Racking effort. Do I have this wrong?

[LVSteve]

I keep seeing in articles and on gun test videos people saying "striker guns are harder to rack because you have toi cock the striker as you pull the slide back." That seems wrong to me. Surely the striker spring is tensioned when the slide goes forward and the engagement surface of the striker catches the sear.

Now, in my experience striker fired pistol often have heavier recoil springs that hammer fired guns because there is no hammer mainspring to retard the slide during recoil. Therefore, the recoil spring has to be stiffer to make up the shortfall.

This leads me to another thing. If all the recoil force on the slide is transferred via just the recoil spring, that places the force low in your hand. With a hammer fired gun, there must be some recoil force transferred through the hammer spring and/or the hammer pivot that is not straight back like the recoil spring force.

Any thoughts from the physicists on here?

 

[Retiredguns]

I always figured the reason striker guns can be tough to rack is the heavy recoil spring. I made the dumb mistake of picking out a pistol for my Wife (once). She couldn't rack a Shield for her life. She found the G42 and it was much easier due to not needing as beefy a spring. Seems like that spring would be the only reason for hard racking?

 

[murphydog]

There are lots of variables with cycling a slide.

Blowback vs. locked breech, and type of mechanism
Chambering
Slide weight and total spring tension
Area of grasping grooves

To answer the OP's question, the effort with cycling a striker-fired and a SA or SA/DA gun is probably about equal if both types are decocked. The former if cocked has the striker "pre-tensioned", and obviously with the hammer back an SA gun will not take as much effort.

 

[THE PILGRIM]

Here’s the hardest pistol to Rack that I ever encountered.
9mm , open breech, with super stiff recoil springs.
Detonics Pocket 9.

 

[LVSteve]

I always figured the reason striker guns can be tough to rack is the heavy recoil spring. I made the dumb mistake of picking out a pistol for my Wife (once). She couldn't rack a Shield for her life. She found the G42 and it was much easier due to not needing as beefy a spring. Seems like that spring would be the only reason for hard racking?

That animation shows it perfectly. The striker isn't cocked until the slide is moving forward.

 

[LVSteve]

There are lots of variables with cycling a slide.

Blowback vs. locked breech, and type of mechanism
Chambering
Slide weight and total spring tension
Area of grasping grooves

To answer the OP's question, the effort with cycling a striker-fired and a SA or SA/DA gun is probably about equal if both types are decocked. The former if cocked has the striker "pre-tensioned", and obviously with the hammer back an SA gun will not take as much effort.

An SA or DA/SA gun will be easier to rack with the hammer cocked, that's easy to see. The thing with a striker fired gun is that everything is reversed. Pulling the slide back does nothing to compress the striker spring if it has been released by pulling the trigger. That spring can only compress once the striker is engaged on the sear and slide allowed to move forward to close the action.

If the gun was already cocked then the striker spring is compressed with one end of the pushing against the retainer at the back of the slide, while the other is pushing the striker, holding the engagement surface against the sear. In theory, it should help you pull the slide back, but striker springs are so short that the force goes to nothing after the slide is moved about 0.25" or maybe less.

As the striker mechanism does nothing to impede the slide under recoil, the striker fired version of a hammer gun (same caliber, obviously) must have a heavier spring to make up for the lack of mainspring. Therefore, starting both types from a hammer down/striker released condition, the initial force to move the slide is probably similar. However, the hammer cocks back pretty quickly, so now the shooter is working against just the recoil spring, which is lighter than the recoil spring in the striker gun.

As the subject has been raised, I view guns with a "pre-tensioned striker" as follows. When the slide is racked and returned to battery, the striker spring is compressed to some degree. When the trigger is pulled, the striker spring is compressed more until the sear releases the striker. The compression measured "at rest" can be expressed as a percentage of the compression observed at sear release.

 

[BC38]

That animation shows it perfectly. The striker isn't cocked until the slide is moving forward.

True - for THAT gun, but as I understand it for a lot of striker-fired guns the striker is partially cocked by cycling the action and then it gets cocked the rest of the way as you pull the trigger.
The purpose is to make the trigger pull shorter - because the striker doesn't have to go from un-cocked to full-cocked entirely by the action of the trigger. The trigger only has to move far enough to accomplish half of the cocking action
At least that's the way I've always understood it.

 

[LVSteve]

True - for THAT gun, but as I understand it for a lot of striker-fired guns the striker is partially cocked by cycling the action and then it gets cocked the rest of the way as you pull the trigger.
The purpose is to make the trigger pull shorter - because the striker doesn't have to go from un-cocked to full-cocked entirely by the action of the trigger. The trigger only has to move far enough to accomplish half of the cocking action
At least that's the way I've always understood it.

Watch the animation carefully and you will see that the sear moves back as the trigger is pulled exactly as you suggest. Typical Glock/M&P etc.

 

[BC38]

Watch the animation carefully and you will see that the sear moves back as the trigger is pulled exactly as you suggest. Typical Glock/M&P etc.

Yep, but I was of the impression some designs move the striker to half-cock before the slide goes into battery.
An example that comes to mind is the P08. Maybe that's a unique example? I dunno...

 

[LVSteve]

Yep, but I was of the impression some designs move the striker to half-cock before the slide goes into battery.
An example that comes to mind is the P08. Maybe that's a unique example? I dunno...

Well, there's no "half-cock notch" on a striker gun that I know of, but the pre-loading of the striker spring serves the same purpose. I think Glocks are 60% pre-loaded, but Caniks, Walthers and probably the VP9 use a lot more pre-load, making them almost single action.

 

[BC38]

Well, there's no "half-cock notch" on a striker gun that I know of, but the pre-loading of the striker spring serves the same purpose. I think Glocks are 60% pre-loaded, but Caniks, Walthers and probably the VP9 use a lot more pre-load, making them almost single action.

Agreed, that is why I didn't use the word "notch", just that it was half-cocked - though preloaded is actually a better more precise term.

 

[Walter Rego]

True - for THAT gun, but as I understand it for a lot of striker-fired guns the striker is partially cocked by cycling the action and then it gets cocked the rest of the way as you pull the trigger.
The purpose is to make the trigger pull shorter - because the striker doesn't have to go from un-cocked to full-cocked entirely by the action of the trigger. The trigger only has to move far enough to accomplish half of the cocking action
At least that's the way I've always understood it.

I have a Kahr K9. The striker is partially cocked by the action of the slide when the slide moves forwards after chambering the first round or during the firing cycle. And then the DAO trigger system moves the striker further back by the interaction of the trigger, trigger bar and striker until the striker reaches the maximum rearward travel, the striker safety plunger is depressed (like a firing pin safety) and then the striker releases to fire the cartridge.

The disadvantage is no second strike capability should you have a defective round. And the same can be said for a lot of semi autos these days that don't have an external hammer like a 1911. But the doctrine also says you should eject the defective round and try the next one if you are in a firefight anyway.

And by the way, this gun has a 20 lb spring as standard and it is tough to rack. I suspect it needed to be stiffly sprung in order to function properly with its short 3.5" barrel, and also since there are no restrictions on firing 9mm +P rounds which are commonly used as self defense ammo these days.

 

[chief38]

Remember, striker fired guns are usually much smaller and thinner for concealed carry. Their small size also makes them more difficult to rack not to mention that the ultra small striker fired carry guns are also smoother and less grabby so they can fit into a pocket easier. Those features don't help ease of racking either. Practice is essential to stay proficient.

 

[D Brown]

I keep seeing in articles and on gun test videos people saying "striker guns are harder to rack because you have toi cock the striker as you pull the slide back." That seems wrong to me. Surely the striker spring is tensioned when the slide goes forward and the engagement surface of the striker catches the sear.

Now, in my experience striker fired pistol often have heavier recoil springs that hammer fired guns because there is no hammer mainspring to retard the slide during recoil. Therefore, the recoil spring has to be stiffer to make up the shortfall.

This leads me to another thing. If all the recoil force on the slide is transferred via just the recoil spring, that places the force low in your hand. With a hammer fired gun, there must be some recoil force transferred through the hammer spring and/or the hammer pivot that is not straight back like the recoil spring force.

Any thoughts from the physicists on here?

Without getting too deep into it, yes there would be a force vector for the hammer spring. The inertia would be very slight since only the weight of the spring, strut, and partial weight of the hammer would provide input to that vector.

 

[LPD256]

With all the arthritis I have in my hands it has become harder to rack most small semi-autos. I frequently carry a Gen 1 Shield. I ordered the pictured device from Recover Tactical. Easy installation and easy racking. They make the device for other models as well.

 

[Oldsalt66]

Watch the animation carefully and you will see that the sear moves back as the trigger is pulled exactly as you suggest. Typical Glock/M&P etc.

Thats a diagram of how a "safe action" Glock works, not M&P.

On an M&P, the striker is actually full cocked for firing by the action of the slide returning to battery.

When the trigger is fully pressed, the M&P striker moves rearward only a a few thousandths of an inch, as an artifact of the disengagment of the sear, but unlike as with the glock wherein trigger pull provides roughly 40% of the rearward striker movement necessary to cause cartridge ignition, the tiny rearward movement of the M&P striker is entirely superfluous to the operation of the firearm.

S&W cleverly focused on that insignificant rearward motion of the striker to claim the M&P is actually a double action pistol for competition purposes.

In summation:

Practically, the striker is fully cocked by the slide returning to battery as single action pistol.


But there is, a tecnicality: the M&P is considered a double action pistol because there is a small, only a few thousandths of an inch, rearward movement of the striker as the trigger is pulled all the way.

 

[Naphtali]

Slight topic modification??

Were OP's query intended to address a shooter who has weak hands and seeks an easy cocking semiautomatic, Beretta and Taurus offer semiautomatic DA/SA pistols between 22LR and 380 ACP that can be loaded directly into tip-up barrel, no slide racking. With barrel seated pistol fires as a conventional DA/SA pistol.

Hope this contributes something useful for OP.

 

[THE PILGRIM]

I’m having problems racking my Kahr Runt 9. I like the Kahr trigger pull.
The Kahr is like shooting a Revolver Double Action.
Have dingle- dangle triggers on Glock 43x, Ruger LCP Max, Ruger LCP 22.
Looking for one more 9mm, maybe SIG 365 to evade that dangle.