A collection of French pocket pistols

[urbanspaceman]

Thank-you. I don't speak French so here is what Google makes of the less obvious or previously established bits.
Inventor of a new way of placing the plate of a rifle which makes it capable of being removed and put back in place in an instant. Approved by the academy 1772 and 1774.
He demonstrates that short rifles carry an equal load, further than long ones and is obliged to collect the lead from those which are separated by an operation simple which is particular to it.
Anyone make any sense of it?