Disassembly/Reassembly of the Steyr AUG Bullpup, Part I

In this particular case I must say I’d like to have been a fly on the wall or the guy with a tape recorder in the unmarked van parked outside eavesdropping as the committee meeting to outlaw "assault" weapons was in progress. I can hear it now: "It’s a military rifle." "True, but this one isn’t fully automatic." "Maybe so, but it still looks bad. Can’t have that sort of thing. Better ban it." That’s an approximation of how it might have sounded, folks, when the Steyr AUG was banned back in 1989.

It wasn’t the only gun to make the list after a similar in-depth "discussion." I wonder if the decision would have been different if Steyr had called its AUG something else. Nah, what the letters stand for wouldn’t have changed committee minds. Spelled out as Armee Universal Gewher would probably have added the words "Too German" to their decision and if Steyr had named the rifle after its configuration, Bullpup, those sitting gun "gurus" would have banned it for fear of rabies.

There may be a few among you unfamiliar with a Bullpup configuration so allow me to expound. It is a shoulder firearm in which both the action and the magazine are positioned aft of the trigger adjacent to the user’s face and lacking a conventional butt stock. What is gained by this set-up is a twenty-fi ve percent shorter overall length for the same length of barrel, significant weight savings and improved handling in tight quarters. The configuration itself isn’t new.

It was first employed in rifles and carbines as early as 1901 before being applied to semi-automatics circa 1918. The Steyr AUG of 1977, having overcome problems with this configuration among left handed shooters by allowing both bolt and ejection port cover to be readily switched to left-hand ejection, is often considered the most signifi cant "pup" and was employed by the armed services of more than twenty countries.

If you’re really interested, a complete list of rifles of this design guns can be turned up by telling your search engine to go find "Bullpup." At any rate, with thanks from the many fans of the design and an apparent enlightenment amongst gun banners on this side of the pond, Steyr Arms has re-launched its once prohibited AUG as the AUG/A3 SA USA. Basically, the rifle could be considered a proud descendant of the 1977 AUG. It is that and more.

While it remains a handy, gas operated rifle known for a locked action, reliability and quick change barrel, its established reputation for accuracy has received a kick upstairs. This benefi t has come about as the result of a stateside partnership between Steyr and Sabre Defence Industries.

You may recall the article appearing in our November 2007 issue featuring the Sabre XR rifle, an AR-15 clone whose bore dimensions are held under Mil-Spec of plus or minus 0.0004 and whose receivers are CNC machined from forgings of 7075-T6 aircraft aluminum. The XR is chambered from the commonly used .223 and the uncommonly used, so far, Grendel 6.5mm. The round, invented by Bill Alexander of Alexander Arms, totally dusts off the 5.56mm in terms of long range performance with half the recoil of the 7.62 NATO.

For those enamored of the big bang, Mr. Alexander has also created a monster called the .50 Beowulf. The rifle to shoot it is built for him by Sabre, available only from Alexander Arms and, except for the size of the hole in its barrel, appears to be an AR-15. When I asked the inventor how his sales for this setup

were doing, he responded with typical British understatement, "Having a distinctly discouraging effect on the intents of modern day Pirates of the Caribbean, they are doing extremely well, thank you, amongst defensivelyminded yacht owners in the Southern United States." Having seen the Beowolf, I can understand why. You may find it enlightening to visit AlexanderArms.com. I return to the Steyr/Sabre Defence partnership.

The meticulous Austrian engineers having oversight of AUG/ A3 production must have realized so much respect for the materials used and precise tolerances held to on the XR that Sabre was their choice to produce the receivers and barrels for the new AUG. I’m claiming no credit due my rave notices in the 2007 article, but nice going you Tennessee Volunteers!

About this Bullpup being produced "over there" and over here, it is chambered for .223 Remington and wears A an interchangeable, chromed lined from breech-to-muzzle barrel available in the shooter’s choice of 16 or 20 inches. The gas piston assembly is enclosed in a tube on the right side of the barrel. This assembly includes a regulator with two settings. One is for normal use and the other allows an increase in gas flow if the rifle becomes very dirty or must be operated under extreme cold conditions.

I have been told by one AUG/A3 owner that after a couple of thousand rounds he has never had to ask the rifle to perform under other than a "normal" gas flow setting. It still exists, none the It takes a strong thumb to get ‘er done. All its inner orifices can be cleaned out with metric drill bits. Aless, for those not equally inclined to clean a gun after shooting it or who just adore going afield in below zero temperatures prodded further downward by severe wind chill factors.

Whichever model of behavior fits your AUG/A3 customer, here’s how to approach the rifle. First, field strip the rifle. As always, the chamber must be empty and the safety "on" along with your eye protection. The AUG/A3 owner’s manual takes its reader pretty far into the gun but when was the last time you had an owner’s manual brought in by the owner when delivering their gun for service or repair?

Fully expecting that no-show habit to continue, I’ll take you through the pages you’d otherwise never see. There is no single schematic of the A3 so I’m forced to indulge your patience by referring to each separate schematic of a specifi c subassembly as required. I realize that is a bother but it’s the best way.

Of course, there’s nothing prohibiting you from making a copy of each one along with the appropriate parts list, assembling them on a larger sheet of paper and making an all-encompassing chart to retain for your unique and exclusive use. Be mindful of this: Right out of its case, there is absolutely nothing even slightly loose in an A3. I hope your finger strength hasn’t abandoned you. And away we go.

Grasp the front pistol grip with one hand, the magazine with the other and depress the mag catch to release the component. Maintain your hold on the pistol grip. With your free hand, pull the cocking handle fully to the rear and lock it there with a clockwise twist. With the same hand, push down on the barrel locking pin while simultaneously turning the forward grip clockwise. Referring to the Housing Group schematic, remove the barrel from the housing group.

Move your right hand from the front to the rear pistol grip. Release the cocking handle with a counter-clockwise twist. Press the rifle butt against your body and push the housing lock through from left to right. Slide the housing group and gun lock forward and out of the stock. Hold on to the housing and pull out the gun lock. Position The pin (A) is rotated clockwise and pops to the rear. the butt with its thin end downward and facing away from you.

There is a marked position, a large dimple in appearance, on the butt’s wider upper surface. Press down on it with one thumb while pressing inward on the retaining bolt with a free digit or two. Pivot the butt plate to the rear and off. Maintain the present position of the butt. Place one thumb over the rear of the trigger mechanism. Press inward on the retaining bolt lock with the free digits then back out the retaining bolt. Withdraw the trigger assembly.

This suffi ces for a basic clean up but in case the rifle is beyond basic cleaning you have to go further. Hold the barrel by the forward pistol grip. Press the gas regulator head down and turn it clockwise until its slot aligns with the nose of the gas cylinder. Should the gas head be fouled stuck with pollution you can use an empty cartridge case or the retaining bolt as a tool for depressing and turning it.

In these badly polluted cases, squirting some good quality solvent into the rear of the tube should, after a few minutes have passed for the solvent to do its thing, enable you to push the gas piston out from behind When making your own wire hook tool for fitting the barrel grip lid cap use spring steel wire. Awith the right guide tube of the gun lock. After that, removal of the spring is apiece of cake.

Speaking of guide tubes brings me to additional stripping of a gun lock that has tried to exist and function under the extreme dirty conditions that can accumulate in the gas system. Grasp the lock assembly by its slide and place it fl at on your bench with the hole in its top facing upwards.. At the back end of the slide you’ll see two tabs. Steyr refers to what they’re attached to as an "anti turn device." Squeeze the tabs together and rotate them up to align with the top hole.

Turn the end of the firing pin counter-clockwise with the fingers of your free hand. It will jump out all by itself and you can remove it. You still have one thumb handy. Use it to push the bolt slightly to the rear while using a digit from your other hand to press down on the bolt control until the bolt moves freely to the front. Back off pressure on the control and withdraw the bolt. The slide lock sleeve and spring ought to come out with it. If not, go fishing for them.

The cocking piece is slid downward to remove it from the rear of the slide.

Steyr AUG Barrel Group (Speci cations subject to change without notice) 1 Barrel, Sub Assembly 2 Gas Regulator 3 Barrel Grip 4 Lid, Barrel Grip 5 Spring, Barrel Grip 6 Pin 7 Flash Eliminator 8 Nut 1 Housing Sub Assembly 2 Plunger 3 Spring 4 Button, Sub Assembly 5 Grub Screw 6 Pin 7 Front Sling, Sub Assembly 9 Retaining Ring 10 Piston 11 Ring, Piston 12 Spring, Piston 17 Bayonet Holder 18 Screw 19 Nut Steyr AUG Housing Group (Speci cations subject to change without notice) 8 Button 9 Spring, Button 10 Pin 11 Body, Cocking Slide 12 Pin 13 Spring, Cocking Slide 14 Spring, Connecting Bolt 15 Connecting Bolt 16 Pin 17 Link Piece 18 Spring, Link Piece 19 Grip, Cocking Slide 20 Pin 25 Upper Part Picatinny Stanag

Steyr AUG Gun Lock Sub Assembly (Speci cations subject to change without notice) 1 Slide 2 Plunger Spring Lock, Long 3 Spring, Lock Long 6 Thrustpiece, Left 7 Thrustpiece, Right 8 Bolt, Lock 10 Extractor Steyr AUG Butt Group (Speci cations subject to change without notice) 11 Pin, Extractor 12 Spring, Extractor 13 Ejector 14 Spring, Ejector 15 Pin, Retaining 16 Slide, Locking 17 Pin, Control 18 Spring, Slide Locking 1 Butt Sub Assembly 2 Plate, Bu er 3 Rod, Guide 4 Bu er 5 Screw, Trigger 6 Washer, Trigger 7 Trigger 19 Pin, Firing 20 Sleeve, Spring Slide Lock 21 Cocking Piece 22 Control Pin Retaining Pin 23 Roller, Slide 24 Pin, Roller 25 Spring Loaded Firing Pin 26 Sleeve, Spring Loaded Firing Pin 8 Nut, Trigger 9 Sear 10 Spring, Catch Safety 11 Catch, Safety 12 Housing Lock 13 Spring, Housing 14 Catch, Magazine 15 Bolt, Magazine Catch 16 Nut, Magazine Catch 17 Spring, Magazine Catch 18 Butt Plate Sub Assembly 19 Lid 20 Ejection Lid, Inside 21 Ejection Lid, Outside

A few words of warning regarding a badly fouled A3. The rifle has many polymer components. The trigger mechanism is loaded with them. Harsh cleaners, such as brake drum and or carburetor cleaners, can put a real dent in compacted fouling, however, these types of cleaners should never be used on a polymer unless you have been assured by factory technicians that they will not weaken or actually melt the polymers employed in the construction of the gun.

A product resolving the quandary and saving you long distance charges has been mentioned here in Tech Topics. Dunk-Kit allows you to soak a polymer component, large or small, in it for days if necessary. No harm will come except to the encrusted deposit you are trying to remove. The gent who came up with Dunk-Kit is a member of the American Pistolsmiths Guild and a past Pistolsmith of the Year.

You can order a small bucket, a medium bucket or barrel of his brainchild at Detailed Disassembly I’ll try and make things easier for you from here on out by eliminating the need for your eyes to dart back and forth to the individual schematics and parts lists. I will instead limit instructions by the part numbers and the schematic of the section being worked on. Starting with the Barrel Group schematic, the gas system should be removed from the gas tube as previously described.

You’ll need a 200 gram fitter’s hammer, a 4mm pin punch and a hook for reassembly. Add to those a double open-end 19 x 22mm wrench, a small blow torch and some Loctite 648. The hook is pictured elsewhere and can be fabricated from drill rod stock. It will be used to reinstall the spring (5) in the barrel grip (3). Note the lid (4) on the grip. It’s the spring-related part and can fly when you drift the grip retaining pin (6) downward. Whatever, remove the grip lid and spring from the grip.

With the torch, heat up the flash eliminator (7) and nut (8) to 482 degrees Fahrenheit. Tempilaq, from Brownells, can be used to alert you when the desired temperature has been reached. There will also be a small amount of smoke. The heat is required to defeat the integrity of the Loctite the factory has applied to the eliminator and nut threads. Note that both are left handed. Loosen the nut with the open-end wrench and then back off both the flash hider and nut.

Turn your attention to the regulator (13) of the gas system and gather together the following twist drills: 1.6mm, 2.1mm, 3.2mm and 8.0mm. These will fit every orifice in the regulator and can be used like a reamer to clean them out if major fouling is present. Failure to eliminate this fouling will assuredly result in feeding and/or jamming problems.

As for the bayonet holder (17), I doubt your customer will be using a pig sticker even when hunting wild boar so remove the holder by backing the screw (18) and nut (19) totally off. The cocking slide assembly will require your fitter’s hammer, 3mm punch and the hook you made from drill stock. Drift out the pin (20) from the cocking slide grip (19). Separate the grip by pulling it off the link piece (17). Push through the pin (16), remove the link piece and link piece spring (18).

Pull back and swivel out the slide cocking body (11), punch through its pin (12) and remove the cocking spring (13) with the selfmade hook. Refer to the Gun Lock schematic. You’ve already been through separating the bolt from the rifle in the field stripping section. Now I’ll start taking down the bolt. The fitter’s hammer remains as a tool to be aided and abetted, this time with a 2mm pin punch and a 6.5mm screwdriver. Addressing the extractor (10), push through its pin (11) with the punch.

Being careful not to drop the extractor, remove the extractor spring sub-assembly (12). The ejector pin (15) is located immediately aft of the bolt lugs and should be positioned uppermost before drifting it downward with the pin punch. Do not remove the punch. It must remain in place to prevent the ejector (13) from escaping into who knows where from the bolt head. After you have that possibility eliminated, remove the punch, pull out the ejector and its spring (14).

The only two items remaining in the bolt body are the bolt control pin (17) and its retaining pin (22). Insert the screwdriver into the control pin hole and push out the retaining pin. If the shooter is a southpaw you’ll need to change from right hand to left hand ejection. Refer to the Butt Group schematic and have a screwdriver with a 3.5mm blade on hand. There is provision for an ejection port on both upper sides of the butt and two components occupy either.

One is an outer cover (21) and the other is an inner lid (20). Use the screwdriver to lightly lift the front end of the outer cover while pushing its back end forward with your opposite thumb. When you remove the loosened outer cover the inner lid will drop down into the stock and can be removed from the magazine well or ejection port. In this switch, the inner lid is inserted first from inside the butt and held in the port opening while the outer cover is slid in from the rear to engage it.

A left-hand bolt is required to complete the change and is available from Steyr, requiring no check of head space after installation. At least what Steyr says. It does seem the tolerances being held by the Austrians are so precise there is never a need to be concerned about headspace. Me? If I were making a right-to-left ejection switch you can safely bet I’d pop in GO and NO- GO gauges before handing the rifle back to its owner.

Perhaps I tread too cautiously but I’ve never made a bolt change that didn’t include a check of head space, function with dummy rounds and test firing with live ammo. With every respect for Austrian precision, I never will. AG