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Cock on Close Vs Cock On Open

M

mikehill85

Sergeant of the Hide
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Sep 30, 2019
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Most bolt action rifles are cock on open but there are a few, particularly older rifles, that are cock on close. That got me wondering something. With my rifle (which is cock on open), I can't insert the bolt when the firing pin isn't cocked. For storage, I decock the firing pin manually to avoid wearing out the firing pin spring and noticed that if I forget to recock it I can't reinsert the bolt. It's a good thing it doesn't let you because when the firing pin spring isn't cocked the firing pin head protrudes from the bolt body.

I am mainly wondering if anyone knows the mechanism by which cock on close style bolt actions avoid having a protruding firing pin when the firing pin isn't cocked. I've read some information comparing the two systems but I didn't turn up any information about this particular subject and was just curious about it. I'm assuming they can't have a protruding firing pin.
 
No need to de-cock your bolt for storage. Springs fatigue by cycling them, not sitting under static load. So you’re probably causing fatigue, not reducing fatigue.

Ever wonder how those hundred year old military bolt actions still fire? Nobody was decocking them.
 
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mikehill85 said:
.......I am mainly wondering if anyone knows the mechanism by which cock on close style bolt actions avoid having a protruding firing pin when the firing pin isn't cocked. .....
Click to expand...

What makes you think it isn't protruding when it isn't cocked?
 
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Supersubes said:
No need to de-cock your bolt for storage. Springs fatigue by cycling them, not sitting under static load. So you’re probably causing fatigue, not reducing fatigue.

Ever wonder how those hundred year old military bolt actions still fire? Nobody was decocking them.
Click to expand...

I'm not saying you're wrong but I'm wondering what mechanism/process would cause more fatigue on a spring by leaving in a relaxed state vs leaving it fully loaded for extended periods of time. In the worst case I have simply reduced the number of times I can fire the gun by 1 round.
 
Edds said:
What makes you think it isn't protruding when it isn't cocked?
Click to expand...
I'm not saying I know for sure it doesn't protrude. I'm asking. That said, a protruding firing pin could be potentially dangerous because you could have an out of battery cartridge detonation if for instance you slammed the bolt really hard picking up a cartridge from the magazine or the cartridge snagged going into the chamber for whatever reason. Those things definitely happen and if it happened with a protruding firing pin you could have a very bad day.
 
mikehill85 said:
Well, that could be potentially dangerous because you could have a cartridge detonation if for instance you slammed the bolt really hard picking up a cartridge from the magazine or the cartridge snagged going into the chamber for whatever reason.
Click to expand...
When you close the bolt, it will cock.
 
Edds said:
When you close the bolt, it will cock.
Click to expand...
Right and before that you just have a firing pin which is protruding from the bolt face directly in contact with a cartridge's primer, that could easily detonate the cartridge if it doesn't feed properly? That doesn't make sense to me...unless the safety standards were much different back when they rifles were made. Do you know for a fact they do protrude on cock on close bolt actions? I'm looking for more than speculation.
 
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mikehill85 said:
I'm not saying you're wrong but I'm wondering what mechanism/process would cause more fatigue on a spring by leaving in a relaxed state vs leaving it fully loaded for extended periods of time. In the worst case I have simply reduced the number of times I can fire the gun by 1 round.
Click to expand...

A quick google search should sort this out. Doesn’t matter either way, this isa non-issue. What I was trying to point out is your habit is superfluous. You can stop doing it. For what it’s worth, even when you decock it, the spring is still preloaded, just very slightly less so than when fully cocked.
 
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Supersubes said:
A quick google search should sort this out. Doesn’t matter either way, this isa non-issue. What I was trying to point out is your habit is superfluous. You can stop doing it. For what it’s worth, even when you decock it, the spring is still preloaded, just very slightly less so than when fully cocked.
Click to expand...

Noted. Thanks for the advice.
 
This is so dumb.

Just hold the trigger down while you close the bolt.

Or simply dry fire it. You don’t need to take out anything to “relive spring pressure”. The firing pin will protrude when it’s no longer held back by the trigger. That’s how springs work. If you have a feed issue then it won’t be in line to hit the primer. If it can hit the primer then it will feed fine.
 
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spife7980 said:
This is so dumb.

Just hold the trigger down while you close the bolt.

Or simply dry fire it. You don’t need to take out anything to “relive spring pressure”. The firing pin will protrude when it’s no longer held back by the trigger. That’s how springs work.
Click to expand...

I don't store my rifle with the bolt in it. When you lift the bolt handle to remove the bolt it recocks and when you remove it it stays cocked...even without the trigger. Anyway, all I have to do to "dry fire it" out of the gun is rotate the back of the bolt 90 degrees. To recock it I rotate it 90 degrees in the other direction. It takes 5 seconds. That's not the point of the thread anyway.
 
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Supersubes said:
No need to de-cock your bolt for storage. Springs fatigue by cycling them, not sitting under static load. So you’re probably causing fatigue, not reducing fatigue.

Ever wonder how those hundred year old military bolt actions still fire? Nobody was decocking them.
Click to expand...

Agreed.

Regardless of cocked or not I leave the bolt open in the safe or on a stand. Anytime, I'm not in full control of the weapon.
 
Culpeper said:
Agreed.

Regardless of cocked or not I leave the bolt open in the safe or on a stand. Anytime, I'm not in full control of the weapon.
Click to expand...

Thanks. Not at all the point of the thread though.
 
Yeah. I talked about it but I never asked for any advice about it. As you've noted others have already chimed in with their unsolicited advice on the subject. I think we can give it a rest now. It takes me 5 seconds to do maybe once a year, definitely doesn't hurt anything, and may help stop the firing pin spring from weakening over time. I'll just keep on doing it if its all the same to you.
 
mikehill85 said:
Yeah. I talked about it but I never asked for any advice about it. As you've noted others have already chimed in with their unsolicited advice on the subject. I think we can give it a rest now. It takes me 5 seconds to do maybe once a year, definitely doesn't hurt anything, and may help stop the firing pin spring from weakening over time. I'll just keep on doing it if its all the same to you.
Click to expand...

Imagine you said “I can’t fit the groceries in the car because the dead hooker is taking so much space”. Then you get upset because nobody wants to help you with grocery suggestions. The most interesting thing about your post is the hooker...I mean your quirky decock habit.
 
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What do I mean? I bet you are that person that calls the library, asks for the reference desk, and then make the little old lady look it up for you. Like @spife7980 wrote, "this is so dumb".
 
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Culpeper said:
What do I mean? I bet you are that person that calls the library, asks for the reference desk, and then make the little old lady look it up for you. Like @spife7980 wrote, "this is so dumb".
Click to expand...
Oh, I see. You’re pretending to know the answer to the question I asked originally. That’s funny. I just wanted to ask a question I found interesting and I didn’t know the answer to. I don’t understand where all the anger/resentment comes from. I’m not sure why this thread had to devolve into the Great Inquisition over whether to take 2 seconds to decock your striker spring but that’s the Internet for you. “You’re an idiot because you do this thing I’m too lazy to do.” Don’t worry I won’t bother asking another question on these forums again that has an answer that is more complicated than “You’re an idiot for asking a question.”
 
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Fig said:
I think he suffers from OCD. He just didn’t tell you about touching every light switch in his house before manually decocking.
Click to expand...
Actually I think you’re the one with OCD due to your obsession over whether or not someone stores their bolt gun with a cocked striker spring or not.
 
obsession.gif
 
mikehill85 said:
For storage, I decock the firing pin manually to avoid wearing out the firing pin spring
Click to expand...

Springs don't "wear out" from remaining compressed. They fatigue from cyclical stresses, you know like the stresses from each cycle of compression and extension.

So by trying to "save" your firing pin spring you're actually shortening its useful life.
 
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308pirate said:
Springs don't "wear out" from remaining compressed. They fatigue from cyclical stresses, you know like the stresses from each cycle of compression and extension.

So by trying to "save" your firing pin spring you're actually shortening its useful life?
Click to expand...
How is storing a spring in a stressed position not going to shorten its useful life. I’ll be waiting for an answer.
 
mikehill85 said:
I'm wondering what mechanism/process would cause more fatigue on a spring by leaving in a relaxed state vs leaving it fully loaded for extended periods of time.
Click to expand...

That's not how spring works. That's now how they work at all.

In any case, your gun storage habits are beyond the stupid.
 
308pirate said:
That's not what I said. If you want to understand how springs really work become a mechanical engineer.
Click to expand...
308pirate said:
That's not how spring works. That's now how they work at all.

In any case, your gun storage habits are beyond the stupid.
Click to expand...
I am actually a mechanical engineer and creep is a real thing. A thing you obviously can’t comprehend to the point you can’t look past it to try to answer the question that was originally asked. If it takes me 5 second to decock my striker spring so I don’t have to worry about creep weakening it, I will put in that effort.
 
spife7980 said:
This is so dumb.

Just hold the trigger down while you close the bolt.

Or simply dry fire it. You don’t need to take out anything to “relive spring pressure”. The firing pin will protrude when it’s no longer held back by the trigger. That’s how springs work. If you have a feed issue then it won’t be in line to hit the primer. If it can hit the primer then it will feed fine.
Click to expand...

How else is the OP going to keep from getting framed like Bob Lee Swager if he doesn't remove the bolt and firing pin from his rifle during storage?

#firingpinspringlivesmatter
 
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As I see it- even if the firing pin is protruding as you go to chamber the round it would not hit the primer hard enough to ignite. It would just push back into the bolt face and compress the spring a tiny bit. It should need a running start. I've had a rifle that didn't freely release the firing pin- and with only that little resistance it would fail to fire.
 
mikehill85 said:
I think it means the firing pin is pulled back and cocked when you close the bolt.
Click to expand...
Do you think it means that’s the only time in the bolt cycle that the firing pin is retracted?
 
Tokay444 said:
Do you think it means that’s the only time in the bolt cycle that the firing pin is retracted?
Click to expand...
Not necessarily which was what I was originally asking. Perhaps you’re one of the chosen few who can read two paragraphs.
 
mikehill85 said:
I am mainly wondering if anyone knows the mechanism by which cock on close style bolt actions avoid having a protruding firing pin when the firing pin isn't cocked. I've read some information comparing the two systems but I didn't turn up any information about this particular subject and was just curious about it. I'm assuming they can't have a protruding firing pin.
Click to expand...

Cock on close, the striker is drawn to the rear as it collects the sear on the forward stroke, not as the bolt handle is lowered, your firing pin would not be in contact with the primer at the point where is has collected a round and is in the chamber.
If you were to depress the trigger so that the striker was not drawn to the rear when you close the bolt the firing pin will be protruding from the bolt face.
The reason why this isn't an issue is because there is no practical application with a cock on close action for closing and decocking on a live round.

This video from the 2:03 mark shows a cock on close actions function:
 
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308pirate said:
You forgot to add "in an incorrectly designed spring"
Click to expand...
Sure. In a perfect world creep doesn’t exist. Do you know whether or not your spring was properly designed? Again, I take the 5 seconds a year to not have to wonder about that.
 
I can’t think of any modern bolt action that is 100% cock on close.
Cock on close in its current sense refers to the cocking piece bumping the top sear due to poor timing, as the bolt lugs pull the bolt forward to final battery. The cocking piece has already long since done it’s job with the cam or cams on bolt open by this point, and this is unneeded extra cocking on close, unless you’re running and Ultimatum Deadline, in which case I believe they 50/50 cock on open clock on close to alleviate some of the extra force required to open a 60° bolt throw.
But you’re a mechanical engineer. You already know all this.
 
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mikehill85 said:
I think it means the firing pin is pulled back and cocked when you close the bolt.
Click to expand...

Not has much as you may think. With your line of thinking the Golden Gate should never have a load of vehicles and pedestrians on it to make it last longer.
 
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Tokay444 said:
I can’t think of any modern bolt action that is 100% cock on close.
Cock on close in its current sense refers to the cocking piece bumping the top sear due to poor timing, as the bolt lugs pull the bolt forward to final battery. The cocking piece is already long since done it’s job with the cam or cams on bolt open by this point, and this is unneeded extra cocking on close, unless you’re running and Ultimatum Deadline, in which case I believe they 50/50 cock on open clock on close to elevate some of the extra force required to open a 60° bolt throw.
But you’re a mechanical engineer. You already know all this.
Click to expand...
I wasn’t talking about cock on close in modern bolt actions.
 
Tokay444 said:
I can’t think of any modern bolt action that is 100% cock on close.
Cock on close in its current sense refers to the cocking piece bumping the top sear due to poor timing, as the bolt lugs pull the bolt forward to final battery. The cocking piece has already long since done it’s job with the cam or cams on bolt open by this point, and this is unneeded extra cocking on close, unless you’re running and Ultimatum Deadline, in which case I believe they 50/50 cock on open clock on close to alleviate some of the extra force required to open a 60° bolt throw.
But you’re a mechanical engineer. You already know all this.
Click to expand...

No, no he does not already know this. :)
 
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