Will a 6.5x68 fit? I have an action that is in very good condition. Intact Mum. I want to build a sporter with a flat shooting cartridge and open sights. I don’t want to cover up the crest.

6.5 x 50 Type 38
7.7 x 58 Type 99

I'd say it's 18mm too long. Probably too long for the 99 as well.

Well that sucks.

A .260 Rem will fit. What distance are you planning to shoot it? The Swedes shot their 6.5x55 Mausers at pretty long distances with open sights.

I think the Swede would be too long also. 6.5 Creedmoor is a shade under 49mm. Very nice action you have there.

The opening in a type 38 Arisaka is 78mm, probably the best you can do is a 6.5-284...as long as you don't use too long a projectile...overall length on a 6.5-284 is 82mm.
I have one in the standard 284.

Roger

Hmmm…6mm/284. Use lightweight bullets for a flat shooting SOB. Sounds cool.

260 AAR or a 6.5/257 Roberts. They have been built on Arisaks for years.

I have a 260 AAR in a Type 38 Arisaka. It feeds properly. The 260 AAR is a 6.5/257 Roberts blown out. With proper loading and at least a 24 inch barrel, velocities will be close to a 25/o6.

Either the 260 AAR or 6.5/267 Roberts would be a good conversion, subject to your intended use.

Geoff