Cock on closing bolts and big cartridges

[melanie]

Hi guys,

Stupid question time?

I notice rifles with bolts which cock on closing only seem to be .30 to .50 cal range? (maybe bigger as well but that's what I've seen).

I've never seen one on anything smaller.

Makes me think it's a stronger design so they use it for the bigger guns?

[Die Judicii]

Hi Melanie,,
Unless I've totally misconstrued what your asking, I hav'nt seen or owned one that doesn't.

Savage .22 rf cocks soon as bolt is closed down
Howa 22/250,,, yep
CZ .17 HMR ,,,, yep

Again, I'm not sure what your asking.

[North East]

Doesn't every caliber cock on closing....except for semi-autos, flintlocks?

[Bazooker]

G'day Melanie,

It's one of the big debates with actions, cock on opening vs cock on close.

Initially cock on close was used by the Mauser 96, the Lee Enfield and the Enfield M1917, P14 and others; the idea being that all of the effort applied to lifting the bolt should be applied to removing the spent cartridge, good thinking in a battlefield or dangerous game situation.

The Mauser 98 was the action that popularised cock on open, with reduced lock times being one of the advantages.

The M17/P14 Enfields were one of the strongest actions ever made and have enough length to cater for the large magnums. Being cheap and numerous, quite a number of these were used as the basis for large calibre and magnum builds. Left as standard these would naturally be cock on close; however, many were also converted to cock on opening using aftermarket conversion kits.

Hope this sheds some light.

Baz.

[brett1868]

Doesn't every caliber cock on closing....except for semi-autos, flintlocks?

Old School Lithgow 22 had a cocking lug on the rear of the bolt, close the bolt and pull the lug back to cock. Some older Mauser actions had a similar setup with a semi floating firing pin so it wasn't resting on the primer. Some actions only require a bolt to be lifted straight up then down to cock, some others were cocked during the last inch of forward travel of the bolt before locking down. This style was dangerous as it was possible for the sear to slip and discharge the round before the bolt was properly locked. Personally I like the current design with a straight up / down to cock.

[1290]

when it comes to firearms, there are very few stupid questions....

The most common c-o-c action (in Aus) is the Lee Enfield based rifle, mostly 303Brit, but there are 25, 27, 30 cal examples throughout... dont know if there are 22 cal versions in centrefire... no doubt it has been done.. it has been necked up as well but I dont know about 50cal.

Pros and cons, I like the feel of the compressing of the fire\ing pin as closed, but most have never handled or operate such a rifle, others include the older mausers, swedes, etc NOT the 98s which are cock on open.

Cock-on-open require the lifting and camming of the bolt (after discharge - ejection) to compress the firing pin and (obviously) cock the mechanism so the the stripping of another round from the mag and closing of the bolt has only the resistance of the round entering the chamber and bolt lugs engaging.

Some prefer the feel of the c-o-o, some prefer the more linear compression of the firing pin spring on closing....

Cock on closing removes the cocking resistance from the extraction of the round after lifting the bolt - so that the lifting and rearward movement of the bolt after firing only disengages the lugs, extracts and ejects the round.

I'm unaware of any current production rifles with c-o-c... maybe there are some old-schoolers out there.

c-o-c examples include the Lee Enfield family, the Pattern 14 303 / m1917 30-06, all pre98 mausrs...
c-o-o examples include m98 mausers and all current production bolt actions...

[melanie]

Hi Melanie,,
Unless I've totally misconstrued what your asking, I hav'nt seen or owned one that doesn't.

Savage .22 rf cocks soon as bolt is closed down
Howa 22/250,,, yep
CZ .17 HMR ,,,, yep

Again, I'm not sure what your asking.

Doesn't every caliber cock on closing....except for semi-autos, flintlocks?

Just to spell it out in case I've used the wrong word or description....

I thought cock on opening was the type where lifting the bolt cocked the firing pin back. It's harder to lift the bolt the fired time because you're setting the spring, but once it's cocked it opens/closes easily.

And I think it's the SMLE that the sprint isn't cocked when you open the bolt so it's easy, and the resistance comes when you push the bolt forward, that's when it cocks the spring and firing pin?

I think the other 3 guys managed to decode my nonsense

[North East]

Hi Melanie,,
Unless I've totally misconstrued what your asking, I hav'nt seen or owned one that doesn't.

Savage .22 rf cocks soon as bolt is closed down
Howa 22/250,,, yep
CZ .17 HMR ,,,, yep

Again, I'm not sure what your asking.

Doesn't every caliber cock on closing....except for semi-autos, flintlocks?

Just to spell it out in case I've used the wrong word or description....

I thought cock on opening was the type where lifting the bolt cocked the firing pin back. It's harder to lift the bolt the fired time because you're setting the spring, but once it's cocked it opens/closes easily.

And I think it's the SMLE that the sprint isn't cocked when you open the bolt so it's easy, and the resistance comes when you push the bolt forward, that's when it cocks the spring and firing pin?

I think the other 3 guys managed to decode my nonsense

It's all cool Melanie....no dramas.

[Varmtr]

G'day Melanie,

It's one of the big debates with actions, cock on opening vs cock on close.

Initially cock on close was used by the Mauser 96, the Lee Enfield and the Enfield M1917, P14 and others; the idea being that all of the effort applied to lifting the bolt should be applied to removing the spent cartridge, good thinking in a battlefield or dangerous game situation.

The Mauser 98 was the action that popularised cock on open, with reduced lock times being one of the advantages.

The M17/P14 Enfields were one of the strongest actions ever made and have enough length to cater for the large magnums. Being cheap and numerous, quite a number of these were used as the basis for large calibre and magnum builds. Left as standard these would naturally be cock on close; however, many were also converted to cock on opening using aftermarket conversion kits.

Hope this sheds some light.

Baz.

I'm currently doing a 6.5-303 Epps with a slight twist to it, on a P14 which is a c-o-c. As other have mentioned there are kits around that will convert it to c-o-o ( Dayton Triaster is one ) which does speed up the lock time as the kit will cock the firing pin back less distance than the standard c-o-c action does. There are ways to speed up lock time on a c-o-c system.
For me c-o-o or c-o-c meh not fussed you get used to there difference's. But as others have mentioned Lee Enfield's, P14 & M17's and pre Mauser 98's for what I can remember are the only ones that are c-o-c.

[hootshoot]

Just personal opinion here but I really don't like the cock-on-close actions.

Feels spongy on the close.

I like the more crisp snap of the lift bolts then no resistances on closing.

[Bark]

I don't mind it but it does feel a bit funny the first time you use one.

[Carter]

Spongy is the word for it.

Personally prefer on-lift as well.