I loaded a few rounds with the 40 VMax and 40 Barnes VLC, both over 15.5 of Lil-Gun.

I noticed that 15.5 of Lil-Gun does not occupy much boiler room, even in this small case. Maybe 50% or so.

My question is, has anyone noticed any problems with Lil-Gun attributable to the light load density? In larger cartridges, light load density can cause problems...is it an issue with this powder in this cartridge??

Thanks,
BigIron

I believe 15.5gr of LilGun is considerably more than 50% capacity; irregardless, my loads with 16.0gr shoot great. Cannot recall the velocity spread, but would remember if it was bad. Velocity is usually above what the data states; another nice surprise.
I know they're extruded, but it is difficult to get 20-21gr of H322 or RL7 in a Fireball case, and my loads of AA1680 (18.0gr) comes almost to the neck. Have fun with the LilGun; it seems made for the Fireball!