Jap 99 action screw

[ebb]

Pulled apart one of my junkers, that I drug home to be fixed at a later date. It has a broken off front action screw. I can find screws, but i am concerned that the threads are damaged in the receiver. I have looked online but failed to find out what the thread size is. does anyone here have this info or can point me to where i can find the size to buy a tap? Any and all help would be appreciated.

 

[Sniperhandle]

It has oddball thread pitches that are no longer used.

Japanese screw thread pitch question

Just wondering if the screw pitch/threads per inch, etc is standarized to today's specs? I'm assuming they are metric. Are there any oddball ones on any of the rifles? I currently only have T-38 and T-99 rifles, but this question is for all types of Japanese weapons. Mainly for cleaning up...

www.gunboards.com

Type 99 most common screws :
a) short front band 2 ea. 5.5x0.50x14 mm ( 5.5 diameter, 0.50 thread pitch, 14 length ).
b) long front band 1 ea. 5x0.50x28 mm.
c) long lower band 1 ea. 6x 0.75x42 mm.
d) forward trigger guard 1 ea. 6x0.75x22 mm.
e) middle trigger guard 1 ea. 6x 0.75x32 mm.
f) rear tang screw 1 ea. 6x0.75x57 mm.
T-38 most common screws :
a) forward trigger guard 1 ea. 6x0.90x21 mm.
b) middle trigger guard 1 ea. 6x0.90x32 mm.
c) rear tang screw 1 ea. 5.5x0.90x48 mm.

 

[shortgrass]

7.7mm Jap is 6 x .75mm. I think the Type 38 6.5mm is 6 x .9mm

 

[ebb]

We looked at thread gages and the only 2 that were even close was a 6. x1. but it would not start in the hole. The screws from another rifle that is also a type 99 would go in a 1/4 X28 but were a little too wobbly to suit me. Any idea where to find a 6 x .75 tap

 

[Sniperhandle]

We looked at thread gages and the only 2 that were even close was a 6. x1. but it would not start in the hole. The screws from another rifle that is also a type 99 would go in a 1/4 X28 but were a little too wobbly to suit me. Any idea where to find a 6 x .75 tap

Is this it?

M6 X .75 HIGH SPEED STEEL 4 FLUTE TAPER TAP | eBay

Quality Import.

www.ebay.com

 

[ebb]

Yes . Thank you and Short Grass both!!!! I found a standard tap and a bottoming tap as a pair on Amazon that will be here on Monday. Ive been watching Mark Novak and I don't think I ma going to go crazy on this one like he does. It has 0% finish on the metal, the stock looks like it was drug home behind a Sherman tank all the way from Japan. I steamed a lot of dents out but it still has more , i will try again. The stock is a very white colored soft wood but it has a mahogany hand guard. The stock was split from the tip to about 8 inches in front on the front action screw, and I have glued it back the handguard is split in two places and yet to be fixed. After I scraped the stock finish off I noticed a bunch of black marks that look like someone was trying make the stock spotted, Lacquer thinner would not remove the black marks so i am going to try a few with some wood bleach I have in the shop to see if they will clean up. Would you try to go back with the varnish looking finish the stock had from new or just use BLO with some stain to darken it up???

 

[SBS]

M6 x .75 is also the action screw size for the 54 Anschutz action.

 

[Dimner]

Yes . Thank you and Short Grass both!!!! I found a standard tap and a bottoming tap as a pair on Amazon that will be here on Monday. Ive been watching Mark Novak and I don't think I ma going to go crazy on this one like he does. It has 0% finish on the metal, the stock looks like it was drug home behind a Sherman tank all the way from Japan. I steamed a lot of dents out but it still has more , i will try again. The stock is a very white colored soft wood but it has a mahogany hand guard. The stock was split from the tip to about 8 inches in front on the front action screw, and I have glued it back the handguard is split in two places and yet to be fixed. After I scraped the stock finish off I noticed a bunch of black marks that look like someone was trying make the stock spotted, Lacquer thinner would not remove the black marks so i am going to try a few with some wood bleach I have in the shop to see if they will clean up. Would you try to go back with the varnish looking finish the stock had from new or just use BLO with some stain to darken it up???

Personally I'd buy a cheap mil surp stock off ebay if the one you have has no sentimental value. Sounds like yours is a train wreck.

I love my T99. All kinds of beat up. But shoots moa at 100 yards with the scout scope I mounted. But for hunting season that gets removed and I use a receiver sight. I use it in the thick brush woods. Lite and handy.

I plan to strip my stock and redo it with tung oil. My stock was duffle cut, so I have removed the top hanguard and the front bottom handguard. Just need to make some sort of cap for the front end of the stock.

 

[Dimner]

Also, those black marks might be burns? There was a thing people used to do where they would use a torch on the wood to create a black type spot/stripe pattern with singed wood. Personally I think it looks awful. But to each his own.

 

[ebb]

The stock finish was original from Japan. The black marks are all smallish 1/4 inch wide 1/2 inch long at the most. I am thinking this is some kind of mold or mildew that grew under the original finish or where there was damage to the finish and some kind of growth got to the wood. bleach may help.

 

[ebb]

I tried bleach and paint remover on the black marks and no joy on either. I have no idea and they are to deep to sand out.

 

[Dimner]

I tried bleach and paint remover on the black marks and no joy on either. I have no idea and they are to deep to sand out.

Crazy idea... try acetone. But even if you do find the right solvent, I doubt you will get it fully out. Another thought is that it might be some form of 'spalting'.. not sure if that term holds up for all woods, but spalted maple has natural discoloration made by nodes or veins of fungus discoloration. Personally I have always loved the look of spalted maple. But I have also seen maple called 'spalted' that was really just discolored lower grade woods.

Your stock could have been part of a batch of wood blanks that were milled, dried and stored at sub optimal conditions and were stained at the cellular level.

 

[ebb]

Spalted maple is very cool especially for turners. I have no idea what has made these but it looks like some one took a magic marker and drew them on. I will try acetone to night. I am thinking they are just going to have to stay, Ive already done more to this stock than I feel comfortable with. I do want it to be as original as possible. My taps came and someone on gunboards is sending me an original front action screw. The handguard had two splits in it that I glued up last night.
Real collectable guns have a certain percent of finish from the factory, the more they have the more they are worth. This gun was in such bad shape it will have zero percent meta and the stock has been stripped.

 

[SBS]

If acetone doesn't work, try oxalic acid. Works on dark streaks caused by rust. May need several applications and need to rise thoroughly before finishing.