Barrel slugging question?

[snuffy1a]

Tried to slug two of my type 38 Japanese rifles. The first came out ok with a reading of .265. however the 2nd which is a type 38 carbine did not. The slug appears to be completely smooth all away around with a reading of approx. .258. It is as if the grooves were never implanted. Could the grooves be that filled in as to be the same height of the lands? Any suggestions would be welcomed. By the way, I was using a 00 lead shot from a shotgun shell.

[KenH]

When you look down the barrel do you see any lands/grooves? OR - does it look sorta smooth?

[rick/pa]

Did you clean the bore before slugging?

[Shooter6br]

Late Jap rifles were un rifled I had heard. Last ditch effort

[Ballistics in Scotland]

There were Japanese rifles made with cast iron receivers in the late stages of the war, and very possibly without rifling, but I believe they were for drill and training when crucial parts of the manufacturing facilities were overstressed due to bombing etc. They weren't intended for shooting. Very likely you have one of these.

There are other possibilities, though so far as I know they can be eliminated by establishing whether the bore is equally tight all along its length. Remove the stock and examine it with your fingers and a good steel ruler to see if it is ring-bulged. If a bullet loses its core, it is possible for the jacket to lodge in an existing ring-bulge (invariably made by a previous obstruction) or create its own as following bullets pass through it. Rifles have even been observed to shoot very well, with a short section of the bore made of gilding metal or nickel. But if the ex-bullet jacket has turned into a constriction it won't, and is dangerous to shoot through.

Once I tried reversing a duplex load by putting in the correct and mild smokeless load in an 88x60R Portuguese case, and filling the rather voluminous case with black powder. It did just what Dr. Mann achieved experimentally with sand in the early years of the twentieth century, by wrenching off the case neck, which vanished downrange with the bullet. I suppose a case neck could do the same as a bullet.

You should be able to feel in the slugging process whether the obstruction is localized. But for more precise information, try inserting a slug from each end of the barrel, just a short distance, and seeing if it comes back out that way at the same diameter.

I'm afraid I can't give you much good news on this one. If it is consistently unrifled I wouldn't trust the receiver to rebarrel until I had a really good gunsmith test it - and that means the sort who could do hardness or magnaflux testing if he feel it advisable. I can well imagine the factory having a conscientious Japanese geriatric who could finish receivers of bad metal perfectly.

[kywoodwrkr]

You might want to try and find out general date that the rifle was made.
There is a forum dealing in depth with Japanese weapons.
Google Banzai rifle forum and go from there.
Left side of receiver can often be deciphered to show where and when the rifle(in this case) was manufactured.
Good luck with investigation.