Thursday, May 8, 2014

Sporterized Arisaka Redux Part 1 Dis-Assembly/Assessment

Back in April I posted about a sporterized Arisaka that I found at the Gun Show (Latest Gun Show Find).

I finally got around to taking the gun apart to see what modifications were performed and if the work was up to snuff. 
First I would like to go over a little history of the Japanese Arisaka.
The original design dates back to 1897, a Col. Arisaka Nariakira designed a gun using elements from other guns.
The type 38 was chambered in 6.5 x 50mm.
The Type 38 was revised to include elements from the German 1898 Mauser. 
Beginning with the introduction of the Type 92, The Arisaka was chambered in 7.7 x58mm, as were subsequent models, the Type 99 being the last.

The 7.7 x 58 mm has ballistics similar to  a 308 Winchester (7.62 x 51mm).
Here is a picture showing the 7.7 Jap with other similar cartridges:
From Left to Right: 7.62 x 39mm, 7.62 x 51MM NATO (308 Win), 7.62 x 54R, 7.7 x 58mm Jap & the 30-'06 Springfield

There were some 2.5 Million Type 99 rifles built at the 8 arsenals throughout Japan between 1939 and 1945. 
My rifle was made at the Nagoya Arsenal, it has the later bolt, but doesn't appear to be a "Last Ditch", so I am not sure exactly when it was made.
The "Last Ditch" rifles were made at the tail end of the war, when resources were getting scarce and time was running out. The guns were hastily put together with ersatz parts and sometimes shoddy workmanship. 

Each rifle was marked with the symbol of the Japanese Emperor, the 16 pedal Chrysanthemum flower (aka "the Mum"). Originally the receiver looked like this:
 Most of the "Mums" were ground off before the guns were surrendered to the U.S. This is what mine looks like:
You can see where the Mum was ground off.

Sporterizing surplus military rifles became quite popular in the 1950's. 
Commercial hunting rifles were expensive, while the abundant surplus guns like the Mauser, Springfield and Arisaka were dirt cheap, like under $20 (sometimes even less)!
I'm not sure when this gun was sporterized, but I would guess sometime in the 50's or early 60's.
This is what the gun originally looked like
Here is an exploded view


In the 1960's Gun Writer and Wildcater P.O. Ackley tested receivers from surplus rifles, Mausers, 1903 Springfields, Lee-Enfields, P-14s, Krags and Arisakas (both types 38 & 99) were proof tested. The Arisaka type 38 was the strongest with the type 99 coming in close second. Rumors are the pressures were in excess of 120psi. 

So I took the gun apart to see how it was modified:

Here is the in-letting in the stock, looks pretty good, whomever did the work was patient and only took out what was needed.

Here is a picture of the safety that was added
Here is a picture showing the Safety catching the back of the trigger:

Safety On
Safety off
The safety has a nice de-tent that holds it in place.

Here is what the magazine floor plate and trigger guard look like disassembled.
 I have a laundry list of things I want to fix. The trigger guard/floor plate needs to be refinished. I will thin the trigger guard during the process, giving it a more graceful taper from front to rear.

I will also taper the rear of the magazine follower so that the bolt can be closed when empty.

I will need to remove the trigger to tighten it up and reblue the gun, so I will need to remove these pins (circled in red) and create new ones or find some bolts or screws to put it back together.
Here you can see where the barrel was touching the wood, some of the bluing is worn away.



This may or may not affect accuracy when the weather is warm and dry, but when wet and cold (aka Hunting Season) the wood can easily swell and put uneven pressure on the barrel, affecting accuracy, or at least that is the theory. I will remove some material to "free float" the barrel and then glass bed the stock to prevent any "swelling".







references
The Firearm Blog
Wikipedia
Lawrence Ordnance
Milsurps.com

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