I suspect those same gunmakers would have been perfectly happy to make muskets...if they could get the parts they needed and if they got paid for their work...both of which were highly questionable.
Maybe not perfectly happy.
Their reluctance stemmed from finances: the Lancaster gunsmiths claimed initially that they could not make the muskets at the prices mandated by Philadelphia authorities. They stated that they "could not make them for the Price of £4.5.0 nor would be governed by the Philadelphia price. Nor would make them for less than Five pounds." Is is after this refusal that the Lancaster committee threatened the gunsmiths and each agreed that he would work only on muskets from November 1775 to March 1776, furnishing "as great a quantity of Muskets & Bayonets as he possibly can in that time at the Philadelphia prices agreeable to the Pattern." (But, as I mentioned, they didn't in fact give up making rifles.)
The gunsmiths would be "glad of an[y] excuse to lay by the Musket-Work & make Rifles," the Lancaster committee noted several months later, "
which are more profitable for them."
Obtaining barrels does not seem to have been a major problem.
There were barrel mills in Lancaster County, including one in operation by 1776 owned by Dickert and John Henry. Obtaining locks, as we've discussed here a few times in recent months, was where the supply chain failed the gunsmiths. It is interesting that, early on, the gunsmiths do not mention this as a reason why they should not be compelled to make muskets. Perhaps the scarcity of locks hadn't yet become evident.
Depriving them of their tools is idiotic. Who was going to use them?
The point was to deprive the gunsmiths of a way to make a living, if they did not comply. So more draconian than idiotic.