Workbook

*A "Gunwriter Whore" is someone who writes glowing reviews of every free gun he gets, to

insure he gets more and to insure the manufacturers continue to spend big bucks on

advertising in their magazines. Every gun reviewed is the best he's ever seen. Gunwriter

Whores use terms such as "new gun syndrome" to rationalize favorable reviews on guns that

won't function out-of-the-box and they try to convince their readers that every gun should

require several hundred rounds of "breaking-in" or tuning by a master gunsmith before it

can be expected to perform its basic function of going "BANG!" every time the trigger is

pressed.

Typical 3M brand masking tape is 0.005" in thickness. Therefore, if your bolt closes on a NOGO

gauge (1.6340"), you are still okay. If it closes on a NOGO plus a piece of masking tape (1.6390"),

you are unsafe (FIELD is 1.638"). If it closes on your field-expedient gauge made with a National

Match Cartridge (we are assuming a National Match case is the 1.6300" GO minimum) and a piece

of tape (approximately 1.635"), then you are okay, just on the long side of acceptable. Two pieces of

tape (approximately 1.640") are unsafe. Remember that these measurements are for the FAL only and

do not apply to other rifles.

HOW DO I FIX SHORT HEADSPACE?

Short headspace is usually characterized by difficulty chambering. If you have a .308 finishing

reamer and a non-chrome-lined barrel, you can cut the chamber deeper until you reach the proper

dimensions. You can also remove material from the bolt locking surface, however I do not

recommend this because it precludes you from using a different bolt. The best way is to get a proper

sized locking shoulder.

Remove the locking shoulder with a #7 (7/32") roll pin punch. Using a flat head punch invites

slipping and scratching the receiver. You may be able to file the locking surface, but in all but the

hardest files, the metal will be too hard. Use the edge of a thin sharpening stone or 220 grit

sandpaper to remove material from the face of the locking shoulder. Follow the original angle and

remember that you are removing less than the thickness of a piece of masking tape between test fits.

The edge between the top of the locking shoulder and the face must be beveled, so if you remove

enough material to make this edge sharp again, sand it back down. Reinstall the locking shoulder

using a brass hammer or your pin punch. Insure you align the oval tab with its recess. The slightest

misalignment will make this brittle tab break. You can turn it with a wrench to align it prior to

seating it in place.

This method may require removing, fitting and reinstalling the locking shoulder several times. A

way to get it right the first time is to go to a machinery supply store and purchase steel dowel pins.

They come in .0005" increments on the expensive ones and .001" on the cheap ones. They are about

$4 each and you can get away with every other pin if you don't want to buy the whole set. Figure you

will need .256" to .264." Insert the dowel in the locking shoulder hole with a GO headspace gauge in

the chamber. Find the pin that just barely allows the bolt to close. Hone your locking shoulder to the

same dimension.

HOW DO I FIX EXCESS HEADSPACE?

Excess headspace means upon firing, the web of the cartridge case is not supported by the chamber,

This causes the brass to expand at the web, which weakens it. Extraction can then result in the base

of the case being ripped off. You can fix by finding a bolt and bolt carrier combination that fits, but

you will probably need to purchase a new locking shoulder. I have found that locking shoulders

measuring 0.262" to the locking face are large enough for most guns. Take this new locking shoulder

and follow the directions for short headspace rifles.