01/02/2023 | Hints from the experts
Cartridges for cowboy action shooting with RS14
The new RS14 from Nitrochemie Wimmis is a special powder with low bulk density and reduced energy content. It is also suitable for cartridges that were originally designed for black powder propellants – revolver and rifle cartridges with bulky cases (e.g. .45 Colt, .45-70 Government, etc.). These calibres are highly popular in cowboy action shooting, where there is a preference for loads with a low recoil.
These light loads are often achieved using a “traditional”, fast burning powder. The fact that only 30-50% of the useable case capacity is used means there are certain disadvantages. The low filling level means the shooting process is affected by the position of the powder inside the case. A double load is also possible – which would have catastrophic consequences for shooter and gun alike. The new RS14 is free from these disadvantages. The low bulk density and low energy content mean the filling level is always above 50%. Even a load with a 100% filling level (normally) remains below the permitted Pmax. A summary of the RS powders for handguns is provided in the table below:
| RS14 | RS12 | RS20 | RS24 | ||
|---|---|---|---|---|---|
| Bulk density Energy content (Qex) |
g/l J/g |
316 3208 |
616 4022 |
617 4098 |
825 4367 |
In 2022, the RS14 development process was completed, and the first test samples were issued to both sport shooters and ammunition manufacturers. The Old West Shooting Society Switzerland (OWSSS) also received a sample, and the society’s president and his colleagues put the new powder through its paces.
The new RS14 powder was tested in a number of different calibres and guns (revolvers, lever-action rifles). The clean combustion with light loads and the precision on the target were both impressive. Due to the lack of a gun chronograph, it was not possible to measure muzzle velocity during these tests. This measurement provides information about the uniformity of the load, and is also used for RS customer load data.
In order to determine the muzzle velocities, the president of the OWSSS was invited to come and shoot in Wimmis in November 2022. The tests were not performed on the Nitrochemie premises, but instead at the pistol shooting range in Wimmis. We would like to say a huge thank you to the Shooting Range Officer, Mr. Lehnherr, who assisted us during the tests and made the facility available to us. The muzzle velocity was measured by Jan Krcmar (RS team at Nitrochemie), using a LabRadar.
The measured velocities and associated QuickLOAD calculation are shown in the tables below (SD = standard deviation, diff. = difference between the measurement and the QuickLOAD calculation). For the sake of precision, the loads that were used were weighed individually.
Gun: Uberti 1873 Cattleman revolver
- Barrel length: 5.5"
- Calibre: .45 Long Colt
- Case: Starline
- Bullet: 260 gr lead bullet with plastic coating (bullet length 16.6 mm)
- Cartridge length: 39.9 mm
- Crimp LEE Factory Crimp
- Primer: LP Murom
| Load gr |
Number | V0 m/s |
V0 min m/s |
V0 max m/s |
Extreme spread m/s |
SD m/s |
E0 J |
|---|---|---|---|---|---|---|---|
| 7.0 | 10 | 226 | 217 | 232 | 15 | 4.1 | 430 |
| 6.5 | 10 | 221 | 217 | 226 | 9 | 3.0 | 411 |
| 6.0 | 10 | 212 | 207 | 218 | 11 | 3.1 | 379 |
| 5.5 | 10 | 206 | 202 | 214 | 12 | 4.0 | 357 |
QuickLOAD calculation
| Load gr |
Filling level % |
V0 m/s |
Diff. m/s |
Pmax bar |
|---|---|---|---|---|
| 7.0 | 80 | 225 | 1 | 675 |
| 6.5 | 74 | 213 | 8 | 592 |
| 6.0 | 68 | 201 | 11 | 515 |
| 5.5 | 63 | 188 | 18 | 445 |
Summary: .45 Colt in the revolver
- Very good V0 extreme spread.
- Fired cases are clean, no powder residue.
- QuickLOAD calculation matches the measurement well.
Gun: Uberti Winchester 1873 lever-action rifle
- Barrel length: 20"
- Calibre: .45 Long Colt
- Case: Starline
- Bullet: H&N RN .452, 230 gr HS (round nose 1.5 mm flattened -> flat nose)
- Cartridge length: 40.0 mm
- Crimp LEE Factory Crimp
- Primer: LP CCI 300
| Load gr |
Number | V0 m/s |
V0 min m/s |
V0 max m/s |
Extreme spread m/s |
SD m/s |
E0 J |
|---|---|---|---|---|---|---|---|
| 5.3 | 10 | 212 | 202 | 219 | 17 | 6.0 | 335 |
QuickLOAD calculation
| Load gr |
Filling level % |
V0 m/s |
Diff. m/s |
Pmax bar |
|---|---|---|---|---|
| 5.3 | 54 | 247 | -35 | 347 |
Summary: .45 Colt in the lever-action rifle
- Good V0 extreme spread.
- Fired cases are clean, no powder residue. Nevertheless, a higher load is recommended (from 6 gr).
- QuickLOAD calculation (V0) is higher than the measurement (the load is very low, so the bullet can be slowed down while it is still in the barrel).
Gun: Winchester 1892 lever-action rifle (original from 1914)
- Barrel length: 20"
- Calibre: .44-40 Winchester (.44 WCF)
- Case: CBC
- Bullet: 200 gr lead bullet (LEE mould, dia. 429 -200-RF calibrated to .427)
- Cartridge length: 39.3 mm
- Crimp LEE Factory Crimp
- Primer: LP Winchester
| Load gr |
Number | V0 m/s |
V0 min m/s |
V0 max m/s |
Extreme spread m/s |
SD m/s |
E0 J |
|---|---|---|---|---|---|---|---|
| 7.0 | 10 | 321 | 311 | 326 | 15 | 4.0 | 668 |
| 6.5 | 10 | 312 | 307 | 314 | 7 | 2.6 | 631 |
| 6.0 | 10 | 296 | 292 | 299 | 7 | 2.1 | 568 |
| 5.5 | 10 | 277 | 236 | 295 | 59 | 16.3 | 497 |
QuickLOAD calculation
| Loag gr |
Filling level % |
V0 m/s |
Diff. m/s |
Pmax bar |
|---|---|---|---|---|
| 7.0 | 83 | 322 | -1 | 672 |
| 6.5 | 77 | 307 | 5 | 588 |
| 6.0 | 71 | 293 | 3 | 511 |
| 5.5 | 65 | 277 | 0 | 441 |
Summary: .44-40 Winchester
- Very good V0 extreme spread from the 6.0 gr load upwards (5.5 gr load is too low).
- Fired cases are clean (apart from the 5.5 gr load), no powder residue.
- QuickLOAD calculation matches the measurement very well.
Gun: Miroku Winchester 1886 lever-action rifle
- Barrel length: 26"
- Calibre: .45-70 Government
- Case: Starline
- Bullet: H&N TC 400 gr HS
- Cartridge length: 63.9 mm
- Crimp: Roll crimp
- Primer: LR Murom KYB-7
| Load gr | Number | V0 m/s |
V0 min m/s |
V0 max m/s |
Extreme spread m/s |
SD m/s |
E0 J |
|---|---|---|---|---|---|---|---|
| 13.5 | 4 | 315 | 313 | 317 | 4 | 1.4 | 1286 |
| 15.6 | 5 | 342 | 335 | 348 | 13 | 5.3 | 1516 |
QuickLOAD calculation
| Load gr |
Filling level % |
V0 m/s |
Diff. m/s |
Pmax bar |
|---|---|---|---|---|
| 13.5 | 78 | 321 | -6 | 1258 |
| 15.6 | 90 | 347 | -5 | 1576 |
Summary: .45-70
- Very good V0 extreme spread.
- Fired cases are clean, no powder residue.
- QuickLOAD calculation matches the measurement very well.
Gun: Uberti 1873 Cattleman revolver
- Barrel length: 4.75"
- Calibre: .357 Magnum
- Case: PPU
- Bullet: H&N RN 158 gr HS (1.5 mm round nose, flattened -> flat nose)
- Cartridge length: 39.6 mm
- Crimp: Roll crimp
- Primer: SP Ginex SP
| Load gr |
Number | V0 m/s |
V0 min m/s |
V0 max m/s |
Extreme spread m/s |
SD m/s |
E0 J |
|---|---|---|---|---|---|---|---|
| 4.0 | 10 | 207 | 195 | 222 | 27 | 8.6 | 219 |
QuickLOAD calculation
| Load gr |
Filling level % |
V0 m/s |
Diff. m/s |
Pmax bar |
|---|---|---|---|---|
| 4.0 | 79 | 208 | -1 | 624 |
Summary: .357 Magnum
- V0extreme spread only satisfactory. Note: The 4 gr RS14 load was also shot in other guns (and with other bullets), and the extreme spread was better.
- Fired cases are clean, no powder residue.
- QuickLOAD calculation matches the measurement very well.
Summary: Cowboy action shooting with RS14 cartridges
- In general, there is a very good V0 difference, provided the load is not too low.
- Although loads with a filling level of around 50 - 100% are possible, the best V0 extreme spread is (normally) achieved when the filling level is approximately 70 - 90%.
- Fired cases are clean and there was no powder residue in the cases or the guns.
- Charging in the powder device works well.
- QuickLOAD calculations compared to the V0 measurements are in the good range.
Jan Krcmar
RS enthusiast