sniper rifles need lot of practice. and you cant quick scope because accuracy will become normal only a second after scoped in.
it is still a one shot kill to the chest (at close) and head i.e, if you properly manage all the factors that affect the accuracy like suppression, sprinting-stopping-shooting, aiming down the sights, holding breath etc. highest accuracy will be when you are lying prone with your gun on a bipod, holding breath without any suppressive fire.
anyway there's a lot of difference between recon and a pure sniper. first and foremost task of recon is to spot and only pick targets when you are sure you can one hit kill them (eg: ppl who are standing/prone like a statue, ppl running in straight line etc). dont keep on spamming shots on people who are jumping around unless you are in TDM and with a auto sniper rifle 
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