Not to be confused with the Don’t Starve character Webber.
Basically space tasers, except instead of shooting electrical charges, it discharges a white, hot, sticky substance. A Webber is an exotic, non-lethal weapon used to immobilize a target. Used by the Adeptus Arbites, it fires masses of filaments, which expand in the air to form a web of sticky, near-unbreakable material. Targets are quickly entangled in a painful embrace; if they attempt to struggle, the filaments constrict even more, further entrapping them. Some may consider them as the Imperiaum's non-lethal version of the Eldar Monofilament Weapons. Although do take note that you can die from a Webber if you struggle long enough and suffocate from the bonds. In 40k tabletop, the only faction that seems to use it are Genestealer Cults, and that is due to the necessity of a lack of resources more than anything else.
The web pistol (also commonly known as a "glue gun") is a smaller compact, pistol version of the Webber. It is rarely seen on most battlefields, mostly being used by various police and defense forces for crowd control or for subduing an individual unharmed. It is noted for its distinctive under slung canister.
The canister contains a special glue-like synthetic protein similar to spider silk called web-chem. When the pistol is fired, a dark mass of tangled filaments entangles a target. As the threads are exposed to the air they expand and solidify, quickly forming a dense web of entangling sticky threads that contracts and binds the victim tightly, preventing all movement and action. The harder a victim struggles, the tighter the web becomes, and if the victim continues to struggle the web can eventually crush them to death.
On tabletop in 8th edition, Web Pistols make wound rolls against the lower of the target's S and T. Situational. It is a 1 point, 1 shot hand flamer, for what it's worth especially if you play Genestealer Cults.
The normal Webbers. The Webber has a cone-shaped nozzle and a canister. The fibres then shrink as the victim struggles until they are crushed. Some webs contain anesthetic meaning the prey will not struggle, making it better for hunting. Webbing can be dissolved with a special web spray. A Webber is an unusual weapon developed some time during the Age of Strife.
As mentioned, it is generally not seen frequently on the field of battle. It is mostly used by institutional forces such as the Adeptus Arbites for crowd control and suppression and its effects are usually debilitating rather than deadly (Doesn't mean the Arbites won't try though).
On 8th Edition, Wbbers make wound rolls against the lower of the target's S and T, using its S of 4. Situational rule but it's half a flamer for 1 pt with a 16" range (that can be used after running as well). Very good weapon for the Genestealers and a bit underestimated by many people. If you're playing Neophytes you should be either taking this or Grenade Launchers, else back to Brood Brothers.
The Heavy Webber is a larger version of the webber and web pistol and works on a similar principle to them, but on a larger scale. This is the gun you need when there is a large enough group of mob needing to get their teeth smashed inward or when there is a giant fuck huge riot on the streets and you can't resort to machine gunning them until they stop.
A lot of web material is fired from the weapon, totally immobilizing an enemy in an area several meters in diameter. It is very hard to break free once covered with webbing, but it can be dissolved with special web solvent carried by most web crews. The Heavy Webber is big enough that it can trap multiple targets at once and is the only Webber type that can be seen with some use in the military.