Airsoft Canada - Airsoft Sniper Rifle

wow, where to start....

"The ideal barrel length is between 350 up to 500 mm"
It only really matters on spring bolt action rifles, and not for the reason you think it does.
Although bolt actions have large cylinder volumes, and are pushing out very heavy BBs, there's a minimum length limit to their barrels in order to get maximum energy from your spring into the BB.
Because cylinders don't have PORTS in sniper rifles. So you can't let the piston accelerate freely then burst into compression, trading pressure for volume as you would in an AEG with a short barrel.

"They work as single-shot weapons, so they will not spray a lot of rounds if that is the style of play that you would prefer."
If that's the style of play someone prefers, why the hell are they buying a sniper rifle?

"The muzzle velocity should also be over 300 feet per second, with most being between 450 to 500 feet per second"
Speaking in muzzle velocity is dumb. Most sniper rifles will be between 2-3.3j, depending on local field limits. The muzzle velocity will change drastically depending what ammo you're feeding it.

"The less speed that your rifle has, the more time the BB has to drag in the air"
Actually, totally wrong.
The MORE speed your rifle has, the more drag the BB will have.
Firstly, the faster you go, the more resistance you encounter.
Secondly, a BB shot slowly has less energy, less energy means less range and less time in the air.
Lastly, you make no mention of BB WEIGHT anywhere in the article. How the crap is anyone going to hit someone 300ft away with .20s?
At 2j; a .20 is traveling 465fps, and a .43 is traveling a measly 317fps. But the .43 is going to travel 300ft accurately no problem what so ever. The .20 will be lucky if it hits a barn at 200ft.

"The ability to have a good effective range and the muzzle velocity depends greatly on the barrel as well as the fire power of the individual rifle."
1. Barrels don't affect range.
2. Having a good barrel means you won't lose any accuracy from imperfections. It doesn't "add" accuracy, it just prevents you from losing it.
3. "firepower" (I assume you mean muzzle energy) doesn't mean shit if you're not using the right BBs. A rifle shooting 1.3j with .30s will out range a rifle shooting 2j with .20s

"when it comes to sniper rifles, the three primary upgrades are the bipod, the scope, and the barrel."
No, no, and yes.
1. HOP RUBBER
2. compression
3. barrel
The fact you haven't mentioned hop systems in the whole page just underlines the fact you have no idea what you're talking about. The hop rubber is the single most important upgrade. Your hop rubber is the difference between lobbing BBs 120ft in random directions, or accurately hitting people 350ft away.

"While you might want a rifle with a semi-auto capability, such as the KJW M700"
"semi-auto" is when you can fire a BB with each squeeze of the trigger, without having to perform an action in between trigger pulls.
"bolt action" is when you need to perform an action to manually load a BB in between trigger pulls.
Try pulling the trigger on the M700 twice and see how many BBs shoot out.