object decelerates at a faster rate when it encounters a given outside force.
Sorry, but this is silly talk.
If you want to cite physical law, at least cite the correct one. In this case, Newton's SECOND (not third) law governs acceleration, to wit:
F = MA.
Remember that one? Apparently not.
Acceleration (deceleration) is purely a factor of force and mass.
Object velocity *isn't a factor AT ALL*.
JT's example is exactly what Newton's 3rd law of motion describes: Equal and Opposite forces from two bodies.
F2 = -F1
Edit: Object velocity is indeed a factor for Kinetic energy calculations (K = 1/2mv^2)
Edit2:
quote:Originally posted by JohnT
quote:Fascinating information/conversation/discussion
It's leading up to something. If you think this one's gone rodeo, you really don't wanna miss the last one in the series. [:D]
I'll put it up in GD
Meanwhile...back to that old bear that just busted cover at 30 feet...head down and extremely irate.
Your best chance of surviving is to inflict the maximum damage. Which do you think will give you the best chance...speed and energy...or mass and momentum?
Isn't that why BIG SLOW solids are use to hunt dangerous game? I'd go w/ a 45-70 for bear up close and personal.
JT's example is exactly what Newton's 3rd law of motion describes: Equal and Opposite forces from two bodies.
F2 = -F1
Edit: Object velocity is indeed a factor for Kinetic energy calculations (K = 1/2mv^2)
What on earth are you babbling on about? You've completely missed my point.
One more time. . .
JT Einstein claims that an equal force will alter the velocity of a fast-moving object more than a slow-moving one. Here is what he claims:
quote:An unwritten part of Newton 3 determines that the faster an object is moving when it encounters a given outside force, the more rapidly it decelerates.
This is just plain wrong, and it contradicts basic high-school level mechanics.
The equation governing acceleration is F = MA, Newton's Second law.
Acceleration equals force/mass, period.
It makes no difference if an object is at rest, travelling at 100 mph, or travelling at 100 times the speed of sound. In all three cases, a given force will alter its velocity equally.
Meanwhile...back to that old bear that just busted cover at 30 feet...head down and extremely irate.
Your best chance of surviving is to inflict the maximum damage. Which do you think will give you the best chance...speed and energy...or mass and momentum?
Its a false premise.
If you're being attacked the goal is to rapidly incapacitate the attacker.
The fastest way to do that is to disrupt a vital system, either the respiratory, circulatory, or ideally central nervous system, though the latter is a small and generally highly armored target. "Max damage" is nice if you can get its. . .but its not actually the goal. The goal is TARGETED damage that disrupts a vital system.
Since both momentum and kinetic energy are products of the same factors (mass and velocity) they're not mutually exclusive. Projectiles high in one are usually high in the other.
To answer the question in a more rational way, given two bullets with the same momentum, all else being equal, you'd want the one with higher kinetic energy. Given two bullets with the same kinetic energy, you'd want the one with higher momentum.
In either case, there are practical limits in play, such as weapon weight, recoil, and expense. So even though bigger may be "better" it may not really be available.
Vf = Vo + at
Vf^2 = Vo^2 + 2aX
and
X = Vot + 1/2 at^2
Where a = acceleration, X = displacement, and t = time.
F = ma in not the only means of of determining acceleration, although is is handy for calculating moments.
Acceleration (both + & -)is simply a change of velocity over a change in time (delta v / delta t).
If F = ma was the only formula used, one could prove that a bullet drops to the ground the instant there is no force applied to it.
F = 0 thus ma = 0.
Kinetic energy is the proper "force" in this case. (k = 1/2mv^2)
quote:Originally posted by beantownshootah
quote:Originally posted by iceracerx
JT's example is exactly what Newton's 3rd law of motion describes: Equal and Opposite forces from two bodies.
F2 = -F1
Edit: Object velocity is indeed a factor for Kinetic energy calculations (K = 1/2mv^2)
What on earth are you babbling on about? You've completely missed my point.
One more time. . .
JT Einstein claims that an equal force will alter the velocity of a fast-moving object more than a slow-moving one. Here is what he claims:
quote:An unwritten part of Newton 3 determines that the faster an object is moving when it encounters a given outside force, the more rapidly it decelerates.
This is just plain wrong, and it contradicts basic high-school level mechanics.
The equation governing acceleration is F = MA, Newton's Second law.
Acceleration equals force/mass, period.
It makes no difference if an object is at rest, travelling at 100 mph, or travelling at 100 times the speed of sound. In all three cases, a given force will alter its velocity equally.