Section VII-A-08: Velocity Comparison Using 0.88 Gram 6mm BB's

Note that the charts display muzzle energy rather than muzzle velocity.  This was done for the sake of consistency.  For this section, the muzzle energy can be compared to the equivalent muzzle velocity if 0.20g BB's are used, as well as the actual muzzle velocities for the given BB weight. 

Energy0.20g0.88g
0.37 J200 fps  95 fps
0.47 J225107
0.58 J250119
0.70 J275131
0.84 J300143
0.98 J325155
1.14 J350167
1.49 J400191
1.88 J450215
2.32 J500238
2.81 J550262
3.35 J600286

Before I modeled the 0.88 gram trajectories, I purchased a pack of them and tested them out.  The reason for this was that I did not believe that such heavy-weight BB's could dramatically improve accuracy and range.  While the higher density of the BB's helps to decrease the rate at which energy is dissipated, the same high density works limits the ability of the BB to benefit from hop-up.  Because of the heavier density, it is very difficult to impart sufficient spin upon the BB's to achieve noticeable lift.  There are two factors at work here:

1.  The heavier BB's require relatively high spin in order to generate lift via backspin.  Because the BB's are striking the hop-up at a relatively low speed, it is nearly impossible to impart enough spin on them generate positive lift. 

2.  The heavier density translates to a higher rotational inertia that the hop-up must overcome. 

Observation matched theory as I was never able to fire the 0.88g BB's in such a way that noticeable lift was generated by hop-up.  At best, the low spin imparted upon the BB served to generate negative lift as V/U was sufficiently low to incur reverse Magnus Lift.  Even so, any appreciable gain offered by using such a heavy BB would be offset by the necessary increase in MED.  For instance, even if adequate hop-up could be applied, a 3.35 J shot would have an effective range of about 280 feet, but an MED of... 260 feet, making them useless for airsoft purposes. 

Model runs showed that it would take a moderately high spin rate to generate Magnus Lift (very high V/U), however it seems impossible to achieve such in practical terms.  Consequently, I have only included plots that do not concern hop-up trajectories. 

 

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