Re-Barreling an M1896 Mauser

[Olle]

Rich,

I tried the setup in your third pic, but with a turned brass rod instead of a straight rod. I got the same side-to-side runout as when chucking it by the barrel band, but the up/down runout was now about .015. Seems like the bore is off center by maybe .007-.008 at the muzzle.

Anyway, the runout in your second picture is close to what I got in the very same location, so I guess these guns are not as precisely machined as I thought they were. That could make it iffy to get a new barrel centered, as you won't have any reliable index points. On the other hand: It won't be difficult to stay within Mauser's tolerances, a tape measure will probably do just fine...

[Olle]

BTW: For operations like this, I prefer to turn a rod and leave it chucked until I'm done. My Emco 3-jaw chucks usually stays within .001" TIR, but turning the rod right there and then will eliminate any possible runout caused by the chuck. I use a brass rod, and turn about 1/4" to a diameter that slips into the bore. Then I back off .001", turn another 1/8", back off etc so I get a stepped taper. This will usually get me dead center in the bore.

[sheepherder]

Originally Posted by Olle

BTW: For operations like this, I prefer to turn a rod and leave it chucked until I'm done.

I have done that in the past, but then I started marking my chuck center and mating it with a corresponding mark on the 3-jaw chuck. I also tighten the same jaw each time. Seems to work...

tell you what - that barreled extension up in the last post is an original C96 Mauser. Bore is a bit worn, but good rifling. Let me get my last re-barrel out and measure the runout on that...Stay tuned...

Ooowww...I'm not as good as the boyz at Mauserwerke...