They argue gain twist even today but if one was better you'd be able to prove it, so as Robins said in 1746 there isn't a difference and at the time they only used gain twist on small pistols. I need a copy of Robins book "new Principles of gunnery" They discussed twist of different shaped bullets in muzzle loaders and breech loaders. I still think that the fast twist in some Jaegers is due to the fact they may have been shooting conicals.
That's what I was saying I think any benefit of the gain-twist rifling was mostly realized with conicals. I also agree however that conicals were more common earlier than a lot of folks tend to believe.
And again ... same goes for percussion ignition. I think percussions were gaining in popularity faster and sooner than what seems to be traditionally believed. I cannot wholeheartedly agree with the theory that only flintlocks were used at the Alamo. 
Percussion guns swept the flintlock away in England rapidly. IN SHOTGUNS.
Rifles converted much slower according to Nigel George in "English Guns and Rifles".
Some of us that have spent time considering it think that the early percussion systems and/or caps were likely less consistent. This was not a significant factor in shotguns where the faster ignition greatly aided WING SHOOTING. The "sporting" idle rich/royalty/landed gentry who did most if not all the wing shooting wasted no time either buying new percussion guns or converting their flint guns. But inconsistent ignition will wreck havoc on rifle accuracy and this could be the reason rifles lagged somewhat.
But this is supposition. However, today "magnum" caps cause accuracy problems with BP loads. Great with grey powders.
But we have flintlock rifles in widespread use and still in production in 1840s American. Sure people were using percussion rifles & guns and some adopted it early. But we have documents that indicate that in the WEST the flint rifle hung on. It was proven technology.
Even though there were hardware stores stocking percussion caps by the millions in the mid-late 1830s the fur companies were still ordering flintlock rifles.
We have patent dates for percussion ignition and a host of guns with various early percussion ignition systems that are pretty well dated. Many English guns were serial numbered and can be dated by this in some cases.
There were so many breech loading flintlocks in England in the 1750s and before that were virtually identical to the Ferguson that some have wondered what Ferguson invented. (IIRC it was notches in the threads of the rotating breech piece to reduce powder fouling jamming the screw). But these, including the Ferguson, shot ROUND BALLS from all accounts.
The "conical" is not well documented until the advent of the picket bullet and as previously stated the picket requires more complex equipment to shoot accurately. Reminds me, there is a Picket Rifle match on the 4th of June, I need to swage some more bullets and cut some patches. They have to be round and just the right size to work right with the starter.
It was circa 1850 before the military, despite considerable experimentation starting in the early 19th century, SFAIK, perfected the minie ball for infantry use. Naked bullets, as previously stated, are essentially useless for anything but military and target use. General civilian use of either is not very common. Pickets WERE common by the 1830s-40s, the bullets Colt Perc, revolvers shot were very much like a pointed picket bullet. But picket rifles INVARIABLY are made to accept a starter or false Muzzle. Without one or the other of these the picket just does not work. This is evident in writings of the time and current experience.
With all the cased sets of various sorts of firearms in England and elsewhere there would be some elongated bullets or moulds showing up if conicals were in use in the 18th century. The field of firearms has a great wealth of surviving firearms from the 18th century, both here and in Europe.
Folks really need to do more RESEARCH and less supposition.
Don't matter how much you want something. In the realm of history no proof means its did not exist. Its not as though some time traveler went back to the Battle of Breeds Hill with several gallons of maxi-balls, a box full of TC "Hawkens", 100000 caps, 100 pounds of Pyrodex and started a revolution in ballistics.
No elongated bullets in the written or archeological record, no surviving moulds or bullets in cased sets and so no proof.
Conclusion? No "conicals" IN USE before 1820 until proof surfaces to the contrary.
Dan
