Bolt Action Cocking Question

[Bergeron]

I've been following the discussion on the new Enfield rifles with a bit of interest, and have always been curious about the cock on close/cock on open.

Way I understand it, most rifles cock when the bolt is withdrawn, and that this is preferable. A few types of actions, Enfields, notably, cock when the bolt is closed, and this is apparently not favored by most gunnies.

Why? To me, it seems that cock on close would be preferable. I've always figured on extraction being more likely to be challenging than feeding, so it would seem that cock on closing would result in a smoother and more reliable bolt stroke than a cock on open design. Also, cock on closing allows one to open the action or remove the bolt without cocking the gun, in my mind, another benefit.

An Enfield is the only bolt gun that I've ever fired, and that was about 7 years ago, for about 30 rounds worth, so I am in need for some folks with practical experience to help educate me.

Thanks!

 

[Fumbler]

It is easier to pull a bolt handle up (cocking in most modern bolt actions is done with the bolt lift, not the pull back) than it is to push it into battery, so more force to push into battery isn't a good idea.

 

[pete f]

For what ever reason, the action of prying the bolt handle away from the stock seems to me to be an easier motion as opposed to pushing down and having to force the both the cartridge into the chamber and tension the striker spring. For me this is the one deficiency that keeps my M96 swede from being my all time favorite warrifle

 

[MrMurphy]

It's not "easier" one way or the other, it's more of a personal preference. I've got over 500 rounds through Lee-Enfields and over 800 through a variety of Mausers, and I don't have a preference for cock on opening or closing.

The fact that the Lee-Enfield still holds the world speed record for most shots fired should tell you something about which is easier to do fast. The shorter bolt throw and travel also help in that respect.

 

[Dave Markowitz]

Keep in mind that the Lee-Enfield was designed as a military rifle. In that case, cock on closing is preferable, because it reduces the amount of force required to open and extract empties that may be dirty or grungy with verdigris before they were chambered.

 

[JJohnston015]

I'm with Dave. In my experience, the hardest part of the bolt motion is opening a cock-on-opening, because you've got the combined resistance of primary extraction and cocking, and because you're starting from a dead stop, and it seems that you're using weaker muscles. With cock-on-closing, you get a running start with the bolt before you hit the point where the striker spring starts compressing, and you're pushing with the chest muscles.

I've heard (no personal knowledge) that cock-on-closing designs have a slower lock time than cock-on-opening.

 

[P95Carry]

I also am with Dave - not either just because I have had a lot to do with Enfields. One thing I always found useful was, being able to close bolt on a live round, whilst keeping trigger back (fully!!) such that the rifle was then safe in two potential modes. All needed then was a pull-back on the rear cocking piece.

Another point - just me perhaps - but the inherent smoothness of Enfield bolt function, plus the almost total lack of sideways ''slop'' (thinking here of how I find Mauser bolts very laterally sloppy) make for a smooth ability to close bolt and get in to battery. Sure, extra pressure needed but a practiced flowing operation makes this easy IMO. I hate having to sometimes work real hard to open a bolt, if perhaps a case is a tad sticky to extract ... and do not want extra work added thru an opening cocking action.

 

[Vern Humphrey]

The British chose cock-on-closing for the reasons cited -- in bad conditions, it might be difficult to extract a cartridge, and they wanted to devote all the available muscle power to caming the cartridge out of the chamber.

The down side is, if your rifle is that fouled, or your ammo that cruddy, forcing the next round into the chamber is that much harder with a cock-on-closing action.

Most people find cock-on-opening preferable, and all modern sporters are made that way.

 

[Fatelvis]

I like a rifle that cocks on closing. It seems there isnt that "jerky" feel on either opening, or closing. The cocking-on-opening rifles seem to have that feeling.

 

[Fumbler]

I was going to add to the discussion, but Vern beat me to it.
If you're worried about working a gun with a dirty chamber/ammo then it's a no win situation, both cocking types will suffer in either extraction or chambering.

 

[Mike Hull]

pete f- For what ever reason, the action of prying the bolt handle away from the stock seems to me to be an easier motion as opposed to pushing down and having to force the both the cartridge into the chamber and tension the striker spring. For me this is the one deficiency that keeps my M96 swede from being my all time favorite warrifle

If you are so inclined, there are conversion kits offered that will change your Swede's to cock on opening. It won't change the appearance of the rifle at all.
They used to be quite popular years ago when more people were converting milsurps to sporters.

Brownells, Numrich, Sarco, and the like would probably carry them

 

[Man-O-War]

My personal preference is cock on opening. Just what I am used to I guess. I have used both types and do not see any real difference except in one respect. On rifles that have scopes, I sometimes find it harder to operate the bolt on rifles that cock on closing. When a scope is mounted, you have to hold your hand differently on the bolt handle and you usually don't have quite as much leverage. That is my only real complaint and it is fairly trivial.

 

[Andrew Wyatt]

having had experience with mausers and enfields, i prefer cock on closing, as I don't notice the extra resistance in the closing stroke (since I pretty much always work the bolt at full speed), and i notice the lack of resistance in the unlocking stroke.


I suspect that benchrest shooters and hunters notice the cock on closing resistance because they do most of their shooting off a bench and only have two or three things to worry about.

when i'm shooting a rifle match, there's moving involved, and i have to find targets, and keep my rifle topped up, and not fall over that rock, and...

this means i generally work the bolt like i mean it, and don't have time to notice how hard it was to close.

 

[Feanaro]

Don't ask me why but I prefer cocking on opening. Cocking on closing feels unnatural to me. And I have never noticed that I could cycle faster with a cock on closing bolt, other things being equal(they usually are not, however). I think comparing the Enfield's speed against a Mauser's and saying it's because of the cock on closing mechanism is a little skewed. The Enfield has a shorter action and bolt throw, so it's Red Delicious apples compared to Granny Smith apples.

 

[rbernie]

From a bench - it never really seemed to matter one way or another. But when in the field shooting offhand, neither system worked well for me. I've never had a cock-on-open rifle that would let me work the bolt without requiring a fair bit of force to get the locking lugs to disengage, and this counterclockwise rotation ALWAYS caused me to lose my sight picture. However, it seemed to be even worse with a cock-on-close action - the forward pushing on the bolt with my strong-side hand always caused me to have to fight that pushing with an opposite pull from my weak-side hand, with a net result that I'd lose sight picture in a big way.

And then I started shooting with a proper sling.

The sling tension across my weak side arm gives me a natural brace to offset the forward forces needed to close a cock-on-close action, and VOILA! No more loss of sight picture when working the action for a follow-up shot. Suddenly, the cock-on-close action makes a LOT more sense to me than the cock-on-open, and I find myself gravitating towards turning small-ring Mausers and Enfields into sporters just to get a cock-on-close action.....

 

[Archie]

And......

for some mechanical reason I do not understand, one can get a lighter trigger pull without tendency to slip off the sear on a 'cock on opening' type action than a 'cock on closing' rifle.

So the gunsmiths tell me....

 

[Andrew Wyatt]

i've never heard that, but i do know cock on closing rifles do have a much longer striker travel and associated locktime.


both my enfields have better triggers than all of the mausers. they're not as good as the model 70 trigger, though.

 

[Vern Humphrey]

Quote:
---------------------------------
for some mechanical reason I do not understand, one can get a lighter trigger pull without tendency to slip off the sear on a 'cock on opening' type action than a 'cock on closing' rifle.
---------------------------------

In a cock-on-opening action, the bent (the "notch" that engages the sear) is cammed back beyond the sear and held there as long as the bolt is open. Lowering the bolt handle brings the bent more or less gently into contact with the sear.

In a cock-on-closing action, the bent makes contact with the sear as the bolt goes forward, sometimes fairly violently. This means the bent and sear engagement must be substantial for safety reasons.

 

[Fumbler]

The High Road has some of the best, most informative, discussions.

 

[lbmii]

My grandfather was a WWI combat vet who was issued the M1917 which is an Americanized Enfield in 30-06.

The Enfield action is the fastest bolt action ever designed. If you know the propper way to cycle the action.

After firing, in one smooth continous movement do the following:

1. Start to twist your wrist so your palm is up.
2. Start to move the bolt up with the base of your trigger finger and catch and open the bolt with the base of your little finger and the finger next to your little finger.
3. With your palm now facing back pull the bolt back.
4. Now rotate your palm to the front catching the bolt handle with the palm of your hand by the base of your thumb.
5. Close the bolt with the base of your thumb and pull your hand back to end with your trigger finger over the trigger ready to fire again.

Practice this till you get it real smooth.

 

[Bergeron]

Interesting.

The majority of seems to prefer the cock on close. But, if I understand correctly, the cock on close has a shorter locktime, and can have a more delicate sear engagement, leading to better potential trigger pulls. Correct?

But still, those don't sound like enough reasons to have cock on open be as superior to cock on close as the number of rifles produced each way seem to indicate.

Could it be because the Mauser/1903 and action was the first popular American actions, and following designs were influenced by them?

Still curious, but a little bit better educated.

 

[Andrew Wyatt]

The majority of seems to prefer the cock on close. But, if I understand correctly, the cock on close has a shorter locktime, and can have a more delicate sear engagement, leading to better potential trigger pulls. Correct?

I think you mean cock on open.

Cock on open is a better action type than cock on close for benchrest and slow fire, because you have lower locktimes and can have better trigger pulls. As far as i can tell, most people never shoot their rifle besides off of a bench, so they rightfully prefer the cock on open.

 

[BruceB]

Gents;

I've fired tens of thousands of rounds with both Mauser-types (cock on opening) and Lee Enfields (cock on closing) of various sorts. I find both of them perfectly useable, but the Lee Enfield wins in a hands-down speed contest.

That is not my concern, which relates to the comment regarding closing the bolt UNCOCKED on a loaded chamber. In EITHER rifle type, this is extremely dangerous. The uncocked firing pin in either design rests directly on the primer, and only a very moderate blow to the cocking-piece or striker is needed to fire the rifle. Try it sometime with a primed empty case.

One little-known feature of the #4 Mk1/2 (and the earler LEs as well, I believe) is that it possesses a "half-cock" setting for the cocking piece which absolutely locks the bolt closed until the cocking piece is pulled back to full cock. THIS is a safe way to immobilize the bolt on the #4, but letting the firing pin rest on the primer is assuredly NOT safe. No comparable feature exists on a Mauser.

DO NOT close the bolt of ANY rifle and let the firing pin rest on the primer of a live round!

 

[Bergeron]

Andrew wyatt,

Yeah, you're right, sorry about that. This discussion remindes me that I really want an enfield. Those new .308's that take M14 mags look wonderful. The cut down version looks especially nice.

 

[Feanaro]

lbmii: Yes, we know the Enfield is the fastest, most reliable, most accurate rifle ever. Please, please, please stop. You're killing a Mauser fan's ego here.

Just Kidding, of course.

But we aren't talking about Enfields alone, but rather one of the mechanisms it uses. To cock on closing, or not to cock on closing? That is the question. I say that because the Enfield is already stacked against Mausers with COO designs(bolt placement, less bolt throw) it's not fair to use the Enfield as evidence of COC's superiority.