Identifying source of barrel on Type 44 target rifle

A couple years ago I acquired the rifle pictured below. It is a Type 44 receiver and bolt on a hefty target style stock with the stock wood filling up into the magazine well (single shot).

The barrel on it was originally something else as can be seen by the front sight dovetail. and it is sleeved for 30-06. The external diameter is .786" and length to the reciever is 22 3/4" if that helps at all.

I'm hoping someone on here can help me figure out what the barrel was originally?
Also if anyone has seen a creation like this before I'd be interested to hear more about it.

http://imgur.com/a/aNScIjl

Link to album in case the images aren't showing up here Arisaka target rifle

Looks like a raw barrel blank from any one of the main barrel manufactures.

"...barrel blank from any one of the main barrel manufacturers..." Yep. No marks on it at all? That is unusual as most of the aftermarket barrel makers want everybody to know who made it. You can't tell anything by the dimensions though.
Isn't "sleeved for 30-06" though. It was threaded to fit the receiver. Using a Japanese receiver is unusual too.
"...wood filling up into the magazine well..." That's unusual too. I'd bet the rifle was built by some guy who apparently knew what he was doing.