Introduction:
Getting a feeling for Dragunov's overall range and preferred spacing/range is a key to succeeding with him as you become more experienced.
Range 0:
There should be no surprise here, a fighting game without weapons/projectiles will tend to gravitate towards fighting at melee range, more specifically range 0. This is the range for his strong hit confirm tools such as 1,2,1 and b+4,2,1 (which can hit up to about range 1). Range 0 is also the range for his best tracking (non-homing moves) such as d+2 and d/b+3, as well as d/b+2 for tracking to his right and u/f+4 for tracking to his left. Dragunov also has two staple block attacks at this range, d+1 (+0, opponent recovering WS) and b+1+2 (+3 on block, KND on hit), which can be used to set up KND/W! traps.
Range 2:
It's great to play at range 2 because there's not many characters with range 2 attacks and if they do, they are usually very linear. Dragunov on the other hand has an above average repertoire of range 2 attacks that track surprisingly well. First and foremost Dragunov's two homing options can hit at range 2 with the ability to extend f,f+3's range by "run buffering" it. Dragunov's qcf+1 and qcf+2 can both hit at range 2 and even though qcf+2 is -14, it's nearly impossible to launch with many notable i14 launchers (e.g. Bryan JU) unless their back is to the wall. A perfect qcf+1+2 can also hit at range 2, punishing many push back attacks that are not -17 or worse (e.g. Paul non-clean range death fist). Finally Dragunov has f+1+2, an i17 long range launcher with tremendous damage potential and wall carry.
Ranges to avoid:
Since I omitted range 1, it should be obvious that it's in your best intentions to avoid range 1. At this range Dragunov has the most problems countering SS/SW. Also most of his long range pokes have (what I call) a lingering hitbox, or basically a hitbox that stays extended on recovery. Off the top of my head the notables ones are d/f+4, b+3, and d+3. All of these moves will hit at range 1, but on whiff all of these moves are also susceptible to launch punishment. The major benefit of playing at range 1 is that all of Dragunov's launchers with hit at range 1, except d/f+2 against abnormal hitboxes. The drawback to this is that he has no safe option at this range other than CH b+4,2,1 confirming, but is also easily stepped at this range.