How can PSI be converted to a recognizable or commonly used force? Answered

If you mean lb/in^{2 you could convert it to other forms using these formulas}
psi x 144 = lb/foot²
psi x 0.068045964 = atmospheres
psi x 703.06958 = Kg/m²
psi x 6,894.7573 = pascals
psi x 5.1714932 = cm of Hg
psi x 2.0360207 = in of Hg
psi x 0.068947573= bars

I cant thick of any others and if you need to go back words then replace the = with / and the x with = and work from right to left

Is this some kind of pneumatic gun?
You need to run some ballistic tests, how about this one?
https://www.instructables.com/id/how_to_measure_the_FPS_of_an_airsoft_knex_or_oth/

L

F/m) to arrive at velocity (v = vo+at).