lightweight slide?

[thefish]

With the growing populartiy of small, lightweight CCW's, i'm wondering if there will be an evolution to lightweight slides made of a combination of steel and composite materials.

I found thsi article quite intresting
http://www.cylinder-slide.com/glock.shtml

Thoughts?

 

[Skribs]

It's interesting he says "lighter slide = less muzzle flip", because making any part of the gun lighter tends to increase recoil. I'm pretty sure lighter slide = faster cycling, but I wasn't aware it would reduce muzzle flip.

 

[thefish]

possibly because material has been removed from the top, lowering the center of mass of the slide?

 

[hentown]

Also, possibly a b.s.claim!!

 

[Quat]

Less flip could come from a lighter slide. Less mass hitting the end of the line and flipping the gun up when the action cycles, as well as less mass being driven back into battery.

 

[1911Tuner]

Less flip could come from a lighter slide. Less mass hitting the end of the line and flipping the gun up when the action cycles, as well as less mass being driven back into battery.

Bingo.

Most of what we recognize as recoil in an autopistol is muzzle flip, and that comes when the slide impacts the frame. What little ballistic recoil we detect...the action/reaction event from firing the cartridge...is transferred to the frame through the recoil/action spring.

And...there's a factor even less-often considered. Nay! Two!

The faster an object is moving when it encounters an outside force, the higher its rate of deceleration. Stated simply: The harder the bullet hits the target, the harder the target hits the bullet. Newton 3 is in effect everywhere.

And...The less massive an object is at a given velocity, the higher its rate of deceleration. How efficiently is the momentum conserved? An individual #6 shot loses velocity faster than a 00 Buckshot, assuming equal starting velocities.


So. The less massive slide will decelerate faster than the more massive slide with equal outside forces. Hence, the less massive slide loses more of its initial momentum on its way to the impact abutment than the more massive slide...and it doesn't hit quite as hard. That equates to reduced muzzle flip and less felt recoil.

 

[Shadow 7D]

Ok, but it that's the case, how come we don't have a huge number of feather weight slides?

 

[rcmodel]

Because slide mass figures into the equasion on timing.
A light slide will unlock sooner, and might require a change in barrel cam timing to keep the gun shut long enough for pressure to drop and allow extraction.

rc

 

[tarosean]

Ok, but it that's the case, how come we don't have a huge number of feather weight slides?

I would imagine it's because the slide takes the brunt of all the forces. It's why frames can be made from all sorts of material and still function fine.

 

[1911Tuner]

it's because the slide takes the brunt of all the forces.

And yup. The same force that kicks the bullet in the butt punches the slide in the face.

 

[45_auto]

Any of you guys ever shot a revolver? How heavy was the slide on it? Did it have any muzzle flip or recoil? Do you believe that the recoil in the revolver is due to the empty brass case impacting the frame of the revolver?

You think that putting a heavy enough spring that the slide won't hit the frame will mean that your 1911 won't recoil??? Put a heavy enough spring in it that the slide won't move will take away the majority of the recoil?? Doesn't work that way.

Lots of misunderstanding of basic physics in this thread.

In a nutshell, lighter slides (or just a lighter spring) will reduce perceived recoil (even though the slide hits the frame harder) because the cycling time is reduced. A lightened slide or spring speeds up the cycle time. Whether this improves your personnel split times will depend on the individual shooter.

A quicker cycling action will generally be perceived as having a "sharper" recoil, while the slower action will be perceived as softer.

Good article by Bob Londrigan here:

http://www.brazoscustom.com/magart/0507.htm

Aspects of perceived recoil that we need to consider are:

Muzzle flip vs. flat shooting
Soft vs. hard perceived recoil
Recoil spread out over time
Recoil spreading out over more mass
Balance point and its affect on perceived recoil

You can change the weight with a steel or plastic frame, a longer or shorter slide, a lightened slide, a tungsten guide rod, a long dust cover, a bull barrel, a large magwell with different weight material, and a steel or aluminum mainspring housing. Depending on what combination you use, you can configure a gun that weighs anywhere from 33 oz. to over 50 oz. and has a balance point anywhere from bottom heavy, to neutral, to muzzle heavy. Since there is significantly more recoil to control in a limited gun the slower, heavier setup may work better for you.

 

[1911Tuner]

Do you believe that the recoil in the revolver is due to the empty brass case impacting the frame of the revolver?

Well...That's exactly what happens. Equal/opposite force drives the case against the recoil shield, in turn driving the frame backward. In a bolt-action rifle, another name for the bolt face is the "Thrust" face. How do you think that small imperfections like toolmarks and such are imprinted into the case rims?


The reason that recoil impulse is different in a fixed-breech arm is because the impulse is transmitted immediately to the frame...and to the shooter's hand. In the autopistol, it's transferred to the slide, and the slide transfers it to the frame through a spring. By the time the frame impacts the slide, the bullet has long since left the system, and ballistically-induced recoil is over because there's no force left to drive it.

n a nutshell, lighter slides (or just a lighter spring) will reduce perceived recoil (even though the slide hits the frame harder

Nope. Assuming equal outside forces, momentum in the light slide is the same as that in a heavy slide. Momentum = Mass X Velocity. The lighter slide is moving faster, but the momentum is the same.

And, there's that part about lower mass decelerating at a faster rate when it encounters a given outside force...AND...an object moving at higher velocity will likewise decelerate at a faster rate when it encounters a given outside force. So, in truth, the low-mass slide doesn't hit quite as hard as the high mass slide, all else assumed to be equal. The difference won't be monumental, but there will be a difference.

 

[Skribs]

Because slide mass figures into the equasion on timing.
A light slide will unlock sooner, and might require a change in barrel cam timing to keep the gun shut long enough for pressure to drop and allow extraction.

While this is true, it's not a reason for manufacturers to make a light slide. Lighter is often sought for CCW purposes, and if it has less recoil, that's two benefits. The engineers could design it from the beginning with the lighter slide, which means they don't have to change anything to accomodate for the lighter slide.

 

[1911Tuner]

The engineers could design it from the beginning with the lighter slide, which means they don't have to change anything to accomodate for the lighter slide.

They already do. Look at the Colt Officer's Model in comparison to the Government Model. Slide mass is much reduced...but there just ain't no gettin' around Issac Newton, and there ain't any such thing as a free lunch. There are limits to this thing.

When you reduce slide mass, you don't just lose on one end. Mass and momentum also figure into stripping a round from the magazine, feeding it into the chamber with all resistant forces fighting to stop it...and reliably returning it to battery.

That's why the action springs in chopped pistols are typically stronger than in their larger counterparts. Momentum lost has to be made up somehow, and the only way is to increase velocity...and the only way to do that is to increase spring force to achieve faster acceleration...and then you face the problem of the slide outrunning the magazine and riding over the next round that can't get into feeding position in time to meet it.

So, we increase the magazine spring strength to speed up the rising cartridge, but then the rounds under it are forced harder against the center rail in the slide...increasing frictional resistance and possibly bringing on short-cycle problems as well as frictional resistance against the round that gets into feeding position as the slide pushes it forward.

Oh, what a tangled web we weave when first we practice to tinker with successful designs.

 

[Quat]

You think that putting a heavy enough spring that the slide won't hit the frame will mean that your 1911 won't recoil???

There is a difference between recoil and muzzle flip. Muzzle flip is the muzzle flipping up. Recoil is the gun coming backwards.

An example of the difference is the chiappa rhino, which has the barrel underneath vs a regular revolver that weighs exactly the same. With the low bore axis, the rhino is driven straight back into your hand(s). With the high bore axis, there is more tendency to flip for the regular revolver. The recoil is exactly the same, how that recoil is presented to the shooter differs.

If you take two 1911's, one with a lightweight slide and one with a normal slide, everything else identical, there is probably more felt recoil on the one with the light slide, but there is less muzzle flip.
Because of the lowered mass, the gun is affected more by the recoil. However, the slide, essentially a giant lever acting to lift the front of the gun when it reaches the end of its travel, has less mass and is less able to lift muzzle, compared to a normal slide.
More force drives the gun backward, but there is less angular downward momentum because the slide as a fulcrum is lighter. You take a little more pounding on your hands, but keeping it from flipping is easier.

If you watch Mythbusters, it is exactly like the corked bat episode. You pick up some speed with the corked bat, but there is less energy transferred to the ball because of the reduced weight.

 

[Zak Smith]

It is not uncommon for USPSA shooters to lighten slides to make the gun run "faster and flatter."

 

[1911Tuner]

You think that putting a heavy enough spring that the slide won't hit the frame will mean that your 1911 won't recoil???

Nope.

The slide recoils and moves backward, compressing the spring. You get a little impulse transfer through the spring because when the spring starts to compress, it creates a separate action/reaction system...with the spring pushing forward against the slide and backward against the frame.

The stronger the spring, the more "solid" the connection between gun and mount, and the quicker the transfer of the impulse. Hypothetically, it's possible to install a spring so strong that the slide can't move at all. At that point, the impulse transfer would be like that in a fixed-breech weapon...like a revolver.