Build: This is a crit based build with 2 MG5s based on being able to deal the most damage and slice through enemies like a hot knife through butter.
Statsplit: The reason for the 8/5/2.9 stat split is to try and upkeep high survivability with the most DPS possible, 8k Firearms is brings you very solid base damage for your weapons and will allow you to crit harder when you land your crits. 5k Stamina leaves you at 280k Health, this will help stop most of the majority of low TTK weapons from melting you before you can get your berserker and with a good strafe you will be surprisingly hard to kill.
Weapons: The dual MG5s for this build are stacked with crit mods and bonuses to play into the build, the magazine option was chosen so i can reach my berserker as fast as possible while still having good crit damage. I personally wouldn't use a crit chance mag as the 4.5% increase (while not using rounding error mods) is not worth the 5% extra fire rate which is equal to a base 5% DPS and I don't use magazine size as a minor because these 5 extra bullets while being helpful for extra damage per mag they slow the first mag proc speed by around .3-5 seconds which could make a difference in a face trade or while shooting a strafing target. The pistol is used only to build your sig so get it at a low gear score so you can use both talents you should meleeing down targets with this thing when ever you get the chance to and if you're in a session with friendly rouges you can shoot them to build towards your sig with coolheaded
Weapon Talents: The reason I chose these weapon talents are as follows: Accurate allows you to move around with your MG5s while not having to worry about your bullets not hitting at an extended range or even sometimes at point blank range while being able to move around and not have to attach to cover 85% of the time. Deadly is pretty self explanatory for for a crit build while not being exactly 15% one you get up into the high crit dmg values its still worth taking. Unforgiving is chose as a damage talent because of the ease of use factor and the base increase you get from it, I don't use prepared as it is a wasted talent (in my opinion) as the range it requires it not going to happen enough with all of the people using SMGs and competent gets removed if you switch weapons and with the low skill haste the uptime on it is very low meaning its not worth it.
Skills: The skills on this build are mostly used as damage bonus stacking for more damage. some substitutions can be made if you choose to play in a group with a god pulse like using immunization box instead of pulse or a disruptor instead of your pulse. make sure you're changing your performance mods if you prefer a less strong heal and want a stronger pulse, bigger immunization box range or disrupt range.
Talents: The reasoning behind the talents are as follows: adrenaline is useful for cleansing every status effect in the game which completely neuters pred, shock and flame turret spammers, disrupt and flash sticky and while not as common it removes the intense or fire rounds effects. Critical safe is a life saver for many reasons and I think its very powerful if you use it 20% is nothing to scoff at and it really make a big difference to a face trade if you can pull it off. Precision is a slept on perk for PvP as it doesn't say exact values but I think the bonus from this can make or break any build with the pulse being 10% chance (estimated) and 22% dmg its a very strong pulse and better than your pulse at 2.9k electronics and all for one headshot makes it super manageable even on consoles. On the move is a free 15% damage reduction for any kill made on any target and is readily available for use in every situation
Weapons: Both MG5s could be replaced with Big Al id suggest using deadly and unforgiving on Big Al if you're using it since you will be using them while either hooked to cover taking advantage of the exotic talent or using it at point blank range like an SMGs, or if you want to use double Cassidy you can swap the glove out for the exact same rolled gloves with LMG damage rerolled to Shotgun damage. Cassidy Build Guide ( Here ) Big Al Build Guide ( Here )
Talents: The 2 talents I would substitute would be critical save and precision, i would replace them with strike back if you need more skills and you feel like you dont have a booster shot enough of the time, or combat medic if you're more into an off meta group play build.