The point of not getting a sniper rifle to start with is for several reasons, which I will outline:
1) A properly upgraded sniper rifle can cost upwards of $1000. Things you'll need (in no particular order): Tightbore barrel, hop-up chamber, spring, spring guide, piston, barrel spacers, trigger, scope.
2) Airsoft sniper rifles do not tend to outrange AEGs out-of-the-box (see above). Even fully upgraded, they do not significantly outrange AEGs. This means that, either way, you're likely to be in-range of your opponents, so if you miss you will get lit up.
3) You will always, always, ALWAYS be out-gunned by your opponents. This can really wear down your morale, especially if you're not used to it. This apply doubly if you also are still learning and are thus not good at being a sniper.
4) It's ALL about your ghillie suit. If you get a sniper rifle, you will HAVE to own a ghillie suit. Most people make their own, since it's cheaper and better. This is painstaking process though, which is continually ongoing. When you reach the field, you will need to "update" it with local foliage. Don't forget to ghillie your rifle too...
5) Patience is essential; being a sniper is a slow game. The distance you move is often measured in inches, not feet.
6) Being a sniper does not mean camping. Expect to take flak from people if they had to spend 30 minutes trying to find you, because you didn't move from your spot.
Basically, being a sniper is HARD. It's like loading up an FPS you've never played and starting off at the highest difficulty: you're GOING to get your ass handed to you.
If you can deal with that, that's fine, but I (and the WHOLE airsoft community) can't recommend it.
I played airsoft for 2 years before I even considered buying a sniper rifle and making my ghillie suit.
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