Convert Browning’s Manual Safety to Automatic on the Superposed

The history of the safety as a device for preventing an accidental discharge starts long before the powder era. Even ancient wall-piercing and ballistic machines had them. Their role was not only the prevention of personal injuries, but also to avoid the waste of labor invested into loading these machines. One other often-overlooked role of safety is the prevention of self-disclosure due to an unprepared and unwanted shot.

The complexity of safeties on mechanical weapons has grown over the years, and reached a quite sophisticated level on crossbows of the late 14th century. The appearance of the powder and primitive firearms did not eliminate the need for an effective safety; on the contrary, the personal danger of an accidental blast grew, as did the danger of giving away one’s position by unintentional noise.

Since then, safeties on guns went through an evolution of changes, with many famous gunmakers competing for the best designs. From early on in this process, there was an effort to devise a reliable automatic safety. The principle behind the automatic safety is that the weapon goes on safe before or at loading, independent of any action on the part of the shooter. Thus, the just-loaded gun is always on safe, and requires the shooter’s action to make the gun fire. This way, one can not forget to put the gun on safe.

Well-known automatic designs include Joe Manton’s "gravitating safety" which appeared in 1815, Purdy’s grip safety, and W. W. Greener’s "butt safety bolt" introduced in 1879. At the same time, some prominent gun enthusiasts expressed opposition to the automatic safety. Interestingly enough, Greener was among them, even after developing his own version of the automatic safety. The other prominent opponent of the automatic safety was Elmer Keith. His opinion is so radical that it’s worth quoting here.

The following quotation is from his book Shotguns by Keith: Automatic safeties, which go on "safe" whenever the gun is opened, area fine thing for the beginner or the man or woman who hunts but seldom, as the gun then thinks for the hunter. For the experienced hunter or shooter, automatic safeties area damned nuisance and should never be tolerated any longer than it takes to get yourself to a gunsmith and have the link removed, making the safety nonautomatic.

The dispute between advocates of automatic and manual safeties does not seem to be that sharp nowadays. However, the popular opinion remains that automatic safeties area must for hunting and optional at the shooting range. This attitude is understandable, since, during a hunt, an accidental shot can cost the life (of a human); while, at the range, an automatic safety may cost the score.

Be that as it may, as I mentioned in my article on converting the safety on the Daly over/under in the September 2003 issue, I am converting as many Figure 1.

automatic safeties to manual as I am converting manual to automatic. The Browning Superposed is a well-respected and popular shotgun, and many older shooters will eventually pass this gun along to their children and grandchildren. This helps to explain why some of these shooters are interested in installing an automatic safety on the Browning Superposed, as well as Miroku’s Charles Daly and other guns. The conversion of the safety to automatic on the Charles Daly was described in my previous article.

In fact, that article was introductory to this one, since I intended to bring the issue up and discuss it for some other guns before touching on the most popular shotgun in America, the Browning Superposed. Weapons designed by the genius John Moses Browning are very difficult to alter without spoiling them. It’s also a great responsibility for any gunsmith to try to upgrade the function of those weapons.

The major mechanical principles of the Superposed were laid down by John Browning, but the gun still was not in production at the time of his death in 1926. The responsibility for finishing the design and starting the production were acquired by his son, Val A. Browning. The single largest problem for Val was the design of a reliable single-trigger mechanism. After a number of attempts, a successful solution was found and patented in 1938. This latest design combines the selector mechanism with the safety-button.

The distinguishing feature of this design is the utilization of the leafspring. Later, the same safety-selector principle with a leaf-spring was implemented on Miroku’s Charles Daly, and I’ve used essentially this same procedure for installing an automatic-safety conversion on this Miroku gun. I’ve wondered what John Moses or Val might have said about this safety, and what kind of arguments they might have had for implementing a manual safety rather than an automatic.

I could not, however, find any references to the matter. In any case, in Figure 2. the post-Browning period, there were attempts to provide an automatic safety on the Superposed. Some involved complicated mechanical additions to the action, requiring significant wood removal and sophisticated milling of the frame. None, I believe, were as simple as the procedure I’ve developed.

When I first started thinking about this conversion, my focus was on avoiding any changes to the original parts, including the wood of the stock around the action. My intentions were good, but there is no spare space inside the action at all, and the conversion of the safety into automatic assumes that some additional parts will be introduced into action for transferring motion from the bottom bolt to the safety button.

The bottom bolt is the only part that moves backward with turning the top lever for opening the gun. The safety button also has to move backward. This is why the bolt is the best candidate for feeding this motion. The other solution would be to mill the frame for reaching the column of the top lever and feed the motion from it, but this change to the original frame would be too dramatic and not in keeping with my original intentions.

Below is a step-by-step description of my conversion of the manual safety into automatic on the 20-gauge Browning Superposed. This action is the smallest, of course, and the most difficult to deal with. The Main Principal This conversion uses the tiny spaces between the hammers and sears for transferring motion of the bolt to the safety leaf spring by means of flat steel bars. Figure 1 shows this principal schematically. The safety spring is much more accessible than the button itself.

In addition, the button has both linear and cross motions, while the spring moves only along the action. As you can see in the photos, another advantage of employing the spring is that Bar 2 can be held in place by this spring without any additional joints, which is critical for saving space. Another critical feature of this safety conversion is the slot in the top strip of the frame. It allows for a rigid positioning of Bar 1, the bottom of which is attached to the bolt, while the top slides in the slot.

It also provides the bed for Bar 2, and allows for a hingeless front joint between Bars 1 and 2. Finally, the rear end of Bar 2 is held in the slot by the leaf spring.

Figure 3. Figure 4. The result of this design is that the overall thickness of the whole device is equal to the thickness of the steel bars themselves, which is a mere 0.031 inch. Preparation of the Bolt There is a certain variation in shape of the bolt-tail on different Browning Superposed guns. However, there is not enough material on any of them to install Bar 1. Figure 2-A shows the bolt a with portion of metal removed for placing the small block. Figure 2-B shows the block brazed into this space.

Please note that this treatment of the bolt does not diminish the reliability of this part, since only a front part of it is actually locking the barrels and accepts the punch during the shot. Figure 5. Figure 6. The block should be reshaped, slotted for Bar 1, and drilled for roll pins as shown in Figure 2-C and 2-D. The small holes (f) are for the roll pins holding Bar 1. In Figure 2-C, you can see arched recesses on the sides of the block.

These are needed for clearance space for the mainsprings when the hammers are cocked (see Figure 9). The best way to drill holes f is before removing metal for the arcs. During drilling, Bar 1 should be inserted into the slot and fixed in the correct position. The most practical method is to drill one hole through the block with the bar inserted, install the roll pin, and then drill another hole. The Bars The bars (Figure 3) are made with Starrett’s 1/32-inch oil-hardening steel.

After shaping, they’re hardened and tempered to a spring-like hardness. Bar 1 has two teeth. Tooth A serves two purposes. First, it pushes Bar 2 backward and puts the safety on; and second, this tooth is plunged into the slot for stabilizing the bar’s movement. Tooth Bpulls Bar 2 to its initial position with the bolt going forward. This also clears the way for the safety button to be moved forward.

Note that Bar 2 does not have any attachment to the frame—other than sitting in the slot between Bar 1 and the safety spring. There is a certain freedom in shaping Bar 1, but my choice is to "swanneck" the bar in order to avoid contact with the sears. Figure 4 shows Bar 1 and the sears installed in the action without the hammers and springs.

Figure 7. The Frame Slot The slot in the top strip is the only modification of the original frame. Figure 5 shows how the slot can be cut. The best results can be obtained by cutting the slot with a milling machine. For this purpose, the frame should be secured horizontally in the vise, the stone or T-cutter installed in the chuck, and adjusted in height so that it is right between sears. Once the frame is secured in this manner, a slow feed will do the job.

Figure 6 shows the slot with hammers and safety spring installed. Final Assembly After preparation of the block, brazing to the bolt, cutting the slot, and shaping the bars, everything is ready for installing this conversion. First, Bar 2 should be put into the slot, then Bar 1 installed so that it engages Bar 2 with its teeth, and sits in both the top and bottom slots. At this time, two roll pins should be installed for rigidly attaching Bar 1 to the bolt.

Next, the safety button and safety spring are put into place. This step is shown in Figure 7. It’s important to prepare all parts so that there is no linear looseness in Figure 8. the joints. Otherwise, the movement of the bolt would not be sufficient for moving the safety button back far enough. Figure 8 shows the rear part of Bar 2 with the sears and spring installed. Note the tight contact between Bar 2 and the spring. Finally, Figure 9 shows the whole assembly with the hammers cocked.

Conclusions Nowadays, automatic safeties are considered to be the standard for hunting firearms. This has encouraged many hunters to look for a conversion of a manual safety to automatic on such guns as the Browning Superposed, Miroku’s Charles Daly, and others that were originally designed with a manual safety only. This conversion is quite simple in principle, and requires making only three small parts.

It also requires minimal changes to the original parts, thus making it possible to remove the new parts at a later date and return the gun to its original condition. Figure 9. As outlined here, this manual-to-automatic safety conversion has proven to operate reliably on several guns. Care must be exercised during the final adjustment of the parts to a particular action, especially to eliminate any looseness in the three joints.

If the safety button does not travel all the way back, the fault will usually be found in sloppiness in one or more of the joints. ■

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