A team of myself and three others, all rather adept at Arachno Hunting, decided we wanted to push it to the limit and time-travel forwards into Nukem Academy; I had only done this once before, and you must bring your own weapons.
Upon our momentous arrival, the jerrycan of gin was shared until all Iron Liver holders were boozed up to nine thousand. Then we went in, and went in.
It appears your typical karnivore punk can wield a variety of weapons, from the .44 Magnum to a Shotgun, and right down to a Sledgehammer. You should be pretty ready to take and heal about 15 damage, with decent armor.
We had fair success and killed five or so of them, though we took a few losses ourselves. Fighting a gun-based enemy without Bleeder or Ultraclot, or a medic with a suture kit, is a very grim scenario. Your bleeding level will quickly jump up to 4, and you'll likely pass out mid-battle.
The other issue, which might be our imaginations, is that the karnivore punks like to follow you, and chase you when you run. It's not unusual to be calmly taking one down only to find two of his friends got curious over the gunfire. Writhing Smoke is a no-brainer on this one.
After, we all unintentionally figured out the MapQuest end-location of the garbage chutes in the Innsmouth. Two of us were too heavy to swim up, and K.I.L.R.O.Y calmly sat at the bottom of the water for about two to three minutes, before releasing about twenty five packs of cigarettes in a futile effort to escape from his watery grave.