DPRK M-1978 Koksan gun:
Range estimated at "40,000 m" to "over 50km"
24 miles / 40 km = extended range full-bore hollow-base (ERFBHB)
30 miles / 50 km = extended range full-bore base-bleed (ERFBBB)
35 miles / 60 km = rocket assisted projectile (RAP)
[unqualified reports of up to 70km range are implausible]
Ammunition
* high-explosive
* submunition projectiles
* biological or chemical
Max Rate of Fire 1-2 rds per 5 min (estimate)
Max Speed 40 km/hr approx
Road Range 300 km approx
http://www.globalsecurity.org/military/world/dprk/m-1978-170.htm