Interesting Arisaka Problem

[Tallship]

So I took the Type 38 out to the range today to shoot it for the first time. Loaded five rounds of new Hornady 6.5 jap ammo into it and closed the bolt. Everything seemed to space fine, so I pulled the trigger, and it went bang. Worked the bolt again, closed the bolt, pulled the trigger and bang. That's when things got interesting. Opened the bolt again, closed it, and bang! without ever touching the trigger. Tried it once more and the same result. Opened the bolt, dropped out the last round. Closed the bolt on an empty chamber, and the pin was still cocked, so I pulled the trigger and the pin went forward. Can't figure out what is going on. Anyone else have this experience?

[NaughtyMonkey]

As soon as you close the bolt it went bang?

Did you still hit the target?

[littlejake]

It would help to know if the striker was still cocked on the rounds that fired on bolt closure... I'm betting it was not.

I'm not an Arisaka expert; but have handled one before.

The striker sear surface must be slipping off the trigger sear surface... Possible loss of negative angle of sear surfaces (the slight angle that tends to hold the engagement of the sear surfaces.)

Possible sloppy bolt in the bolt bore that allows the striker line to change when a round is being chamber. Same thing, only slop in the bolt's bore for the striker.

Any chance you have a type 99 bolt in a type 38 rifle. I understand the type 99 will appear to work, but the locking lugs at not located for the correct head space.

There's a fellow on the forum who is very familiar with Arisaka's... I cannot recall his handle.

[Spiggy]

Check your sear, it could be gummed up.

I had this issue (thank god) while I was reenacting. Blanks don't have a chance to blow your face off

[Interloper]

Cock the rifle (empty!) and thump the butt on the ground a few times. See if the sear releases.

[Spiggy]

^this. The springs in the trigger mechanism were not working correctly, causing the sear to lightly engage the firing pin. When the bolt was wobbled or the gun was hit, it caused the rifle to discharge.

It was because of unwanted dirt and cosmoline lodged in the trigger mechanism. Everything worked fine when it was cleaned out.

[knucklehead0202]

definitely start by pulling it down and cleaning it thoroughly. arisaka bolts are stupid simple to disassemble. there may be cosmoline in the firing pin area, or, like the others said in the trigger group. clean everything up and oil it lightly then see what she does. i have a type 38 carbine and a type 99 and haven't had any trouble yet, but we can't all be lucky. if you decide you just can't stand it anymore i could sure use some 6.5x50 ammo, lol. seriously though, try it out and see what happens, arisakas are fun rifles and 100% on wtf is that factor? always entertaining to take them out. good luck and let us know how it goes.

[Tallship]

Thanks, Interloper, that's exactly what happens, and you don't even have to tap it on the floor that hard. I'm going to take apart the trigger mechanism, which seems to working pretty well and see what's going on. Anyone have some specs on the sear, so I can see if it's worn down too much? Thanks.

[littlejake]

Remove and disassemble the bolt too. The bolt take down begins by rotating that big safety knob clockwise until it comes off. The take down is intuitive from there.

Instructions:

http://www.surplusrifle.com/arisakatype38/boltdisassembly/pdf/arisakatype38bolt.pdf

[Tallship]

OK, here's what's happening. With the barrel out of the rifle, the sear is in the correct position. But when I put the barrel into the rifle, the cutout on the back of the magazine is pushing up on the trigger rocker arm, causing the sear to come down. You can actually see the sear lower as you put the final turn on the back barrel screw. Any suggestions?

[Spiggy]

hold on, let me take my arisaka apart and see if I can replicate your problem

ok, do you have a magazine housing?

the steel insert that goes into the magazine inlet

-dumb question, yes you do...

Is the magazine housing fitted to the trigger guard? or is it just floating around in there?

[Tallship]

Spiggy- the magazine housing is definitely a separate piece from the trigger guard, as they're both numbered. But after 70+ years, it's pretty well welded in there- I tried everything up to the 12 ton press. So I just ground down the front of the pivot arm, and now it clears the mag well and the sear comes up to where it should be. The gun is ready to go!

[knucklehead0202]

excellent!

[Interloper]

Sounds like you got it. Good job!