I suppose the author counts the University of Texas as being government? They were able to propel a 185g projectile at 1900m/s which is nearly 700kJ of projectile energy, wheras this appears to be at best 1kJ of projectile energy.
[edit] Just found that in the 80s they achieved an 8.8MJ launch; their later designs were lower energy but could fire repeatedly.
I believe the UT people are also behind the US Navy's railgun project. They also developed a railgun howitzer in the 90's. Perhaps that qualifies them as "government".
[edit] Just found that in the 80s they achieved an 8.8MJ launch; their later designs were lower energy but could fire repeatedly.