Originally Posted by chaz
Prommy barrels are top of the line. If budget is an issue check out the Madbull barrels.
Doing a barrel polish is a cheap alternative for swapping out a barrel off the bat.
To increase shot consistency get a good hop up and hop up rubber.
"Prommy" here stands for Prometheus, a maker of high end upgrade parts.
The first thing to note about your gun is that its innards are ultimately cloned from the Maruzen APS2, so it doesn't matter that it's been called a "Shadow Ops L69" or anything else, you can just search for APS2 upgrades on this forum or other websites. Most airsoft spring snipers are internally either based off the Maruzen APS2 or the Tokyo Marui VSR-10. Keep in mind that APS2 is only the internal system and while internal parts for the APS2 will be compatible with your gun, external parts might not be.
With this in mind, I can more clearly answer your question. To upgrade your gun's accuracy, the most important parts are (roughly in order of importance) the hop up rubber (needs to be a hard type rubber if you're shooting ~2J or ~450 FPS with .20s), the hop up chamber (the PDI hop up chamber is good, and it lets you use AEG barrels and hop up rubbers), the inner barrel (6.03mm is considered about ideal), and the air/loading nozzle. Though these aren't really an upgrade part, probably the best thing you can buy to improve your accuracy is to use high quality heavyweight BBs, with weights of 0.3g or higher. Note that while it's tempting to install a stronger spring to increase your FPS, doing that won't have a significant effect on your accuracy but it will tear your trigger assembly apart, plus it'll make it hard to find a field that will let you use it.
Search around, try to learn as much as you can about upgrading spring sniper rifles in general and APS2/Type 96's in specific. Depressingly, it will probably take a lot of time and money to get a significant improvement, in the end you might end up replacing basically everything in your gun. Welcome to upgrading!