Actually, progressive-depth rifling became standard with the shorter Pattern 1858 two-band musket and thereafter. The rifling twist was also changed from the earlier 1:78 to 1:48, which combined with the rifling change helped contribute to the 1858's reputation for accuracy.
If you can find a Parker Hale 1858 that you can afford, they are hard to beat. By the time you buy a Pedersoli and spend $500 for a new barrel, you may well find a Parker Hale for less.
If you can find a Parker Hale 1858 that you can afford, they are hard to beat. By the time you buy a Pedersoli and spend $500 for a new barrel, you may well find a Parker Hale for less.