Perhaps, but that was also before semi-automatic weapons were common. Can you imagine if they outlawed bullets in homes in a city in the United States?
Would you consider such a regulation reasonable? absolutely not.
I think it is safe to argue that it effects a gun regulation, whether that was the purpose or not. What else would they use gunpowder for in a city? The banning of gun powder in buildings is in effect a gun ban.
I believe it meets the qualification of being a pre-19th century firearm restriction.
Where exactly in the law shown do you find a prohibition on the possession of gun powder in the home? The law as written clearly only prohibits the gunpowder when it is actually in the weapon. It states nothing about prohibiting the storage of a cask of powder, or the storage of full powder horns. It simply prohibits weapons with a charge of powder in them from being in the buildings.
Here is the transposed text for those having difficulty reading the original. Another thing of note is the date that this was passed. It was passed 5 Years, 6 Months, and 3 Days BEFORE the ratification of the Bill of Rights, and 2 Years, 9 Months BEFORE the ratification of the U.S. Constitution.
There was no 2nd Amendment at the time
This act passed June 12, 1786
An Act in addition to the several Acts already made for the prudent Storage of Gun-Powder within the Town of Boston.
Whereas the depositing of loaded arms in the houses of the town of Boston, is dangerous to the lives of those who are disposed to exert themselves when a fire happens to break out in the said town:
1. Be it enacted by the Senate and House of Representatives, in General Court assembled, and by the authority of the same, That if any person shall take into any dwelling-house, stable, barn, out-house, ware-house, store, shop, or other building, within the town of Boston, any cannon, swivel, mortar, howitzer, or cohorn, or fire-arm, loaded with, or having gun-powder in the same, or shall receive into any dwelling-house, stable, barn, out-house, ware-house, store, shop, or other building, within the town, any bomb, grenade, or other iron shell, charged with, or having gun-powder in the same, such person shall forfeit and pay the sum of ten pounds, to be recovered at the suit of the firewards of the said town, in an action of debt, before any Court proper to try the same; one moiety thereof to the use of the said firewards, and the other moiety to the support of the poor of the town of Boston.
2. And be it further enacted by the authority aforesaid, That all cannon, swivels, mortars, cohorns, fire-arms, bombs, granades, and iron shells of any kind, that shall be found in any dwelling-house, stable, barn, out-house, ware-house, store, shop, or other building, charged with, or having in them any gun-powder shall be liable to be seized by either of the firewards of the said town. And upon complaint made by the said firewards to the Court of Common Pleas, of such cannon, swivels, mortars, or howitzer, being so found, the Court shall proceed to try the merits of such complain by a jury, and if the jury shall find such complain supported, such cannon, swivel, mortar, or howitzer shall be adjudged forfeit, and be sold at public auction; and one half of the proceeds thereof shall be disposed of the firewards, and the other half to the use of the poor of the town of Boston. And when any fire-arms, or any bomb, granade, or other shell be found in any house, out-house, barn, stable, store, ware-house, shop, or other building so charged, or having gun-powder in the same, the same shall be liable to be seized in manner aforesaid; and on complaint thereof, made and supported before a Justice of the Peace, shall be sold and disposed of as is above provided for cannon.