Workbook

METRIC. Use your 12" mill file with the safe edge against the barrel threads. It is easier to

keep a long file perpendicular than a short one. Files cut only on the forward stroke. Cut

shoulder in four directions, making a square around the round barrel. Then file four more

cuts to make an octagon. Take it slow. A good, sharp, file can remove .0005"-.0010" per

pass and you will want to test fit each .001" inch. Use a magic marker (poor man's Dykem

layout fluid) to color the area you have cut. Screw the barrel on. Areas where the magic

marker has been scratched are your high points. File these high points flat. Cut again offset

from your first 8 cuts. Its better to angle the outside edge of the file about 1 degree up then

to angle it down, although perfectly flat of course is the goal. Repeat until barrel spins on to

correct point. If you remove too much metal, all is not lost. Using your brass hammer (or

very gently with a steel one) tap the shoulder all the way around, swaging the metal out. A

hundred moderate strikes are better than pounding on it. You can cheat here and shim it like

an inch gun, if you desire, but swaging will work fine.

Of course, if you have access to a lathe, the best way is to spin the barrel and shave .0005" to .0010"

at a time, test fitting until it indexes as described.

Unscrew the barrel and select the appropriate wrench. Screw the barrel in, and "crunch" the barrel

(100 foot pound minimum is ideal) the rest of the way so the front sight is at 12 o'clock top dead

center. You can use the gas cylinder and gas cylinder bush/rear support for gross alignment and your

tiny witness mark inside the cocking handle channel will help as well. Without the carrying handle,

it should screw into receiver without binding. If you have an StG-58 with the short brazed gas

cylinder you insert the gas piston and insure it

moves freely. Final alignment is verified by

attaching the lower receiver assembly and

sighting in on a light colored surface. You can

use a cheater bar for additional leverage. I

have found pulling upward on the wrench

gives more control than pushing downward.

Some recommend clamping the barrel and

turning the receiver with a receiver wrench -

but if you're not willing to pay to have

someone else barrel the gun, we can assume

you don't want to buy a barrel press either.

Also – turning the receiver makes it harder to see where top dead center is. If it won't turn far

enough, unscrew and take more material off the shoulder. If it goes too far, remove the barrel,

degrease, and peen the shoulder with a hammer all the way around. Screwing the old receiver stub

part way on will give some protection to the threads if you miss with the hammer.

You will have to choose whether to use anti-seize compound on your threads or to use a thread locker

or nothing at all. Anti-seize will allow you to turn the barrel a few degrees further under the same

pressure, as it keeps the metal from binding or "galling." Thread locker is useful on Israeli barrels

where the threads are recut and don't match perfectly with the receiver. Thread locker also is added

security if your torque level is less than 100 foot pounds (such as a barrel on the verge of timing too

far) and also makes tampering evident, as it requires heating to 300 degrees to melt the red or green

type.