Type 38 Safety Issue

[browningautorifle]

Since you have two, take them both apart and compare the pieces

Exactly, should give you a clear picture. Bet you don't even need to make detailed measurements.

[MLMaier01]

I have discovered something ever so curious. My sporter 38 is a Koshikawa with the large protrusion type safety. My mil-spec is a Mukden which all had the small protrusion. On a whim, I installed the large protrusion knob on my Mukden and it locked up the bolt completely. In fact the non-matching safety knob worked perfectly. The same cannot be said of the small protrusion safety knob on the sporter though. In fact, the small protrusion knob will not even engage at all. This is a bizarre set of circumstances.

[AGB-1]

Did I not point this out in post #2? About the differences in safety knobs?

[Aragorn243]

Did I not point this out in post #2? About the differences in safety knobs?

You may have pointed it out but you continue going on the assumption the safety he has is not the correct one which he has pointed out numerous times that it is matching to the rifle. It also worked before he cleaned it.

[vintage hunter]

Did I not point this out in post #2? About the differences in safety knobs?

All you pointed out really was a misleading post on another forum and a link to an ebay auction for a book the guy used as referrence.
What the guy at gun boards is saying is there 3 different knob configurations and that they were made by at least 5 different arsenals to, I assume, inform the OP that if he's looking to keep his rifle "correct" type and manufacturer matter. Not once does he say the different types or arsenals are not interchangeable.
In fact post 22 above proves they are interchangeable.

[MLMaier01]

To a degree. The safety knob from the Mukden will fit on the bolt from my Koshikawa sporter, but it will not engage. I think this has something to do with the dimensions of the protrusion on the bottom. I measured them, they are both .230 wide, but the protrusion on the Mukden knob is taller. I have ordered another small tang safety knob to compare and contrast and see if this characteristic is common to all small tang safety knobs, or if the one on mine is defective in some way.

[vintage hunter]

To a degree. The safety knob from the Mukden will fit on the bolt from my Koshikawa sporter, but it will not engage. I think this has something to do with the dimensions of the protrusion on the bottom. I measured them, they are both .230 wide, but the protrusion on the Mukden knob is taller. I have ordered another small tang safety knob to compare and contrast and see if this characteristic is common to all small tang safety knobs, or if the one on mine is defective in some way.

Arisaka safeties, like mauser, Springfield, Winchester 70 ect.,sometimes require fitting before they'll work smoothly. The Mukden knob could easily be made to work in the Koishikawa if need be.
Theres something very simple that you've overlooked keeping the original safety from working properly.

[mmppres]

With all Jap rifles an most military rifles.You must remember that under the condition of war parts were made to be interchangeable. Only small hand fitting should be needed. In the field one part didnt work they grabbed another. Be thankful that you can get another safety knob. I must watch the firearms we have for sale at gun shows due to theft of those plus firing pins. We lost 2 at the last big show.