In World of Tanks, the self-propelled guns' (SPGs, or artillery) range is determined much more by projectile motion than the standard LOS guns on the tanks and TDs. In the spec sheets for the guns or chassis though, it doesn't offer any clue as to how far they can actually shoot. Where is this information?
I too wasn't able to find any numbers concerning the range of SPGs. However, range is only a problem/limitation in low-tier SPGs. With almost any mid-tier or high-tier SPG, you can virtually cover the entire map from your starting location. Only few very high caliber guns' range (gw-tiger's, etc.) remains insufficient to reach enemy base in high tiers, which didnot consist much of a problem for me. (I have researched and played up until Gw Type-E and Object-261)