Don't need to, for a couple of reasons, aside from the fact that other than for sling-loading under helos, 105 towed arty is pretty well near out of the system now, and fading fast.
But the M546 APERS Flechette round is available for the M2A1 and M2A2, M101 and M103/M137/L119 *light guns*, throwing nasty little 6-grain steel flechette darts downrange...and there were the magnesium/aluminum powder *flashfire* rounds that turned a 105mm gun set for direct fire into a 100-meter flamethrower, an oversized version of the *Dragon's Breath* incendiary round for the 12-gage shotgun. I seem to recall one 9th Infantry 105 gunner getting his Medal of Honor for his use of 105mm APERS rounds when the NVA tried to overrun his base camp....
Of course I wouldn't want to have to hump the ammo for that bad boy.
I've always thought the ideal close in perimeter defense weapon would be a belt fed 12 guage loaded with a variety of 'specialty' ammo.
I used to have a few of those 'Dragons Breath' shells. Of course I got rid of them when I found out they're not legal in my state. Those babies really put out a monster flash. I've got a video of me firing them around somewhere. I'll have to find it.
Those suckers threw a wall of flame at least 60 yards.
Regards,
L