It is true that both paintball guns and gel blasters generally use much the same mechanism to propel a projectile – compressed air or gas. It is also true that paintball guns generally tend to be more forceful than gel blasters. So, it does not make much sense that paintball guns are legal and gel blasters are not.
However, paintball guns are not completely legal in NSW. It is important to know that the sale, supply, use or possession of paintball guns in NSW can still be a criminal offence. For example, it is an offence to possess a paintball gun outside an authorised paintball venue unless authorised to do so by a permit. Having said that, the maximum penalties for offences involving a paintball gun are significantly lower than offences involving a firearm (including gel blasters).