Shugyosha

Hunting arrows would typically have a bladed/ barbed head (like the odd one above) as they kill by cutting rather than by punching a hole in the prey. War arrows tend to be designed to punch through armour, hence the lozenge and similar shaped heads. Consequently, I’d agree that these are target or practice arrows as they’re roughly comparable in shape to western heads used for target archery.

Hi Maxime, the nengo may be Keian 慶安 and, if correct, the second year would give you 1649. Lovely blade!

But if you did that it wouldn't be the Dan show would it?

Hi Max, That's a really lovely feature and a mark of the quality of the piece. I've heard two explanations for the reasons for udenuki ana (sorry if this is mentioned above, but I've not read to the top of the thread): for a lanyard to attach the sword to the wrist so it didn't get lost in the heat of battle or to attach a fine thread between the tsuba and the saya. The point of this being that, should the owner be tempted to draw his sword in anger, there was enough of a pull on the sword to give him pause for thought and reconsider the action that he might have taken spontaneously. Obviously the thread would not be so strong as to prevent the sword from being drawn should the need arose. Both of these reasons my be apocryphal and I can't reference them so treat accordingly.

Hi Luca, Luckily all the upvotes will compensate for it.

It crops up in a couple of Chinese place names too, so perhaps something related to the occupation? Another guess though.

Not sure this will be of any help in the context of a naval dirk, but: https://jisho.org/search/蘭

Hi Mark, 以地金下 Motte jigane shita… Made with “jigane” which Jisho defines as unprocessed ore or an ingot. Then the kanji “shita” meaning below or beneath which I guess may be part of the smith’s name and which probably has other readings. Hope that helps some.

Yes, it's the "Seki" stamp. https://www.militaria.co.za/nmb/topic/7476-use-of-the-seki-stamp-and/

It doesn't look like it goes through the hamon so I'd say that it's not fatal (assuming that what I can see from the photos is actually the case). It's not very pretty but I don't think it's killed the blade. I'm working on the premise that something is either fatal or not, rather than there being degrees of fatal.

Perhaps to bring the balance point closer to the tsuka? I can remember one sword l that was quite long, that unfortunately I can’t reference, where there were metal strips in the grip presumably for that purpose. Or maybe because an outsize blade needs something to absorb the unusual shock of a strike? Just guessing.

Looks like it has the ho (ホ) armoury?? stamp on the nakago mune too, the meaning of this is beyond my knowledge but the gunto guys will be able to provide that information.

My oeil was tromped too.

I don't actually know the answer but a lance penetrating a body deeply can drag the lance from the cavalryman's hand and even the rider from the horse if he hangs onto it and his techique is off for any reason. Perhaps it was thought that limiting the potential to penetrate might mitigate against this problem?

Good spot Sam, For the record, I think it's this : 備州長船佑国 ...but the 佑 kanji which can also read "suke" doesn't come up in Sesko's compendium or an on line search for Bizen smiths. Luckily Sam replied otherwise I would have assumed it was me and kept on searching.