Limpwristing II

S

Sprig

Moderator
Egads, 40 posts to the original thread and probably just a bunch of confusion.

Limpwristing is real. Limpwristing can be mathmaticaly defined using physics and calculus. I am not going to try to teach these topics here, but I think I can explain it well enough in laymans terms.

The BIGGEST issues that effects limpwristing is ammo!!! Strange how no one mentioned this in the other thread. My wife limpwrists my HiPower and with light bullets, light load, the pistol is less then reliable. If she shoots with heavier bullets and hotter loads, the pistol works flawless.

Why is this? For every action there is an equal and opposite reaction. This means that the same energy is applied to the firearm as is the bullet. In the case of the bullet, it is accelerated to high velocities because of its light weight. That same amount of energy is used to accelerate a much heavier slide, AND recoil spring. Thus, the slide moves slower.

With limpwristing, not only does the energy of the cartridge also have to move the slide and compress the spring, but it also has to accelerate the whole firearm, the wrist, and maybe even the arm if the shooter flexes at the elbow. All of this extra mass is being accelerated by the same energy, which means there may not enough energy to operate the slide properly.

There are three good ways to get a pistol to cycle properly if the owner limpwrists.
1) Develop stronger wrists!
2) Shoot a heavier bullet in a hotter load. ( a clean and lubricated weapon certainly is a must)
3) Change the recoil spring to something a little lighter.

Normally though, a well designed pistol that is clean and lubed in good working order should shoot standard weight bullets, with standard loadings, without any problems even if there is some limpwristing.

If this doesn't explain it well enough, I will have to resort to breaking out the formulas....

Sprig
 
Sprig,

Good work. Particularly this part:

"There are three good ways to get a pistol to cycle properly if the owner limpwrists.
1) Develop stronger wrists!
2) Shoot a heavier bullet in a hotter load. ( a clean and lubricated weapon certainly is a must)
3) Change the recoil spring to something a little lighter.

Normally though, a well designed pistol that is clean and lubed in good working order should shoot standard weight bullets, with standard loadings, without any problems even if there is some limpwristing."

That is all very logical from techincal point
of view, even w/o formulas...

Which means - well designed pistol will
work even if there is some limpwristling.
And to avoid effects of limpristling while shooting not really "well designed pistols", change FACTORY recoil spring to something lighter...that is called modification of original design. Obviously, original design
was not really refined if recoil spring needs
such replacement.

Conclusion - limpwristling is not a problem
for the shooter if pistol is well designed. I was talking about it all the time...

In regard to ammo - of course you're right, if you shoot blanks, there is hardly any recoil (to be used to "run" the pistol) at all...I guess nobody talked about it, 'cause
it's kind of sure thing...

Take care.
 
Oris wrote:
"Conclusion - limpwristling is not a problem
for the shooter if pistol is well designed. I was talking about it all the time..."

Well, I want to stick up for the firearm manufactures for a moment. If the pistol is designed for the military, one would suppose that the user has strong wrists. It would be also reasonable to suppose the pistol is to shoot military specification loaded cartrigdes. In this case the recoil spring may not be correct to shoot "target" ammo by a person that hasn't done a pushup in 10 years, and the weapon may fail to cycle properly. I still would consider this pistol "well designed".

However, I would agree with you in some cases. If it is a "lady" model defense pistol. This should be designed from the start to deal with a little more limpwristing, and operate with the lower energy defense ammo. (This is generaly speaking! Some brands obviously have as much or more then the average industry standard loadings.)
Yet, if this "lady" model were to be fired in the hands of a strong wristed person using someone's "hot reloads" and experience frame battering, would this mean the weapon was not "well designed"? I would say no.

However, if a clean/lubed general purpose pistol, in the hands of a moderately fit person, fireing standard weight bullets with standard cartridge loadings, fails to operate proplerly because of slight "limpwristing", then I agree that is is NOT "well designed" and you have to wonder what the factory was thinking. Keep in mind though, that this condition means the recoil spring is to tight, and this will mean that frame battering isn't occuring thus no damage to the firearm. Manufactures may go a little tighter for reasons of production tolerances and inability to determine what ammo will be used. As removing the recoil spring is part of field stripping and cleaning, changing with a spring that suits each individual wrists and ammo selection should be considered just like buying tires for whatever vehicle you drive. Either that, or go purchase some different ammo.

Is the design of the Hi-Power at fault if it fails to cycle light ammo with my wife shooting it? Yet, I can shoot the pistol with that ammo fine, and my wife can shoot the pistol when it is loaded with more "standard" energy cartrigdes. I say no.

Sprig
 
Sprig,

I would respectfully disagree in regard
to military specifications. It's not a smart
idea to consider military people to be "strong" as a design input for pistol design.
Warrior is strong until he is wounded or in
a rush to shoot from extremely uncomfortable
position - that can happen in real combat
quite easily. No time for proper grip...but
it would be nice to have pistol working anyway, right?

In regard to spring replacement - according
to ISO 9001 (system of quality control and
relative design/production stuff), any replacement of any part is a design change
and requires approval of a TEAM. It means
that if pistol is assembled with spring of
specific tension, it was decided by engineers
that this spring is what is required.
Then you discover that this spring is too stiff and pistol is a victim of limpwristling....damn, but it was APPROVED
by the pros. You replace this spring and obviously go against the pros, but you do a right thing...In accordance with ISO9001,
you just commited CORRECTIVE ACTION, or
in simple words, you improved design to
eliminate the problem.
 
I claim that the cartridge (by this I mean the specific load, bullet weight + powder charge) and gun properties (slide mass, frame mass, recoil spring stifness, and weight of ammo in the mag) are of equal importance. the load determines the forces, the gun properties determine the response to those forces.

thought experiment:
-----------------------
let's look at a high-powered, lightweight autopistol like a Glock 22 (.40 S&W, weighs about 22 oz empty). of the 22 oz, at least 18 oz are in the slide and barrel; the frame weighs very little. if we fire one "in freefall", i.e. with nothing but air touching it, the recoil force from the case base to the slide pushes rearward on the slide. the slide will accelerate rearward. the slide and frame are connected via the recoil spring. since the frame weighs only a couple of ounces, it will be pushed backward by the recoil spring almost as fast as the slide.

recall that Newton's 2nd law can be stated as "force is proportional to mass times acceleration". since the frame weighs very little, it will take very little force to accelerate it to the same acceleration rate as the slide. therefore, the recoil srping doesn't have to compress much to push on the frame hard enough to make it "keep up" with the slide. if the recoil spring hasn't compressed much, then relative to the frame, the slide hasn't "retracted" much. this is the basic formula for stoppages. obviously, there are different stoppages possible. if there's *no* relative slide/frame motion, you've got a failure-to-extract. a little more relative slide/frame motion, and you've got a failure-to-eject. a little more, a failure-to-feed.

I also suspect that there is another case; if there's *too much* slide velocity relative to the frame, the slide will *bounce* when it hits whatever mechanical stop the pistol has (in the case of Glocks, there is a step in the frame thickness that the front of the slide impacts at full retraction). depending on the severity of this bounce, I believe feed failures can occur. therefore, for a given pistol/load combo, there are upper *and* lower limits to recoil spring stiffness for reliable operation.

now lets replace the 2 oz plastic frame with a 100 pound cast iron monstrosity. for any reasonable recoil spring, the slide will do its full travel while the "monster frame" will only move a millimeter or so. in this case, no limp-wrist failures are really possible if the recoil spring is properly sized.

the upshot of all this is that the dynamic properties of the pistol need to be considered relative to the power of the cartridge. the same Glock frame that might induce limp-wrist stoppages in .40 S&W will probably have fewer or none in 9x19 or .380. this is the tradeoff with lightweight pistols chambered for serious cartridges. if you want full power and light weight, it is your responsibility to provide enough counterforce to the recoil to ensure reliable functioning.

if you want absolute reliability in a full-power pistol even in situations with a weak grip, look to a full steel frame IMHO.
 
Just as a side note to the thought of military folks being strong: I see 18 year old chubby barely 5' girls (Airmen) everyday with a Berretta M92 in their hip...they can't even get their entire hand around it!
 
Has anyone had any experience with compensators on the end of their 45 ACPs? Since I'm lousy at physics, I was wondering if there are any physics majors who shoot major (ie. 45 Super/Rowland) and minor (ACP softball) through a comped Commander or Guvt? I'm guessing that a rigid platform (locked wrist) is VERY important with one of those double recoil spring systems like Chandler Arms, Springco, etc., but not so sure about a comp.

robert (zoology...........physics is not his strong point.)

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"But now, he that hath a purse, let him take it, and likewise his scrip; and he that hath no sword, let him sell his garment, and buy one." -Jesus Christ (Luke 22:36, see John 3:15-18)
 
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