Can you add a Gas Vent 3 system to an ARES HVAR, mod OR accessory?

Yes you can, for a full list of Restrictions check Pg. 148 of Arsenal

Ares HVAR: Th e Ares HVAR (“high-velocity assault rifl e”)
is another example of high-velocity weapons (see sidebar, above),
trading large calibers for a high rate of fi re.
In addition to the special recoil-reduction design common
to all Ares high-velocity weapons, providing 3 points of recoil
compensation, the Ares HVAR includes an internal smartgun
system and a rigid stock with shock pad. It cannot be equipped
with barrel- or underbarrel-mounted accessories.

Does that not mean it can't use a Gas Vent, seeing as a Gas Vent is a barrel/underbarrel accessory/mod?

Mods do not have a barrel/underbarrel etc. designation - you cannot mount a gas vent accessory on it, but a mod would be fine.

Note that many HV weapons have been depicted with multiple barrels, so some GMs may houserule needing multiple GV mods.




-k

Is that so? The descriptions never mention additional barrels. Do not confuse HV weapons with miniguns.

Much of the artwork has multiple barrels or what appear to be multiple barrels.

Not RAW by any means but GMs don't always base rulings off RAW.



-k

...Besides the Supermach 100, the Tactical Arms 73, and the HVAR itself, which HV weapons are actually illustrated? Those are the only three I could find, and of those only the HVAR might have multiple barrels.

Depending on the view there are also real life weapons that can be mistaken for having two barrels. The Bushmaster ACR (especially in the lower configuration) for example.

TBH I have never heard anyone claim that HV weapons use multiple barrels, except when confusing them with miniguns.

You know what? I am remembering the first time I saw the HVAR and HV LMG, which was either 1st or 2nd edition.

You can see the original artwork for the HVAR scanned in here (fourth from top), and the HV MP LMG scanned in here.

They were pretty clearly inspired by the H&K G11.



-k

The only reason some GMs think these weapons have multiple barrels is the original art work made them look like they did and in previous editions you couldn't put gas vents on them. You still can't add it as an accessory but you can as a mod. Since these guns only fire 2 more bullets than a conventional weapon, I wouldn't worry about them being 'over powered' by having gas vents added as they usually have lower damage and armour piercing capabilities. Besides, having multiple spinning barrels means you also need a power supply for the gun to spin those barrels, just like is mentioned in the minigun side bar but not the high velocity gun side bar.