tool blocks mounts.
This fixture clamps the tube to keep it from turning. The reamer you make it can be counter bored to a
depth of 3/4 inch to accept the 1/2-inch oil line tube. This should be sweated together with soft solder.
This is done by cleaning up the 1/2-inch counter bore. Then tinning it and the 1/2 tube, heating the tube
and reamer shank together, slipping it into the counter bored hole rotating ft a few times and letting the
solder coot.
You will put the barrel in the lathe with the muzzle end in the chuck. Thus the reamer will be started at the
chamber end, and pulled towards the muzzle. On the roughing and finishing the reamer will not come out
all the way out of the barrel. The finish reamer will be stopped with the choke about 1 inch from the
muzzle. You must hand feed the finish reamer for a few thousands out the choke. When having reached
the desired length, disengage the feed and while the machine is still running back out the reamer.
In reaming the barrel the lathe should be in the slowest back gear position. You will have to find the
best-feed rate. On the roughing reamer you will have to use the slowest feed as you are removing a
greater amount of material.
WATCH FOR REAMER PLUGGING
One thing that is necessary is that on all tools, is that they must be attached absolutely solid and straight
to the reamer oil tube. If not this can cause you a lot of grief in the form of ringed and rough barrels.
CUTTING THE CHOKE
Shotgun barrels are made from steel tubes and although they may be reamed to size with a series of
barrel reamers, such as those used on rifle barrels, they are usually finished bored and choked with a
long, four-sided, square reamer of 01 tool steel, ground to size on a surface grinder. These reamers are
10" to 12" long and have a tapered lead at the front end, about 1" long on the finishing reamer.
The driving rod for these reamers is brazed to the rear end of the reamer, the opposite end from that
which has the tapered lead, and the reamer is pushed through the bore as the barrel tube revolves.
A wood packing strip, turned on one side to the contour of the barrel bore, is placed against one side of
this reamer, its full length. Strips of paper are placed between the wood strip and the boring reamer to
cause it to cut larger after each trip through the barrel.