Arisaka TY 99 Last Ditch

I just acquired this rifle (Nagoya Series 10) 2-weeks ago. It is in fairly nice condition but I cannot figure out the safety lock-out. I can easily push the cap in but it will not rotate to lock. Production was estimated to be around Feb '45. I'm thinking the 'twist-lock' feature should work -- the other possibility is that this feature was deleted from the rifle to trim one more time consuming production step.

I have pulled the bolt but cannot determine what should be providing the lock feature when the cap is rotated. Some pictures of what should be locking up would be appreciated.

Thanks -- Randy

Hello Randy,

In order for the safety to work, the rifle has to be cocked and in the fire position. Press in on the safety knob and rotate clockwise until the groove in the knob is in the 12 o'clock position and release. This works fine on all of my 10th series rifles just fine.
Are all of your bolt parts matching? The matching safety will be welded smooth with no knurling.

I can move the safety cap in/out, but it will not even rotate in the cocked/ready-to-fire position.

I'm thinking there must be an extrusion/pin that rotates over a groove or channel that locks it up, but when I pulled the bolt out I could not see anything that would accomplish this. Guess I will need to find a diagram of where this lock-up occurs.

The rear of the receiver has a machined groove which interacts with a small lug on the safety knob. To engage the safety the knob is pushed in and rotated clockwise. The small lug then follows the groove and is held by the groove and rearward spring tension from the firing pin spring. To disengage, the safety is pushed in and rotated counterclockwise.

Randy,
The reason I asked if all bolt parts are matching is a 99 safety and firing pin are different from a 38 safety/firing pin and not interchangeable.
If you haven't done so, remove the bolt and check if all parts are matching, then make sure the components are re-assembled in the correct way.

I just pulled the bolt out again and compared your pictures with what I have and all the parts look the same. Then I put the bolt back in and SHAZAM, the safety engaged! It was pretty stiff at first to rotate the cap, but after doing it a few times is loosening up.

When I first got the rifle I could barely push the safety cap in -- so I put a little Hoppe's Lube oil on things to loosen the cap. I think this safety may have suffered the same fate and now that I have got it rotating at last it will loosen in time.

Thanks for all the help -- one problem was that initially I did not know that it had to be 'cocked' to use this safety.

WHOA, I just tried locking up the safety with the rifle un-cocked and it worked -- it will lock the rifle bolt.

Randy

good news that it works for you. thats interesting that you can engage safety while uncocked. i am unable to engage safety unless the rifle is cocked. when my safety is engaged it will lock the bolt tho. never noticed that.

Wellll, that didn't last long. I was continuing to play with the safety in the uncocked position to get it functioning a bit smoother and then it stopped working at all in that position -- it just would not rotate to lock. The safety does, however, still work in the cocked position so at least I have that working for me.

I am tempted to take the bolt apart and try to figure out how the mechanism in there works to lock up both the bolt and firing pin.

Quote:

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Originally Posted by Gusdogsr

I am tempted to take the bolt apart and try to figure out how the mechanism in there works

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Exactly what I'd be doing until it worked perfectly...must be some little thing interfering.

Quote:

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Originally Posted by browningautorifle

Exactly what I'd be doing until it worked perfectly...must be some little thing interfering.

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The only thing worrying me is that people replying to my issue here are saying that the safety should only work in the cocked position, which mine now does. Why it started working for a brief period in the un-cocked position has me wondering what was going on.

I have done a lot of searching but cannot find a source to explain the workings of this safety, like why it only works in the cocked position.

The safety works by locking onto the firing, holding it back. When the safety is off, the trigger sear is holding it back.

This CAD video will give you a good idea.

How a Type 99 Arisaka works - YouTube

To see how the safety locks on, pull both from the bolt, remove the spring and you can slide it off/on/rotate and you’ll see how the firing pin mates with the safety stem.

Be careful not to pull the trigger while locking the bolt. There is a small window where the safety and firing pin will lock with the receiver and you’ll have to remove the action/bolt release in order to manually cock the firing pin with a screwdriver or similar tool to release the bolt.

I'm still not seeing anything out of the ordinary when I pulled the bolt out and rotated the end cap off -- maybe I am just not seeing what parts should be locking up when the safety cap is rotated.

My safety is still functioning when the rifle is cocked, but no longer locks when it is un-cocked. Strange thing now is that the safety cap will not rotate to the locked position when I have snap caps (dummy shells) loaded up -- is the safety feature supposed to function with the rifle cocked and loaded? I should think this would be a key use of the safety.

I really prefer to keep a snap cap loaded up so the firing pin can have something soft to strike (hard rubber 'primer') if the trigger is pulled.