Chose "A" variant for the armor and ammo bonuses and adjusted it's running speed Mist Lynx-ish to save mass and also to reduce the running-around-the-confused-assault circle radius. The concept is to either peek with the HMLs from a moderate distance and leech with the HMGs CQB, OR shoot 'em both when directly behind a clueless victim; the initial 30 damage followed up by the constant 12 DPS combined with the tight circle radius will let them know you mean business. _
https://mwo.nav-alpha.com/mechlab?b=975e6dc2_PIR-A _ 20 kph is a lot to lose on a mech that survives mostly on mobility. Here is a bit of a compromise that gets you up to two whole tons of ammo.