[dami]

The tables shows how different weight BBs would work with your m700 clone.
The formula is:

m1/m2=V2/V1

can be applied to find fps or m/s and then convert.
m1 and m2 is the weight of BBs. Starting with store 0.2g BB at 500fps and
keep going.

The formula is the horizontal maximum distance traveled by a BB=Xmax:

Xmax=Vinitial * (radical of (2*h/g))

Vinit= initial speed of BB when leaving the barrel
h=1m(measurements made at 1m height)
g=9.81m/s2(gravitation)
example 0.36g
Xmax= 83.33 * (radical of(2*1/9.81))=37.62m
To find the m/s or fps of your beloved m700 using 0.36g BBs:
m1/m2=V2/V1--->0.2/0.36=V2/150----->V2=(150*0.2)/0.36--->V2=83.33m/s

(150m/s)500fps-----------------------------0.2g_____Xmax=67.72m
(120m/s)400fps-----------------------------0.25g____Xmax=54.18m
(107.14m/s)357.14fps--------------------------0.28g____Xmax=48.37m
(83.33m/s) 277.77fps--------------------------0.36g____Xmax=37.62m
(69.76m/s) 232.55fps------------------------0.43g____Xmax=31.49m

These are measurements made on paper with formulas without taking in consideration the wind speed, rain, temperature or even the air friction.
Use them if you wish. They are accurate if the M700 is left to the same speed. If tweaked to higher speeds with 0.36g to reach 400~fps not sure if a smart idea. As you see it's already around 280~fps but for some people that's not enough.
Have a look and tell me what you think,
Danny