Review: Amprex (Updated U32.1.2)

The Amprex is an MR10 beam weapon available from Clan Dojo research. Its high Crit, Status Chance and chaining mechanic make it a potent weapon against most types of enemies, especially groups. However, base Electric damage unfortunately puts it at a notable downside compared to its competitors.

Original posted on 04/02/2019, U24.2.12

Update posted on 05/11/2022, U32.1.2

Acquisition

The Amprex blueprint can be researched and then purchased at a Dojo's Energy Lab.

Stats

The Amprex has great Crit (32%/2.2x) and Status Chance (22%), giving it fantastic hybrid build potential. However, pure base Electric damage is a notable downside, restricting its elemental combination potential and reducing the number of unique procs it can inflict.

The Amprex is a Beam weapon, with a Range of 18 metres. As a Beam weapon, it consumes ammo at half its Fire Rate, just 6-per-second, resulting in an excellent Reload Ratio of 6.41. It also has the short damage ramp-up and decay inherent in all Beam weapons.

An AMmo Max of 700 is quite generous, and Ammo Pickup of 60 is very respectable, restoring 10 seconds of continuous fire at base.

The Amprex was one of the first chain Beam weapons. Upon striking a target, it will chain to up to 3 other enemies within 10m, dealing reduced damage with each successive chain. Besides the reduced damage, the chain beams inherit the same stats as the main beam.

Punch Through allows the main beam to strike multiple enemies, who will each produce a set of chain beams. This drastically increases both group damage but potentially even single-target damage, as the chain beams from different primary targets can target one another.

Augments

None.

Builds

Single Element 0-Forma:

Annoyingly, the Amprex has no native polarities, making Forma-less builds very barebones. This above build leverages the base Electric damage to form useful damage types with just a single elemental mod. The damage types possible with this setup are Electric, Corrosive, Radiation, and Magnetic.

Alternatively, you can temporarily drop Split Chamber down to Vigilante Armaments to fit a second elemental mod, giving more damage type options.

The obvious general-purpose elemental setup is Viral, as its proc is near-universally useful, even if its damage multipliers are not. The base Electric is at least neutral to the Health types that Viral is weaker against. Corrosive is much stronger against anything with Ferrite-armour, as well as having much stronger direct damage against most heavier Infested units. In particular, many of the Cambion Drift Infested are immune to Viral procs entirely.

Against the Corpus, the two main elemental setups are Radiation and Magnetic. Radiation is very strong against Alloy-armour, which is used by most armoured Corpus units. Otherwise, Magnetic is extremely effective for depleting enemy Shields, though there are not many enemies who have legitimately strong Shields.

Recommended Setups: Viral vs everything, Corrosive vs Ferrite-armour, Infested, Magnetic vs strong Shields, Radiation vs Alloy-armour

General Purpose 1-Forma:

One added V polarity means you don't have to compromise between Split Chamber and elemental mods.

Critical Delay is a strong alternative to Point Strike. Its extra +Crit Chance is always appreciated, and the Fire Rate penalty isn't the biggest downside, and can be easily compensated with a +Fire Rate mod.

Recommended Setups: see above.

Hunter Munitions 4-Forma:

Three added polarities, probably mostly Vs, help significantly in fleshing out a full build. The extra capacity gives a lot of seventh and eighth mods to consider.

Hunter Munitions is notable because it allows the Amprex to inflict Slash procs, which is of course normally impossible, and also takes advantage of its very high Crit Chance. It is by far the Amprex's best setup against Status-vulnerable heavily armoured enemies. While each Slash proc will be relatively weak on its own, the Amprex will inflict a huge number of them, thanks to high Fire Rate and Crit Chance. The armour-bypassing damage of the Slash procs, coupled with the damage amplification from Viral procs, will tear through most armoured enemies with ease, as well as scaling effectively into very high levels.

(Primed) Shred is a great mod option. As mentioned previously, Punch-Through is extremely strong on the Amprex, drastically increasing its firepower against groups. The +Fire Rate is ideal for offsetting the penalty of Critical Delay, and of course also increases DPS at the cost of faster ammo consumption. Other +Fire Rate mods can of course be used, but I feel that (Primed) Shred is the overall best option.

There are of course a lot of mod options for increasing your overall damage. A (Primed) Bane is the best way to do so, especially once you start acquiring Galv mods and Arcanes. In particular, the Faction Damage bonuses are applied multiple times to damage-over-time procs like Slash, Heat and Electric. However, they are quite expensive to max out, and can be inconvenient to regularly switch around for maximum benefit against most targets, not to mention the few Factions that do not have corresponding Faction Damage mods (e.g. Sentients).

For a universal damage boost, Heavy Caliber offers a decent amount of +Damage with a negligible penalty. Vigilante Armaments offers a smaller Multishot, but is cheaper to max and lower drain. Finally, Hammer Shot is also a fairly weak benefit but is not made obsolete by Galv mods and Arcanes, as it increases Crit Damage and Status Chance instead. The conditional Crit mods Argon Scope, Bladed Rounds and Proton Jet are also worth consideration if you can tolerate their trigger conditions.

Finally, you can consider a third elemental mod. Notably, this is the only way to get the other single elements besides Electric on the Amprex. Adding Heat alongside Corrosive is a very strong setup against the Infested, hitting just about all of their Health types super-effectively. Heat is also an all-round good element, and a decent anti-armour option if Slash is not available/possible. Unfortunately, Viral + Heat is not possible as the Heat will auto-combine with the base Electric to form Radiation.

Getting individual Toxin is very strong against unarmoured Corpus, as it will bypass their Shields entirely and strike directly at their often-weak Health. To do so requires combining the base Electric with Heat or Cold to form Radiation or Magnetic respectively. As mentioned previously, Radiation is effective against Alloy-armour, making Radiation + Toxin a strong all-round anti-Corpus build. Magnetic is especially potent against strong Shields, but struggles immensely once those Shields are actually depleted.

For the Exilus slot, there are two main options. Sinister Reach increases main beam range from 18m to 30m, which is a significant boost in usability in larger tiles. It doesn't affect chain beam range but that is not a big deal. Otherwise, an Ammo Mutation mod like Vigilante Supplies can be used to eliminate any ammo concerns, with Vigi Supplies in particular also marginally increasing damage.

Recommended Setups: see above. Also consider: Viral + Slash vs armoured enemies, Corrosive + Heat vs Infested, Radiation + Toxin vs Corpus

Galvanised Mods and Arcane

Galv Chamber of course.

Galv Shot should be used primarily in HM builds, and any other loadouts that add unique procs. With its base Electric damage, the Amprex is only capable of inflicting two unique procs with just elemental mods, which would put the damage from Galv Shot marginally weaker than Serration. The Slash procs from HM offer a third unique proc, which will make Galv Shot a fair bit stronger than Serration.

Galv Scope can be a good option. The Amprex obviously benefits from significantly increasing its Crit Chance, and being a Beam weapon can land headshots very easily and reliably. Perhaps the biggest issue is that only certain damage-over-time procs will trigger the Headshot kill condition, and unfortunately neither Slash not Heat can do it. Nonetheless, if your goal is to maximise Crit, Galv Scope can be a strong option if its playstyle suits you.

I don't think Fractalised Reset offers much to the Amprex, as its Reload Ratio is already exceptional.

The choice between Primary Merciless vs Deadhead is largely personal preference. Merciless stacks up very easily since the Amprex is so good against crowds, and the +Reload Speed is always a nice little bonus. Deadhead stacks up with fewer kills provided you land Headshots reliably, but more importantly its extra Headshot multiplier gives it higher peak damage.

My Build:

Fairly standard Viral + HM build, though I'd switch Serration to Galv Shot.

If I bothered to invest more, I'd put Sinister Reach in the Exilus slot.

Combat Use and Summary

The Amprex excels against groups. Its chaining beam allows it to do significant damage to several enemies at once, amplified massively with Punch Through. It is among the best non-explosive crowd clearing weapons in the game.

With very high Status Chance and Fire Rate, the Amprex is also quite effective against heavily armoured enemies, though unfortunately its base Electric damage holds it back somewhat. It cannot run a Viral + Heat build, instead needing to run Corrosive + Heat. The base Electric biases such a build towards Corrosive, which is suboptimal as you want to be stacking as many Heat procs as possible. Nonetheless, with such a build the Amprex will max Corrosive procs almost instantly, and stack very large Heat procs quite effectively on tough enemies. The combination of reduced armour from Corrosive procs and ever-increasing damage-over-time from Heat will do great damage even to heavily armoured enemies.

However, a Hunter Munitions build is far more efficient, leveraging the Amprex's great Crit Chance to reliably inflict Slash procs. Such a build can easily chew through almost any heavily armoured enemy quite easily, with maxed Viral procs drastically increasing the damage dealt by the many small Slash procs.

The Amprex is least notable against single heavy unarmoured or Status-resistant/immune enemies, as it does not benefit from its biggest advantages: its chaining effect and high Status Chance. It is by no means weak with great Crit, but it falls behind compared to many other primaries for raw DPS.

As a beam weapon, the Amprex has perfect accuracy and no recoil, however also has a limited range. In Warframe's primarily close quarters combat, the limited range is not a huge issue, though can of course be a problem in the larger tilesets and open worlds. It is best combatted through making full use of Warframe's many movement options, which can allow you to close to effective range extremely quickly.

Ammo Mutation/Case/etc can be worth equipping as well for longer missions. The Amprex's ammo efficiency isn't terrible, but in longer missions, can prove troublesome if kill times increase too much.

Overall, the Amprex is a strong weapon. It obliterates groups and can deal with armour effectively, whether with elemental procs or Slash procs from Hunter Munitions. It handles unarmoured and particularly Status-resistant/immune enemies less efficiently, but still fares well enough. In general, the Amprex handles the majority of Warframe's content just fine. Though I don't personally enjoy using it, I recommend giving it a try. It is overall one of the better Primaries in the game.

Scores

Vs Trash Mobs: 5/5 - The Amprex deals more than enough damage to easily kill weaker enemies, and its chaining mechanic allows it to tear through even large groups with ease. Any added Punch-Through is just bonus.

Vs Unarmoured Heavies: 3.5/5 - Solid but not exceptional Burst DPS with very high Crit, the Amprex can deal some reasonable damage to Status-resistant/immune enemies. Anything vulnerable to Viral procs can be dealt with much easier, as the Amprex excels at stacking them.
Vs Armoured Heavies without Forced Slash: 4/5 - Pure Electric base Damage is suboptimal, biasing a Corrosive + Heat build towards Corrosive. The Amprex will almost instantly max Corrosive procs, and progressively stack quite strong Heat procs, dealing very good damage to heavily armoured enemies. It will be especially potent against anything Ferrite-armoured due to the damage bonus Corrosive receives.
Vs Armoured Heavies with Forced Slash: 4.5/5 - Very high Crit Chance and Fire Rate allows the Amprex to inflict Slash procs with HM very regularly, however its low base Damage means each individual Slash proc will deal relatively little. Nonetheless, the Amprex can stack good numbers of Slash procs on enemies, 

Vs Variants

None.

Competitors

There are a few notable competitors that fill a similar overall role to the Amprex.

A Primary Vermisplicer Kitgun is the most direct competitor to the Amprex, as it also chains and can have very competitive stats. The above build is a max Crit setup that has similar range to the Amprex, but will deal significantly more direct damage. The Vermi's base Damages are also much better, with the full spread of Physical damage and even innate Toxin allowing very easy Viral + Slash builds. The Amprex retains a major advantage in natural Status application due to its Fire Rate, as well as better Reload Ratio and overall ammo economy, however I consider a high-Crit Vermisplicer as the overall better weapon. The Reload Ratio difference is not a major issue, and the ammo economy can be made a total non-factor with Pax Charge.

The MR9 Ignis Wraith is another potent weapon, leveraging a longer range (27m vs 18m), innate body Punch-Through, and small end-of-beam AoE as its anti-crowd capabilities. The IgnisW has a major advantage in base Damage type, as Heat is a more generally-useful element than Electric, especially for Viral/Corrosive + Heat builds. The Amprex has a much higher Ammo Max, though the two have comparable ammo-recovery rates. The Amprex inflicts a lot more procs, as well as dealing much higher direct Damage.

Overall, the two are rather different weapon types although they fill a similar role. 

Rivens

The Amprex has a slightly low Riven Disposition of 2/5 (0.85), which seems fair. It is currently rather powerful but not absurdly so, and is still fairly popular.

Naturally, Damage/Multishot/Crit Chance/Crit Damage are all great stats, although the former is less valuable once you get a high-ranked Arcane. An element can help to save a mod slot, or increase bias of a desirable elemental type (e.g. Heat for a Corrosive + Heat build). +Faction Damage can be a strong damage multiplier particularly for damage-over-time procs, most useful against the Grineer as they are generally the toughest. +Fire Rate is a significant DPS increase at the cost of also eating ammo faster. It is most notable for offsetting the penalty of Critical Delay. +Punch-Through is incredibly powerful on the Amprex, drastically increasing its damage potential against groups.

-Faction Damage of a Faction you're less worried about (e.g. Infested) can be a solid negative, though do note that it will severely reduce the damage output of damage-over-time procs against that Faction. -Fire Rate can be manageable for better ammo efficiency, especially if you have a +Fire Rate mod like Shred already installed, though of course it is a loss of DPS. -Mag Capacity/Reload Speed can both be tolerable in small amounts since the Amprex has such a good Reload Ratio. -Ammo Max can be very tolerable alongside one of Ammo Mutation/Case/etc. -Projectile Speed and +Recoil have no effect. -Zoom is perfect since the Amprex is only usable in close quarters.