Primers needing second strike source of cock-on-opening?
- Thread starter 4V50 Gary
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stuckinthe60s
New member
not just bad primers but dirt and foreign objects associated with war.
All I've read points to Cock on Opening being more efficient (as in requires less force) at closing on dirty ammo/dirty chambers. To be honest, I see much greater benefits in the ability for second primer strikes with just a raise and lowering of the bolt. I don't really buy that cock on closing adds so much to the force required to chamber that it would be the difference between being able to chamber a round in a dirty chamber or not with a grown adult working the bolt.
First off, there's no free lunch.
Second, while we tend to put things into very broad groups there are a lot of variations between individual designs, and that can, and does make a difference for many people.
Third, the military bolt action and the sporting rifle bolt action are different uses, with different priorities in the designs. Also military bolt actions were influenced by military "politics" and policies, where sporters are influenced by the consumer market.
A second strike capability was once thought to be an important and useful feature. SO was the magazine cut-off, and thousand yard + sights.
More than a few of the "ideal" features from the 1890s are no longer on military rifles, and haven't been for a long time.
Note that several of both cock on opening and cock on closing actions have a striker with a grippable "knob", but not all do.
Personally, I think this is more a design engineer's idea of a good thing than the user's idea. And, either the customer (Military brass) either didn't care, or also thought it would be a useful feature. I'd be willing to bet, if we were somehow able to know the numbers what they would show is that the actual in field use of second strike capability is so low as to be essentially without value.
It can also be argued that a second strike (and training troops to do so) is actually a waste of time, and potentially dangerous in combat.
There is a significant time difference in getting a second strike with a bolt action rifle than getting one with a DA pistol.
Other than on a target range, I wouldn't even consider a second strike with a bolt action rifle. The failed round would be ejected and replaced without question.
But in military arms, "traditional" features die slowly, more often than not, in previous eras. The M1 Garand and the M14 rifles have a second strike capability. You can recock the hammer without opening the actions. Its slow, its awkward and NO ONE would ever think of using it in combat, in fact, most of the users never even knew it existed. But, it can be done.
I think the biggest advantage of the cock on opening is the shorter firing pin travel and reduced lock time because of that.
it isn't speed of operating the action. The fastest to work bolt gun I know is the SMLE and its not cock on opening.
Second, while we tend to put things into very broad groups there are a lot of variations between individual designs, and that can, and does make a difference for many people.
Third, the military bolt action and the sporting rifle bolt action are different uses, with different priorities in the designs. Also military bolt actions were influenced by military "politics" and policies, where sporters are influenced by the consumer market.
A second strike capability was once thought to be an important and useful feature. SO was the magazine cut-off, and thousand yard + sights.
More than a few of the "ideal" features from the 1890s are no longer on military rifles, and haven't been for a long time.
Note that several of both cock on opening and cock on closing actions have a striker with a grippable "knob", but not all do.
Personally, I think this is more a design engineer's idea of a good thing than the user's idea. And, either the customer (Military brass) either didn't care, or also thought it would be a useful feature. I'd be willing to bet, if we were somehow able to know the numbers what they would show is that the actual in field use of second strike capability is so low as to be essentially without value.
It can also be argued that a second strike (and training troops to do so) is actually a waste of time, and potentially dangerous in combat.
There is a significant time difference in getting a second strike with a bolt action rifle than getting one with a DA pistol.
Other than on a target range, I wouldn't even consider a second strike with a bolt action rifle. The failed round would be ejected and replaced without question.
But in military arms, "traditional" features die slowly, more often than not, in previous eras. The M1 Garand and the M14 rifles have a second strike capability. You can recock the hammer without opening the actions. Its slow, its awkward and NO ONE would ever think of using it in combat, in fact, most of the users never even knew it existed. But, it can be done.
I think the biggest advantage of the cock on opening is the shorter firing pin travel and reduced lock time because of that.
it isn't speed of operating the action. The fastest to work bolt gun I know is the SMLE and its not cock on opening.
1903 is cock on open, and it has the knob. I don't care about the knob. Because of it I can't maintain cheek weld while working the action.
It was legacy from the US krag, kept by the insistence of army brass, who probably never had to first the rifle in the field at all.
-TL
Sent from my SM-N960U using Tapatalk
It was legacy from the US krag, kept by the insistence of army brass, who probably never had to first the rifle in the field at all.
-TL
Sent from my SM-N960U using Tapatalk
FrankenMauser
New member
Bad primers were definitely a thing, as were terrible quality control, in general.
If you look at modern shotguns, you'll see a lack of safety features that were standard at the turn of the century because of crap ammunition (even the "good" stuff); because those safety features are not really needed to protect the shooter from bad QC any more.
But, as touched on above, you'll note a lack of "cocking pieces" on modern bolt guns, whereas older bolt guns almost universally included them.
Case in point: The Cock-on-close "Lee-Enfield" series, all the way up to the No 5. They retained a cocking piece for second (or multi) strike capability.
I don't believe that cock-on-open was a direct result of bad primers, and have *never* seen any documentation of such in my research or that of my friends. But it could be true.
I am pretty sure that the proliferation of CoOpen actions was just people falling in love with the 1898 pattern Mauser and copying the design. It is arguably easier to work more slowly than CoClose, which is what is going to happen 99% of the time with military arms, anyway.
There are, of course, exceptions, like the Russians adopting the Gras/Chasspot/Berdan/Whatever/NightmareConglomeration in the form of the thing we know as the 1891 Mosin-Nagant 3-line rifle. It is a clock-on-open action, from well before the 1898 Mauser. But it had little impact on the world, as it was based on even-then obsolete actions.
And the aforementioned Krag being CoOpen.
As far as I am concerned, the primer issue is fuddlore and/or a myth.
Ammo, in general, sucked. It was bad. Very, very bad. Today, we do not have any reference for just how bad it was. (Except maybe Turk 8x57, Russian x39, or bulk pack .22 LR that has rattled around in the trunk of your car or bed of your truck for 3-10 years.)
CoC and CoO were just different tricks for different chicks.
If you look at modern shotguns, you'll see a lack of safety features that were standard at the turn of the century because of crap ammunition (even the "good" stuff); because those safety features are not really needed to protect the shooter from bad QC any more.
But, as touched on above, you'll note a lack of "cocking pieces" on modern bolt guns, whereas older bolt guns almost universally included them.
Case in point: The Cock-on-close "Lee-Enfield" series, all the way up to the No 5. They retained a cocking piece for second (or multi) strike capability.
I don't believe that cock-on-open was a direct result of bad primers, and have *never* seen any documentation of such in my research or that of my friends. But it could be true.
I am pretty sure that the proliferation of CoOpen actions was just people falling in love with the 1898 pattern Mauser and copying the design. It is arguably easier to work more slowly than CoClose, which is what is going to happen 99% of the time with military arms, anyway.
There are, of course, exceptions, like the Russians adopting the Gras/Chasspot/Berdan/Whatever/NightmareConglomeration in the form of the thing we know as the 1891 Mosin-Nagant 3-line rifle. It is a clock-on-open action, from well before the 1898 Mauser. But it had little impact on the world, as it was based on even-then obsolete actions.
And the aforementioned Krag being CoOpen.
As far as I am concerned, the primer issue is fuddlore and/or a myth.
Ammo, in general, sucked. It was bad. Very, very bad. Today, we do not have any reference for just how bad it was. (Except maybe Turk 8x57, Russian x39, or bulk pack .22 LR that has rattled around in the trunk of your car or bed of your truck for 3-10 years.)
CoC and CoO were just different tricks for different chicks.
CoC rifles without knob in my small collection; 7mm Spanish Mauser, arisaka 6.5/7.7mm, 6.5mm swedish Mauser.
I don't think the knob is CoC monopoly. For dry fire practice I got used to recocking CoC action short and quick. Raise the handle and pull back just enough for the sear catches the cocking piece with a click, and forward and down again.
I tend to like CoO better. With supporting hand on rear bag, CoC is more difficult to work the action.
-TL
Sent from my SM-N960U using Tapatalk
I don't think the knob is CoC monopoly. For dry fire practice I got used to recocking CoC action short and quick. Raise the handle and pull back just enough for the sear catches the cocking piece with a click, and forward and down again.
I tend to like CoO better. With supporting hand on rear bag, CoC is more difficult to work the action.
-TL
Sent from my SM-N960U using Tapatalk
Jim Watson
New member
When those bolt actions were designed, most shooting off a bag was accomplished by pulling back the hammer on a Ballard, etc.
Then we had cocking knobs.
Now we have a forward assist to cram in a round in spite of condition of ammo and chamber.
My Swede 96 cocking piece has a "tail" that sticks up, and could be used to recock the bolt, though its not easy, and I don't think you could do it with your fingers alone. I cannot think of any situation where you would want to, but it is there, and could be used, if you work at it enough.
I can see where that would be true. However, none of the cock on closing military rifles were designed with "from the bench with supporting hand on the rear bag" in mind. They were built to be used from field positions, and do pretty well at that.
I can see where that would be true. However, none of the cock on closing military rifles were designed with "from the bench with supporting hand on the rear bag" in mind. They were built to be used from field positions, and do pretty well at that.
With struggling I can recock the Swede with thumb on the knurling. I just regard it not there.
For working CoC on rear bag, I move the supporting hand fingers to grab on the butt stock while chambering and cocking. A bit interrupting but ok. Definitely quite natural with supporting hand on forearm. That's the idea. Chambering and cocking in one forward motion.
There is way to modify a mosin to CoC. I don't care about that. Mosin is another example CoO with knob.
-TL
Sent from my SM-N960U using Tapatalk
You are right. Forgot my Eddystone. CoC without knob.
-TL
Sent from my SM-N960U using Tapatalk
Concur about documentation on bad primers. I've never seen it raised before and was wondering if anyone else heard that. It could be urban legend.
I should look for a WW I era 03 manual or one for the Krag. The soldier may have been instructed to just work the bolt, eject the cartridge and try a fresh one. Combat condition doesn't give the soldier time to mess with a cartridge. Same with police when they had revolvers. Misfire you just DA to the next chamber. On the range you ceased fired, counted to 15 seconds and try it again. On the street you didn't take the risk.
FrankenMauser
New member
I'll poll my boys and see what they can come up with, but I am pretty sure that we cannot disprove or prove that primers were any influence on COC vs COO development.
I doubt you will find any documentation either way.
I seriously doubt the change from cock on closing to cock on opening in the general design of bolt actions was driven by unreliable primers and the "ease" of a second strike.
Not saying that wasn't a result of the change, but I don't think it was the driving reason for the change. They were looking to improve the RIFLE, the ease of a second strike was, I think, serendipity.
Consider this, if your car has erratic ignition because the spark plugs are not firing reliably, you don't go and redesign the engine, or even just the ignition system, you get better, more reliable spark plugs. Even if no one is making them today, once a demand is established, they will.
Always look to the cheapest and most practical solution, first.
I seriously doubt the change from cock on closing to cock on opening in the general design of bolt actions was driven by unreliable primers and the "ease" of a second strike.
Not saying that wasn't a result of the change, but I don't think it was the driving reason for the change. They were looking to improve the RIFLE, the ease of a second strike was, I think, serendipity.
Consider this, if your car has erratic ignition because the spark plugs are not firing reliably, you don't go and redesign the engine, or even just the ignition system, you get better, more reliable spark plugs. Even if no one is making them today, once a demand is established, they will.
Always look to the cheapest and most practical solution, first.
The notion that Mauser "solved" the second-strike issue by introducing cock-on-opening in the Model 98 is demonstrably false because, as has been pointed out, several other rifles such as the Mosin-Nagant, Krag, and Carcano all used cock-on-opening before the feature was introduced in Mausers.
If cock-on-opening had anything to do with poor quality ammunition, I suspect that it was to allow the use of heavier striker springs rather than for second-strike capability. When I was a teenager, my father had a No. 4 Mk. I Lee-Enfield that he was quite fond of. Unfortunately, inexpensive surplus .303 Brit ammo had begun to dry up and all he could find was poor-quality Pakistani stuff which hang-fired like a flintlock. In an attempt to cure these hangfires (spoiler: it didn't work) he installed the stiffest Wolff striker spring he could get. This not only didn't cure the hangfires but made the previously slick and fast-cycling Enfield into one which had to be cycled vigorously as if you didn't consciously shove the bolt forward and lock it fast and hard enough, the striker spring would often cause it to fly back open.
At the same time, I was trying to solve similar issues to misfires with surplus ammo with the only two rifles I owned at the time: a Mosin and a Carcano. While the extra heavy striker springs didn't solve my issues either (again, it was crappy surplus ammo), they didn't make the actions appreciably more difficult to cycle (not that Mosins and Carcanos are known for particularly smooth actions to begin with). I suspect that this is because the camming action of a cock-on-opening action is better able to overcome the tension of a heavy striker spring than the straight-forward push of a cock-on-closing.
If cock-on-opening had anything to do with poor quality ammunition, I suspect that it was to allow the use of heavier striker springs rather than for second-strike capability. When I was a teenager, my father had a No. 4 Mk. I Lee-Enfield that he was quite fond of. Unfortunately, inexpensive surplus .303 Brit ammo had begun to dry up and all he could find was poor-quality Pakistani stuff which hang-fired like a flintlock. In an attempt to cure these hangfires (spoiler: it didn't work) he installed the stiffest Wolff striker spring he could get. This not only didn't cure the hangfires but made the previously slick and fast-cycling Enfield into one which had to be cycled vigorously as if you didn't consciously shove the bolt forward and lock it fast and hard enough, the striker spring would often cause it to fly back open.
At the same time, I was trying to solve similar issues to misfires with surplus ammo with the only two rifles I owned at the time: a Mosin and a Carcano. While the extra heavy striker springs didn't solve my issues either (again, it was crappy surplus ammo), they didn't make the actions appreciably more difficult to cycle (not that Mosins and Carcanos are known for particularly smooth actions to begin with). I suspect that this is because the camming action of a cock-on-opening action is better able to overcome the tension of a heavy striker spring than the straight-forward push of a cock-on-closing.
Just a side note, if you do currently have "crappy surplus" ammo, from anywhere other than the USA, about the only thing you can salvage for components are the bullets.
You can't (and I mean really, REALLY SHOULD NOT use the powder) and the cases will be Berdan primed, and who has seen any Berdan primers in the US (let alone the right size Berdan primers) for ages??
SO, powder you shouldn't use, primers that may be the problem, and cases with no practical way to use, that leaves only the bullet worth salvaging for future use.
I think the cock on opening was done to remove most of the force required to cock the gun to a point in the operating cycle where it didn't affect cycling the bolt and feeding ammo into the chamber.
As others have pointed out, with cock on closing, if you release the forward pressure on the bolt handle before you get the action locked, it will spring open, requiring another attempt to close and cock it. In that regard the cock on opening is superior. Distance of firing pin travel and lock time are also advantages with most cock on opening designs.
I think an easier second strike was not the primary reason, but more of a "hey, look, it ALSO does this!" thing.
You can't (and I mean really, REALLY SHOULD NOT use the powder) and the cases will be Berdan primed, and who has seen any Berdan primers in the US (let alone the right size Berdan primers) for ages??
SO, powder you shouldn't use, primers that may be the problem, and cases with no practical way to use, that leaves only the bullet worth salvaging for future use.
I think the cock on opening was done to remove most of the force required to cock the gun to a point in the operating cycle where it didn't affect cycling the bolt and feeding ammo into the chamber.
As others have pointed out, with cock on closing, if you release the forward pressure on the bolt handle before you get the action locked, it will spring open, requiring another attempt to close and cock it. In that regard the cock on opening is superior. Distance of firing pin travel and lock time are also advantages with most cock on opening designs.
I think an easier second strike was not the primary reason, but more of a "hey, look, it ALSO does this!" thing.