This is my first build guide

So I don't think you can get much better than this for an Amprex. Does a tonne of damage, but it's really really forma heavy. Only invest in this if you have the time/patience, but if you do it's worth it.

Heavy Caliber

That damage bonus is way strong, and as it's a aoe weapon you're not really going to be suffering from the - accuracy.

[Amalgam Serration]

You're losing 10% damage for 25% sprint speed, this is a no brainer. The [Amprex] doesn't have that great range so it gets you into shooty range a bunch quicker.

[Vile Acceleration]

The debuff on the damage here is negligible for the amount of fire rate this gives you. This along with your [Amalgam Serration] loses you about 25% damage total, but you get 90% fire rate which means you can zap zap faster.

Rivens?

If you find a nice riven with the crit chance + crit damage you could swap out the [Vital Sense] or [Point Strike] but honestly with [Amprex] being such a high dispo you might struggle to find one with good enough stats. However if you do find one a decent one you could add in a [Vigilante Armaments], multishot on the [Amprex] doesn't give you more beams to work with but instead gives you a straight up damage buff which is nice.

Got any tips for me? Please let me know in the comments, I'd love to hear your feedback so I can make possible improvements. Happy hunting Tenno