Not stating that I'm going hunting for 400 yards out.
Again just trying to learn what these are capable pf doing.
Been Hunting and shooting for over 50 years, I don't take a shot unless I know it's going to drop where I shot it, or pretty close by.
Dropping a deer in its tracks generally requires at shock to or interruption of the nervous system. Sir William Drummond Stewart reported that Mule Deer were harder to stop with his 20 bore rifle (a Manton IIRC) than an Elk. He also stated he killed more game with less lead than any rifle at Rendezvous. But he might not have been as hung over either. In my experience shot placement trumps caliber.
It takes an experienced ML shooter to kill past 120 yards with traditional ML of 50-54 caliber. And wind can be a serious drawback to this. I seldom shoot at game standing if I can avoid it. Caliber depends of the game hunted. 50 cal is near perfect for deer and will kill larger animals but for Elk, for example, I like something bigger. But few American traditional stock designs after 1790-1800 are good for bores over 54. Some of the early large buttplate rifles are good. A carry over from the large bore German rifles.
Twist? I suspect that an honest look at original American rifles will show them to be 48” and for “American” calibers this, all comments aside, is a good twist for a PRB. Daryl has proven that even a 69 caliber does not need a 72” twist if I recall the twist rate correctly. Still a round ball will stabilize and shoot very well at low rotational speeds. I have a 62 caliber barrel with a 48 twist that I should have tested for patch integrity before I cut 2 pistol barrels off it. But I got lazy…. The typical Kentucky generally had a “4 foot” barrel. Something in the 42” plus range. The Barnett, Wilson and Grice trade rifles imported for use by the British Indian allies during the Revolution had barrels in the 43-46” length and one turn in the barrel length according to DeWitt Bailey in “British Military Flintlock Rifles”.
I have a 30” 8 groove .67 caliber barrel, .008 deep, narrow lands. And it shows abrading of the patch at the lands but they do not fail. This is with 140gr of ff Swiss. The thing about larger RBs is they have a lot of rotational inertia so if twisted too fast with a high acceleration rate the patch may (will) fail. I think if this rifle .010-.012” grooves it would be better in regard to the patches as would a 10 or 12 groove. But I cannot imagine it being more accurate.
I have a 66” twist 54 Douglas that shot into 6” at 200 yards 5-6 shots with a peep sight shooting from a lawn chair and a pickup tailgate for a rest.
Remember that in testing by the British Army in Feb 1800 the Baker proved the most accurate at 300 yards. It had a twist close to 10 feet and was a .65 caliber in this case. There was a mistaken belief by some that the slower twist would give better velocity. Not sure this would stand a modern test. And Europe at least and in Britain in many cases it was thought proper to make the rifling 1 turn in the length of the barrel even after the Bakers adoption. This continued until the end of the ML rifle according to Forsythe in “The Sporting Rifle and Its Projectiles”. They even developed the 2 groove barrel and belted ball to allow heavier charges with the fast twist. The use of fast twists in “standard” rifling forms resulted in many hunters in Africa and India using smoothbores since they could not get rifle accuracy from a fast twist rifle (the rifles used generally had barrels under 30”) at the velocity for the needed penetration on large dangerous game. But in England they were generally loading charges more like that used in a shotgun and the fast twist was OK.
If I were going to shoot to 200 yards in a rest match I would want a tight ball fit and a good charge of powder. Larger balls 66-72, have a better BC and will buck the wind slightly better than a 54 would but they will all require a number of wind flags to make a good score. Even really large RB like a 4 bore will likely have a BC that starts with a .1 at best. And wind drift, from what I have read, is the result of the TIME the bullet loses going to the target compared to shooting it the same distance in a vacuum. And RBs balls lose a lot of time with an atmosphere.
