Not so sure the faster twists are just something one can make work. As
@Grenadier1758 stated, many original Jaegers had what we would call fast twist with their one twist per barrel length guns that were made and used for roundballs with their deeper grooves.
Out of curiosity a while back, I made note of the twist rates of original Jaegers in Shumway’s Jaeger Rifles book (actually a collection of his articles from Muzzle Blasts), and found he only commented on actual twist rates on six of the guns, though he mentioned many of the others were rifled. Now I may have missed a few, and I’m not going back to check right now (many have the book, so please check if you want to), but of the six with stated twists, two were call straight rifling, others 1-27, 1-28, 1-32 and 1-34. Appears the builders of these original guns didn’t know what they were doing with regards to twist rate? Or did they?
I had the opportunity to shoot some original shorter barreled (30” +/-) faster twist (approximately one twist per barrel length) guns while in Germany and Austria. They were using heavier charges of a powder finer than what the experts recommend under a patched roundball in their relativity deep rifled bores and accuracy was beyond impressive. They would hold their own against any contemporary built gun with slow (or fast twist), and likely out perform many from what I witnessed.
