27.05.2024 | Hints from the experts

RS12 powder for 12 gauge Tungsten Super Shot, or the search for alternatives to lead shot with powder from Reload Swiss

1. Introduction

Over recent years, several Swiss Cantons have introduced regulations to restrict the use of ammunition that contains lead.

Although perfectly suitable and equally effective alternative ammunition is available for standard rifle calibres, the situation is more difficult when it comes to (lead) shot. The substitute shotgun shells currently available on the market do not necessarily exhibit the same effectiveness (see next chapter), are very expensive and/or require a shotgun designed for a higher pressure.

One way to avoid these disadvantages is to reload your own cartridges.

This article does not focus on the techniques and materials needed for reloading shotgun cartridges, as there is already plenty of information hereto available on the internet.

Instead, this article looks at the use of an effective alternative that European manufacturers are unable to use at this time, and further provides recipes using a propellant from Reload Swiss. There are unfortunately very few guides for using the latter in cartridges in shotgun gauges as for now.


2. The various alternatives and Tungsten Super Shot

There are currently various alternatives to lead shot (which has a density of approximately 11.5 g/cm3). There are advantages and disadvantages to all of them, which we will attempt to set out below, although we can’t claim to provide an exhaustive list:

  • Steel (in reality soft iron) has a lower density (7.8 g/cm3), meaning that a larger diameter is needed to achieve the same penetrating power. In general, it is advisable to adjust the shot number by two to four compared to lead in order to get a larger diameter.
    As the density of the metal is lower, the initial velocity needs to be increased to ensure there is still adequate velocity when the shot hits the target. Given that the diameter of the individual pellets is larger, a bigger shot load is also needed to make sure that there is approximately the same number of pellets. This requires guns that are designed for higher pressures. Hunters talk about “steel-proofed” shotgun barrels. Ultimately, these are primarily shotguns that can withstand pressures of 1,320 bar (900 bar is the usual pressure) and practically always have a chamber length of 76 mm or more, so that heavier loads can be fired with an adequate number of pellets.
  • Bismuth and copper: I’m afraid I’m going to have to disappoint those of you who are interested in these alternatives. I don’t know enough about these alloys and haven’t looked into them any further, as I can’t really see any derived genuine improvement on lead. Their penetrating power is similar to that of steel shot. However, one advantage is the option to use them with a felt wad, which is not possible with the other alternatives.
  • SpheroTungsten is an alloy with a density of 12 g/cm3, which is similar to that of lead. However, due to the hardness of the material, the pellets will not deform, which means the shot maintains its velocity better in the air.
  • Tungsten Shot (TS) has a density of 15 g/cm3, meaning it differs more significantly from lead and has a higher penetrating power. Due to its hardness, it offers the same ballistic advantages as the preceding alloy.
  • Tungsten Super Shot (TSS) is a genuine improvement on lead. Everyone was very happy with its performance during testing. Its density of 18 g/cm3 significantly increases its penetrating power. Due to its hardness, it doesn’t deform, and its high density ensures that it maintains its velocity in air better than any other material. However, as with steel and all pellets made of Tungsten alloys, it is essential to use “steel” wads, i.e. specially adapted wads that protect the barrel the whole time the shot is travelling through it.
    Moreover, the hardness of this material currently exceeds the specifications of the European C.I.P. standard. This standard sets out strict load specifications for manufacturers (hardness of the pellets, ratio between velocity and weight of load, velocity and pressure).
    As TSS exceeds the hardness standard, the only feasible solution is to load your own ammunition.

3. Some comparisons

To compare density, I filled one “Baschieri & Pellagri Steel” wad (intended for use with 28 g of steel) with lead, and another with TSS in the same diameter. The result was that it worked well with 28 g of steel, 43 g of lead and 68 g of TSS.

The website www.i-shoot-tss.com has a lot of very interesting information and advice on the subject of TSS. For example, it includes tables that compare the penetrating power of various materials. These show that a 3.75 mm steel pellet at 40 m has the same penetrating power as a 2.75 mm lead pellet or a 1.99 mm TSS pellet. At this distance, TSS in this diameter will kill a mallard.

If you are interested in making your own shotgun shells for roe deer hunting and usually use lead with a diameter of 4 mm or 4.5 mm, then 2.75 mm or 3 mm TSS pellets would absolutely be suitable, just as good or even better.

We are not going to look into the benefits of TSS for shots from longer ranges. In general, the Swiss regulations that govern the use of shot permit a maximum range of 40 m. However, given the properties of TSS, it would be possible to manufacture shot that would be lethal from much longer distances. Duck hunters in the USA know that very well, as they use TSS primarily because of its superior properties. The owner of www.i-shoot-tss.com is also well aware of this, since the website sells everything needed to make TSS shotgun shells (apart from the powder).

Our team bought TSS through this website and can nothing but to recommend it. The customer service is excellent and the products were delivered on time and as according to the agreed conditions.


4. RS12 for 12 gauge

Unlike Vectan, Reload Swiss (RS) seems to have little experience with using its propellant for reloading hunting shotgun shells. The company provides a number of recipes for customers, which can be found on its website, in the “Tips & Tricks” section. However, these recipes are designed for loads of over 30 g using lead and do not necessarily meet the relevant requirements when using TSS. We therefore decided to take these sparse recommendations as a starting point and, without taking any risks, carry out a large number of tests to find suitable recipes for TSS shot loads of 24 g, 28 g and 32 g.

Before you try reloading, you should ensure you have fully mastered all the necessary techniques. The author of this article accepts no liability for any mistakes on your part.


The table below sets out the results:

Shot load in grams

RS12 in grams

Average V0


Extreme spread between pellets

Standard deviation














































We did not test the pressures of these different loads. The utmost caution is advised, particularly if your shotgun is old.

Reload Swiss offers recipes using 1.82 g and 1.88 g of RS12 with a 32 g lead load. It turned out that these loads were far too powerful for the materials we used. We achieved a V0 of 460 m/s with 1.82 g, while the company indicates 390 m/s. The plastic of the cartridge stuck in the chamber, while the cap was ejected. We therefore reduced the load to avoid risks. Exercise caution. If you don’t have a chronograph and you have an old shotgun, use our low reference values with 1.52 g of powder.


5. Materials used to make the cartridges



Brand/model: Fiocchi 616
Note: /


Brand/model: Baschieri & Pellagri Steel 28 g
Note: Slit four times to the bottom


Brand/model: Siarm discs, reinforced 3 mm 20Ga
Note: 1 between powder and wad for more height (see picture of wad). 1 more in the wad, after the load


Brand/model: Siarm Diana Kal. 20 H12 mm
Note: 1 in the wad because TSS does not fill the full volume (1 x 12 mm disc and 1 x 3 mm disc for 24 g and 28 g of TSS. Only 1 x 12 mm disc for 32 g)


Brand/model: Recovered from ball trap range
Note: /

6. Experimenting with the grouping of the shot string

The tests were largely conducted with a half choke but, considering groupings, we also tested our TSS ammunition with a true cylinder choke.

To obtain values for comparison purposes, we tested ready-made ammunition, too.

We tested:       

  • The well-known Rottweil BB, an ammunition with 66 4.5 mm lead pellets that is used with a fibre wad.
  • The Xtrem 40 from Mary Arm, an ammunition with 96 SpheroTungsten pellets that is used with a steel wad. This ammunition has proven itself to be an excellent lead-free alternative for roe deer hunting.     
  • We tested our TSS ammunition as follows: With 3 mm, 2 mm, 24 g, 28 g, 32 g, wad slit four times either to the bottom or half way down, either pressed or not, wad slit eight times or not slit at all.  
  • Only results that are relevant for hunting roe deer with a shotgun are shown. These are also the tests we carried out most often:

90 x shot pellets in an approximately 40 cm circle with half choke at a distance of 30 m.


66 x lead pellets in a 60 cm circle with half choke at a distance of 30 m.


TSS 24 g 91 x 3 mm pellets in a 40 cm circle with half choke at a distance of 30 m.


TSS 24 g 91 x 3 mm pellets in a 50 cm circle with true cylinder choke at a distance of 30 m.

The way that the wad was slit had a major influence on the spread of the string. It must be slit four times, to the bottom, and the four sections must be pushed apart. In short, the wad must be pre-shaped so that, when opening up as it leaves the barrel, it enables the string to achieve the best possible spread.

The shape of the string doesn’t change at impact, regardless of the diameter of the pellets and the weight of the load. If the load contains more pellets then there are simply more pellets in the target – the width is the same. This means that the length of the string must be different.

V0 velocity also seems to have no influence on the shape of the string.

Choke also has a positive impact on the string. When hunting roe deer at a maximum range of 40 m, a true cylinder choke combined with a quarter or half choke is suitable. The true cylinder choke allows for a better distribution of the pellets over a slightly larger diameter.

When comparing against the two types of ready-made ammunition, you can see that our results are similar to the Xtrem 40 from Mary Arm. That is logical. The wads tend to be better at keeping the string tight.

It is also evident that the spread with the Rottweil BB is already very wide at 30 m. Even when the aim is accurate, lead can reach the haunches, while also hitting the chest and head.


7. Number of pellets by load and diameter

TSS diameter

TSS load

Number of pellets

2 mm

24 g


2 mm

28 g


2 mm

32 g


3 mm

24 g


3 mm

28 g


3 mm

32 g



8. The first tests in the field

The ammunition was tested in the 23/24 season in roe deer and duck hunting. We used a powder load of 1.52 g for old shotguns and a load of 1.55 g for modern shotguns. However, there was ultimately no difference in terms of effectiveness.

TSS with 3 mm at 24 g proved to be astonishingly effective and clearly superior to lead for roe deer. It didn’t make sense to use loads of over 24 g, as they don’t offer any advantage at the legally permitted range of 40 m.

The game seems to be better preserved when the impact is “cleaner”. The fact that the TSS pellets are not deformed seems to play a big part in this.

The stopping power also seems to be very good, with all roe deer staying exactly where they were.

In terms of duck hunting, the effectiveness of lead is beyond comparison with steel. Ducks that are shot with lead pellets slump and seem to die in flight, this in contrast to steel, where a second shot is often needed, even though you can tell from the duck’s reaction that the first shot hit it.

It is difficult to say whether 2 mm pellets are better than 3 mm shot. Both diameters actually proved to be effective at a range of 40 m. The 24 g load was also sufficient, as loads of 28 g and 32 g were not seen to produce better results.


9. Price

As in the case of most innovations, it is not all benefits. The price of TSS is high, and the 24 g load comes to CHF 1.88. The cost of the powder and primer add a few more centimes to that.

It is therefore not the type of ammunition to use for training. However, hunters don’t generally shoot a large volume of cartridges. What counts most is lethality, and this is where TSS is superior to any other type of shot.


10. Conclusion

Reloading is increasingly falling out of fashion among shooters and hunters in Switzerland. This downward trend is probably due in part to lower costs as well as to the purchase of relatively cheap ready-made ammunition.

Nonetheless, making/preparing your own ammunition allows you to explore possibilities beyond the well-trodden paths that the standardised products of all manufacturers force shooters down to. Using TSS for shotgun shells is a good example of what can be achieved, primarily for special types of hunting such as hunting roe deer with a shotgun as practised in the French-speaking part of Switzerland.

We hope that the results presented here catch your interest and that reloading at home starts to pick up again in the next few years.

We are fortunate enough to have access to a Swiss-made propellant that is famed for its reliable quality, so let’s make the most of it.


Yves Bourguignon

The perfect hit!
© 2024 Reload Swiss