Hi, this is a photo (screen shot) of a spreadsheet results of ballistic testing Swiss powder. It is a significant test that requires more explanation to appreciate the results:
In August 2013 I conducted velocity tests of 3f Swiss Powder using a Pietta 8" barrel 1858 Remington. Six cylinders were loaded with different weights of 3f Swiss Black Powder and 0.454" 141gr Hornady swaged ball. Powder weights (not volume) of 10,15,20,25,30, and 35grs were tested. Each cylinder was loaded with Swiss powder, followed by a 0.030" thick .45 Colt fiber wad, followed by a 1/8" thick Sagebrush lubed wad, followed by the 141gr Hornady 0.454" ball. The ball, wads and powder were compressed using the Tower of Power loading stand. No filler was used. A Chrony chronograph was used to measure velocity. CCI #10 caps were used. Each cylinder (six shots) were fired and the muzzle velocity measured. The results:
10gr 528.33 fps 25.90 SD 87.38 f-lb
15gr 679.63 fps 15.56 SD 144.58 f-lb
20gr 806.27 fps 17.06 SD 203.48 f-lb
25gr 909.46 fps 11.33 SD 258.90 f-lb
30gr 997.98 fps 18.91 SD 311.76 f-lb
35gr 1076.2 fps 6.83 SD 362.54 f-lb
Some things to note: The 35gr loading was a maximum load, the ball was almost flush with the face of the cylinder. The ball energy at maximum load is consistent with a 230gr .45 ACP. All the weights given are actual powder weight measured by an accurate electronic reloading scale. The reason I used actual weight instead of volume is for weight accuracy for the low weight charges. You can convert the weight to volume if you choose by using the actual weight of Swiss thrown by a 30gr volume measure:
Swiss Black Powder 3f - 24.4gr
Of special interest to me was the efficiency of Swiss powder with different loadings. I created a chart of muzzle energy as a function of powder weight, see chart:
Isn't that beautiful, the muzzle energy is almost linearly directly proportional to the powder weight. It should be noted that from previous velocity testing the new GOEX Olde Eynsford will perform almost identical to Swiss black powder, weight for weight.
If you extrapolate the muzzle energy chart to zero, the intercept is ~2.5gr of Swiss powder. That suggests that ~2.5gr of powder is required to overcome the friction of the ball in the bore.
Therefore a minimum powder loading for an 8" 1858 Remington is ~2.5gr of Swiss. Anything less and the ball will get stuck in the bore.
Regards,
Richard
