Thunderbolt TDR-5S is a Heavy-class 'Mech in Battletech.
Despite its poor heat management, the Thunderbolt 5S is very well armed for its size, and has more armor than many 'Mechs ten to fifteen tons heavier than itself. As such, it can be found in front line service in all major armies.
The stock loadout has flexible weaponry and is very durable for its 65-ton weight class, with enough firepower at any range to be a decent threat. The heat management is poor, as stated; but as the weapons are spread across different ranges, heat becomes less of an issue if you only fire the weapons in their ideal ranges. Moving the ammo to the arms and legs is highly recommended (especially the LRM ammo in the center torso!). The legs are somewhat over-armored compared to the side torsos, so shifting some armor there is useful. Dropping the Machine Guns and their ammo bin to upgrade the SRM2 to a 6-rack is also helpful. Overall, the stock build is excellent after some small optimizations; though the heat management is just poor enough to be an issue in hotter biomes.
This standard 5S variant of the Thunderbolt is the only one with a Ballistic hardpoint (two, in fact). Swapping some of the Energy weapons for a cooler-running Autocannon is an option.
The Thunderbolt is best paired with an AC/10 or AC/20 and SRMs, since its generous armor and plenty of versatile hardpoints make it a potent force at mid to close ranges.
An alernative for long to short range nice harassement is to trade 2 ML for a PPC and the MG for SRM6 with 1 ammo ton. A good stability bash all the way up to melee.
A solid loadout is AC/5 with 2 SRM6 and 4 med lasers for good damage and maxed front armor. Having JJ is an option but consider what you have to give up.
The Thunderbolt 5S is well armed and heavily armored for its size. It's often deployed as a frontline 'Mech where the fighting is heavy, and it needs to give as good as it gets.
If faced with a thunderbolt, there is a fatal flaw that can be exploited to your advantage. The majority of the ammunition for the weapons is stored in the center torso, so if you are able to expose the structure, it is possible to detonate the ammo, instantly coring the 'mech. If you have a Gauss Rifle, targeting the CT can kill the mech in a single shot.