When determining what can switch into Salamence, and how easily Salamence can switch in and out, people are making two assumptions. 1) That Salamence is holding Life Orb; and 2) That Stealth Rock is up on both players' sides of the field. However, these assumptions are not always true, and this makes Salamence significantly more difficult to counter.
While Salamence's most commonly used sets, Dragon Dance and Mix, both use Life Orb, Salamence can also use Choice or Leftovers sets. These are not just rare gimmicks; they are actually fairly common. Look at the item stats for Salamence from April:
Code:
| Salamence | Item | Life Orb | 67.0 |
| Salamence | Item | Leftovers | 11.5 |
| Salamence | Item | Other (6) | < 5.4 |
Life Orb was used even less in May:
Code:
| Salamence | Item | Life Orb | 64.6 |
| Salamence | Item | Leftovers | 11.9 |
| Salamence | Item | Other (6) | < 7.2 |
This shows that Salamence has more unpredictability than most posters in this thread think. One aspect of Salamence that is generally agreed upon is that once one knows its set, it can be countered, but that scouting its moveset is problematic. The possibility of Salamence holding something other that Life Orb significantly complicates this, since some of the checks to Salamence's LO sets fail to check sets with other items. For example, Choice Band Scizor can be setup fodder for Bulky Leftovers Mence. Similarly, the Pokemon that would outspeed a seemingly unboosted Mence might be outsped and 2HKOed by Scarfmence. But where alternate items have the biggest impact is in terms of passive damage. One argument against Salamence becoming Uber, that it takes 35% of its damage every time the Salamence user switches in Salamence and attacks. But for non-Life Orb forms of Salamence, this could be only 25%, or even 19%. This increases the number of times the Salamence user can switch in and get forced out.
But, you might think, wouldn't a Leftovers set instantly be revealed due to Stealth Rock damage and Leftovers recovery? This makes a second assumption, that the opponent has used Stealth Rock at all. As team support for Salamence and other Rock-weak sweepers such as Gyarados and Dragonite, players using offensive teams often lead with Stealth Rock-preventing leads like Azelf or Aerodactyl, both of which are highly likely to prevent the opponent from using Stealth Rock. This makes it so Stealth Rock is not always common when offensive teams use Salamence. Preventing SR this way doesn't get in trouble with the "with little support" phrase of the Uber characteristics, since it only requires the use of one support Pokemon and can benefit sweepers other than Salamence. This means that the Salamence user doesn't have to use a Pokemon solely to let Salamence sweep, so Salamence is still sweeping or "wallbreaking with little support."
In conclusion, when determining what can counter or check Salamence, don't assume that Salamence always holds Life Orb, or Stealth Rock is always up on the Salamence user's side of the field. Sometimes these are not true, and this complicates the job of preparing ones team for Salamence.