Written by Neil Harmse
Chapter 18. The Slug Gun
As I approached my mid-60s, I decided I would ‘retire’ from game hunting and concentrate on wingshooting. I have a passion for vintage and well-made side-by-side shotguns, and it gives me great pleasure to step into the veld with a gun that is over 100 years old and still shoots as well today as it did when it left the gun-maker’s bench.
This is the epitome of the gun-maker’s art. I sold my hunting rifles and kept a selection of favourite shotguns with which to pursue my chosen sport.

Winchester Model 37 slug gun after restoration.
In the areas where most of my wingshooting takes place, I often come across warthog and feral pigs which do a lot of damage to farmers’ crops, causing a loss of income for the landowner.
This sparked an interest in me to hunt these problem animals, but I had no gun appropriate for the task. Carrying a few rifled slug loads in a pocket while hunting birds was not an ideal solution, as these are not at all accurate in my vintage side-by-side shotguns and could be damaging to them. My thoughts turned to a dedicated slug gun.
During a visit to the Krugersdorp workshop of my good friend and gunsmith, Hennie Mulder, I mentioned that I was looking for an old single-barrel 12-bore shotgun such as a Harrington and Richardson, Stevens, Savage or similar to convert to a slug gun as a project.
I noticed a faraway look in Hennie’s eyes as he walked over to one of his storage safes. Scratching around in the deepest recesses, he produced an old, very rusty Winchester model 37 which he had taken into stock many years ago. He offered this old gun to me, saying that if it would serve the purpose, I could work on it in his workshop and he would help where he could.
Despite the exterior rusty and neglected look, the gun was in sound shooting condition. On dismantling it, we found a lot of rust and surface pitting on the outside of the barrel and action, but Hennie assured me that this could all be cleaned up. So a project was born.
The first order of business was for me to polish out the barrel with ISSO bore paste, bore solvent and a piece of ‘Scotch’ pad using a long rod and a drill. With a bit of hard work and elbow grease, the barrel was soon shining again, with extraordinarily few signs of pitting, and appeared to be in quite reasonable condition. Next was using the lathe to cut the 32” (81,28cm) barrel down to a manageable 25” (63,5cm) and carefully crown and polish the muzzle. This also served to remove the extra-full choke and turn it into a cylinder choke, which is ideal for optimum slug accuracy.


Left: Restoration of the Winchester.
Above: The Winchester model 37 before restoration.
Right: Working on the stock.

I had decided to fit a ghost-ring sight which would be tter for my tired old eyes, so I searched for through my boxes of old Magnum magazines and found some articles by Gregor Woods and Koos Barnard covering their ideas and experiences with these sights. I started cutting them out and filing them, and I soon had a couple of prototypes to try out. Hennie had a low-profile, front-sight ramp and bead sight which would serve nicely, but the ghost ring rear-sights I had made were not quite suitable. Scratching among some spares in Hennie’s storage trays, I found a sling swivel ring that I thought would make an ideal sight. At around 4mm, the aperture looked right and if we could find or make a base to mount it on, it would be ideal. Also among the spares, I found a sight base that someone had cut down, which could be adapted. The biggest problem was cutting the radii of the front- and rear-sight bases to match those of the barrel round where the mounting points would be. This was where Hennie’s expertise came to the fore. He carefully worked these down on a lathe until the fit was perfect. He then fixed these onto the barrel with Superglue as a temporary measure until we could bore-sight and test-shoot the gun.
The stock was a bit short and needed lengthening, so I added a recoil pad to bring the length of pull up to my required 14½” (36,8cm). Once this was done, I tackled the stripping and sanding of the stock and fore end, which took a lot of elbow grease. I then started filling, sealing and oiling to bring out the grain and give it a durable finish. I used Birchwood Casey’s True Oil, which I rubbed into the stock in very thin coatings, leaving it to dry and set for a day between applications. This was done over a period of about a week. Once I was happy with the seal and finish, I hand-rubbed a mixture of Schaftol and walnut oil into the wood, repeating it several times. I then polished it with a piece of oiled sheepskin. This took days of hard work, but the wood turned out looking good. Well worth the effort.
Hennie again came to the rescue with his expertise, doing a wrap-around checkering pattern at about 18 lines per inch to provide a good grip, since we figured the lightweight gun would produce a sharp recoil with slug loads. Before polishing and re-blueing, we went to the range to carry out a rough bore-sight and preliminary firing to ensure the sights were correctly positioned before soldering them into place. Hot Power Guns in Krugersdorp has a convenient indoor range that allowed us to test-fire at 25m, which we felt would give an indication of where the shots were going. We used SP Brenneke slugs, as well as African Rifled Slugs loaded with Borra slugs from Italy. These were remarkably similar to the old SP Penetrator slugs. These slugs produced a three-shot group measuring 3,5cm x 5cm. This was the first time I had used a ghost- ring sight and I was impressed with the quick target acquisition it facilitated.
The next and most time-consuming task was removing the rust and grime from the outer barrel, action, interior and flats, as well as all the other nooks and crannies, and then preparing the metalwork for blueing. Fortunately, Hennie offered the help of his able assistant, Sam, who did most of this work. Among his other areas of expertise, Sam was excellent at preparing the metalwork for the bluing tank, so I left this in his capable hands.
When the metalwork was done to satisfaction, Hennie applied his special rust-blueing formula which he used for his custom rifles and shotguns. This produces a deep, rich and durable gun-blue finish to the metalwork which protects it from rust and corrosion.
Well, finally, the hard work and the long wait paid off. The old gun, which had spent years in the back of Hennie’s gun safe rusting away, now had a new lease on life and had been 96 transformed from a dirty, rusty old ‘sow’s ear’ into a functional, good-looking and working ‘silk purse’, which can once again be taken with pride into the hunting field.
My grateful thanks go to Sam, whose draw filing and polishing of the metal to remove the rust and pitting brought it almost to a mirror finish, ready for the bluing tank. Without his hard work, the finish would not have turned out as well as it did. And, of course, my special thanks go to Hennie Mulder for his expert advice and help in achieving the final result of this interesting project.
All that is left now is to arrange a pig-hunt for the ultimate test!
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