Thread: half open bolt

Hi, I've just gone for my 10 yearly firearms licence renewal.

I see, on page 17 of the Arms Code 2011, it recommends the half open bolt for rifles (action for shotguns).

For semiautomatics it is deemed safe enough to use a rigorously pretested safety catch.

The half open bolt is, to me, a special feature of the Lee Enfield action. It is reasonably safe because it cocks on closing, so some force is needed to push the bolt forward and get the cartridge into the chamber, then a second force at right angles to close the bolt. In a stumble, an oblique pressure could conceivably close the bolt but in practice it is rare. I think the Mauser 96 might be another cock on closing action ?

For every other bolt action, the firing spring is compressed and it is cocked as you open the bolt. There is no natural position where the cartridge is half way into the chamber and where a substantial push is needed to load it. One has to have the bolt handle forward and up so that a simple single direction knock can flick it closed and fully cocked. Various detents and stop devices exist or are added a modifications, but I don't know of any that are as secure as the half open bolt on the .303. I have never felt safe carrying any other bolt action with a half open bolt. I would be interested to see photos, if anyone has devised a mechanical solution to this.

I hope my new permit is in the mail, because I would like to share that I use the safety catch on my new bolt action rifle.

I test it each time I apply it: first that the bolt is locked as it should be, then by pulling the trigger hard with the gun pointed in a safe direction. When I return to a track or grovel through thick stuff where I sling it across my back, I unload, then release the safety and carry the rifle with an empty chamber (checked visually and by feel, uncocked by closing the bolt while pulling the trigger). On major tramping tracks and at the hut or camp I take out the detachable box magazine as well. I don't think this is any more dangerous than using the same procedure with a semiautomatic, which is apparently acceptable for them.

I would like to suggest that the police remove the reference to the half open bolt, now of limited applicability to a small subset of firearms in NZ, and recommend the use of the "pretested safety catch" in appropriate safe situations for all types of forearms.

I use half open bolt(on a modern firearm), much better than half cock which as you know is full cock on modern actions.
highly unlikely to close action and pull trigger in a fall(less so than a thumb or stick pushing a safety off)

Originally Posted by Bagheera

I would like to suggest that the police remove the reference to the half open bolt, now of limited applicability to a small subset of firearms in NZ, and recommend the use of the "pretested safety catch" in appropriate safe situations for all types of forearms.

+100

Here are a couple of good video clips Robbie did on tikka half cocks.

Tikka T3 half bolt safety - YouTube

Tikka T3 rifle Half Cock conversion demo bolt handle drop - YouTube

Thanks Outdoorlad, I was hoping for some visual like that.

This video illustrates a mod where the bolt handle can be flicked lightly in just one direction and the rifle is then fully loaded. The Lee Enfield half open bolt requires some force to compress the firing spring then a second force at 90 degrees.

It also looks as if it is cocked while in the "half bolt" position (not "half cocked") and I'm not reassured that pulling the trigger makes the bolt close and the primer is indented. Surely the safety catch that comes fitted on the rifle would be safer and quieter ?

I have said it before a number of times but here i go again.
A half open bolt is not half cock and is not half closed! Its half Fuckin open! Ie you can see the shell.

Half cock is a condition usable on old 303s where it is actually HALF COCKED not half open not half closed but fully closed and half cocked.

Half closed as it should be called as in the vids above may not fire in some rifles but why would you take the risk? Why not half open, you still have to work the bolt either way.
I see no problem with a half OPEN bolt or pre tested safety. Each to there own. I have issues with a half closed bolt or half cock as it is commonly called incorrectly, being taught as a safe way to carry. It is not Safe with all rifles and should not be taught as a safe carry.

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A mate of mine ties a rubber band around the scope mount, then back around the bolt handel. This allows the bolt to stay forward with bullet up the spout, but not cocked. The rubber band doesn't affect the closing of the bolt/cycling of the action etc...


In stalk mode




then ready to shoot mode

I personally just carry it cocked on an empty chamber until I get amonst the sign, then I load it with one up the spout (but not with bolt on half cock) and hold the bolt forward in the crock of my arm to stop the bolt from falling backwards and ejecting the round (VC's way) i.e. not on half cock, but with one up the spout and the bolt handle fully up. When the sign is red-hot (roaring stag coming in, or I see a deer etc..) I will close the bolt handle and put on the safety with muzzle pointed at the ground about 1.5m in front of my feet, once the target has been identified beyond all doubt I'll raise the rifle ready to shoot with finger off the trigger until I get a clear view.

kj

Just use your safety. "But it's a mechanical thing and THEY CAN FAIL"

Well so are the brakes on your car, except they're actually more likely to fail than a safety on a rifle(except on a Remington 700 or badly modified rifle). It's not a wear part generally.

Originally Posted by gimp

Just use your safety. "But it's a mechanical thing and THEY CAN FAIL"

Well so are the brakes on your car, except they're actually more likely to fail than a safety on a rifle(except on a Remington 700 or badly modified rifle). It's not a wear part generally.

Agreed, and I do use the safety with absolute confidence in it not failing...but I don't personally like to bush-bash with a loaded rifle as the safety can be flicked off in the real thick stuff. I use the safety when I'm in close and about to take the shot.

But hey, each to their own, I'd rather use a safety than a bull shit half-cock.

kj

I can feel exactly where my bolt is without lookin down to check.
I can't with my safety.
I have no problem with using the pre tested safety, just find it easy and natural to have an open bolt in the bush.


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Originally Posted by Bagheera

I would like to suggest that the police remove the reference to the half open bolt, now of limited applicability to a small subset of firearms in NZ, and recommend the use of the "pretested safety catch" in appropriate safe situations for all types of forearms.

I concur.