- Gas can achieve a higher FPS, but as field legality... Spring is the way to go because unlike gas, your shots are consistent one after another.
- Gas rifles need to be re-sighted generally every time you pull it out because even 5-10 degree changes in temp can throw the hopup off.
- Gas has lubrication in it, which easily causes more inconsistancy with you hopup bucking.
- Spring rifles generally have a plethora of aftermarket performance parts.
- Spring doesn't have as many moving parts, less shit that breaks, and ultimately a rifle you can field strip without having to worry about losing anything.
- Aftermarket spring hopups can be fine tuned much better than a gas
- The only thing Gas has on spring is that it comes shooting hot, and you don't need to track parts all over the world to get your rifle shooting how you want. All in all though, if you want to be serious about being an Airsoft Sniper, Spring rifles are where its at.