August 14, 2013

Disassembly/Reassembly of the Browning A-Bolt II

Here’s how to take apart any of the 22 models of Browning A-Bolt II rifles.

The original A-Bolt Hunter and its BBR predecessor had several things in common. Both were manufactured by Miroku in Japan, had detachable magazines under their floorplates, and adjustable triggers. They were both delivered to the store without sights unless otherwise specified, and neither was designed by John M. Browning. The BBR was a big, heavy action. The A-Bolt arrived in 1985 to change all that with a three-lug bolt and a short, 60-degree bolt throw. This allowed rapid cycling of the action, ample scope clearance, and a bolt handle engineered to fit the human hand naturally.

Further improvements to the Browning A-Bolt rifle, made around 1994, included an anti-bind bolt, a non-rotating bolt sleeve, and additional weight reduction without sacrificing the strength required for Magnum calibers. In 1999, an opening up of the action for clearance with the increasingly popular WSM calibers gave birth to the A-Bolt II and a long list of models and chamberings including the newest super-short Magnum rounds.

Fresh out of the box, an A-Bolt II barrel and receiver are coated with a factory-applied anti-rust compound. Before the gun is fired, this gunk should be cleaned up with snug-fitting bore patches, lint-free cloths, and a high-quality light gun oil.

Field Stripping

The magazine is empty, the chamber is clear, and the safety is off. Raise the bolt handle, depress the bolt stop, and remove the bolt to the rear. It isn’t necessary to operate the bolt stop for reinstallation, but the bottom bolt lug must be positioned as shown in the accompanying photo when inserting the bolt.

December 2003

Courtesy, American Gunsmith Magazine

Field stripped less the bolt, this A-Bolt II rifle is only one of 22 models available. Fortunately, all take down and go back together in the same manner.

Remove the barrel-mounting screw (#2), and withdraw the magazine floorplate (#40) with hinge (#34) and magazine (#33) attached. Back out the front and rear trigger-guard screws, remove the guard, and separate the action from the stock. It may be necessary to hold onto the stock or forend and gently tap the barrel down on a padded work surface to start the metal on its way out. At this time, the trigger assembly can remain attached to the receiver.

Move back to the bolt for a minute. When it’s slid back into the receiver, the ejector pin (#20) has to be positioned midway in the bolt sleeve (#16) recess. You might want to index the location with a felt-tip pen as I did for the aforementioned photo. It saves fumbling and possible surface scuffing.

Detailed Disassembly

Your recent experience with bolt removal will have familiarized you with the firing-pin sear (#25), also known as the cocking indicator. It protrudes from the bolt’s rear when the gun is ready to fire. Secure that portion of the indicator between protected or smooth vise jaws. Grasp the bolt handle (#5), pull toward the bolt head (#8) to compress the firing-pin spring (#27), and give the handle a turn counterclockwise. After the one turn, you won’t need the leverage provided by the bolt handle to continue unscrewing the bolt sleeve (#16) and withdraw it from the firing-pin assembly, leaving the latter in the vise. Get a firm, finger grip on the bolt shroud (#15), pull toward the firing-pin tip, and lift the shroud off the assembly. Drift out the firing-pin sear pin (#26) in either direction with a 1/8-inch punch to free up the spring (#27), firing pin (#24), washer (#28), and sear/indicator.

December 2003

Courtesy, American Gunsmith Magazine

Here, a punch has been inserted through the bolt-head key pin hole in the bolt head. When installed, the opening in the key pin must be aligned with the chamber to allow passage of the firing pin.

Align the bolt-head key pin (#9) with its large bolt-sleeve opening. Drive the pin down and out with your 1/8-inch punch, back out the bolt-sleeve screw (#16A), and withdraw the bolt assembly (#4). The bolt head is caliber specific, and can be pulled out of the assembly. You’ll see a “pigtail spring” (#23) sticking out the rear of part #8. That’s the extractor spring, and the extractor is also caliber specific. When you pull out the spring, the extractor (#22) will fall out. Hopefully, it will fall into your waiting hand.

The ejector assembly (parts #19, 20, and 21) is retained by its pin (#20). The pin drifts out right to left when the bolt head faces forward. So much for taking down the bolt, but there are several reassembly tips to be covered later on. And leave your protected vise jaws standing by as your third set of hands.

Now for the adjustable trigger assembly. It’s held to the receiver by a housing screw (#54), housing-screw washer (#55), and housing set pin (#56). The latter is a roll pin. Remove it first in either direction, followed by parts #54 and #55. By the way—and this is important—the bolt-handle lock (#6) hooks onto the safety (#57). When you remove the trigger assembly, don’t lose either part #6 or #57. These are restricted parts, as are all other parts closely associated with the trigger assembly. For that reason, I’d advise you not to disassemble it further. There’s no real need to do so anyway. If it’s dirty, soak it in kerosene or mineral spirits for a day or so, flush it out, and dry it with compressed air. If it needs adjustment, the necessary steps can be taken with the action still in the stock. The adjusting screw (#85) is turned clockwise to increase pull and counterclockwise to lighten it. The range is approximately 3 to 6 pounds.

December 2003

Courtesy, American Gunsmith Magazine

The arrow on this partially disassembled bolt assembly shows the bolt-handle notch into which the firing-pin sear must fall during reassembly.

The magazine can be removed from the floorplate by supporting the barrel at a downward angle, pressing the magazine latch (#3), and swinging out the floorplate (#40). Grab the magazine at its upper end, tilt it away from the floorplate, and carefully lift or slide it from the groove at the bottom of the plate. I think this is a nice little feature. It makes it possible to carry spare, fully loaded magazines afield, and rapidly replace an empty one by reversing the removal process.

If necessary for parts replacement, the magazine-latch assembly can be taken from the trigger guard by drifting out the latch pin (#38). Yep, it’s a roll pin. The magazine itself is best left alone beyond slight adjustment of the lips to correct any feeding problem. Why leave it alone? Part #44 that retains the magazine ramp (#45) is a rivet.

If you’ve tried to buy Browning A-Bolt parts, you may have discovered that the butt plate is among the restricted parts. Why, of all things, should a butt plate be restricted? Well, with the A-Bolt II, it’s because the factory takes extreme care to match the butt plate to the surrounding material (be it wood or synthetic). I guess they don’t believe a practicing gunsmith could do it as well. If you read Dennis Wood’s article in this issue, however, I’m sure you’ll have no problem with the task, but you’ll probably have to install an aftermarket pad.

December 2003

Courtesy, American Gunsmith Magazine

Still attached to the receiver, the right side of the trigger assembly is shown here to illustrate the safety/safety linkage that could easily be lost when the assembly is removed.

With regard to ordering other Browning parts, you’ll find that the key numbers on the schematic drawing on page 5 are not sufficient; you’ll need to know the actual Browning part number. Since so many parts are caliber-specific, a list of all part numbers would cover much more space than we have in these pages. You can, however, get a parts list by calling Browning (800/322-4626) or by visiting the Browning web site.

Reassembly Tips

All of these will concern the bolt and firing-pin assemblies. Open the jaws of your vise slightly wider than the width of the firing-pin sear. In the center of one end of a 3/4- x 2- x 3-inch hardwood block, drill a 1/4-inch-diameter hole 2 inches deep.

Position the firing-pin spring on the pin. Place the washer on the pin with its beveled edge to the rear. Slip the firing-pin sear on the pin with the colored indicator tab facing rearward. Tighten the sear in the vise. Align the sear pin holes and install the pin. Use the wooden block to compress the firing-pin spring with one hand and reinstall the bolt shroud with the other.

Make sure the vise still has a good hold on the sear. Again, compress the firing-pin spring with the block of wood and keep the pressure on while you fully screw the bolt body on the firing-pin assembly. Back out the bolt body until the point of the firing-pin sear aligns with the hold-open notch in the bolt handle (see photo). Then release the vise and allow the point to drop into the notch.

When reinstalling the bolt head, you have to hold the pigtail spring in its groove at the rear of the head or you won’t be able to insert the assembly into the bolt sleeve. If there’s a pain to working with the A-Bolt II, this is it. You can’t hold the spring in place from its back end. You have to go at it from the bolt-face side. It’s not getting the spring into the groove that’s testy; it’s holding it in place long enough to snap the bolt sleeve over it. A sturdy thumbnail seems to be the best tool to use, but don’t have a hissy fit and write to me if you break yours.

Oh, yes, once you have the bolt head in, don’t fail to position the hole in the bolt-head stop pin fore and aft to allow passage of the firing pin. Somehow, I have to believe that John Browning would have designed the “pigtail” aspect of the A-Bolt II differently. Meaning better.