so here's how weapons are balanced in 2.2
first, we have the efficiency formula of 50000+(1000*mass). mass is the weight of the weapon.
This formula determines the weight-efficiency creep of weapons [i.e., why heavier weapons have better dp/hp to kg than lighter weapons]. Heavier weapons have a higher number, and thus higher efficiency. a 7kg razor has 57000, a 70kg sledgehammer has 120000.
DP and HP is extracted from the result of the previous formula via Efficiency=DP*HP/mass, and is adjusted within a range of +/-40% 1:1 with each other. for example, a razor's base formula is 57000=285dp*1400hp/7kg. after adjustments it ends up as 399dp and 1000hp (a dp/hp ratio of 1.4 or 40%).
DP from what I can see is DP=(200*p)+(100*c) rounded. p is piercing, c is concussion.
Next we have normal multipliers. These give a DP boost of either x1.2 or x2 based on the amount of normals a component has. weapons with less than two recieve a x2, two or more receive a x1.2.
for example, a mechavore disk has a base dp value of 510, a dp-hp ratio of 1.12, and 4 normals giving it a 1.2x multiplier
if you multiply 510 by 1.12, and then again by 1.2 you'll end up with 685.44, the listed dp value in 2.2
The main issues with this system are the weapons that are classed as 1.5 having normals. These get a x2 boost despite being far more easy to use than weapons with single point(1) normals. This is the reason things like typhoon and ripping teeth have such high DP, they're getting a x2 bonus for something that should've been reserved for things such as spikes. despite what some may think, rep disks only receive a x1.2 for their normals.
The exception to this rule are the various axe heads, frenzy hammer, and overkill blade. These get a x2 due to their use case as hammer weapons, despite having two or more normals.
there's a few other things that goes into 2.2, but I'm typing this on a phone and it really sucks so maybe next time.