I see my suggestion for the S&W 500 was carried over
The M8 is a neat rifle. Lightweight but still to expensive to mass produce for the military. The 4id is known for getting to test out prototype and experimental software and hardware. I got to hold one of these once but never got to fire it, unfortunately. The problem with having this in the game is that it isn't an issued weapon so no military installations outposts would have any. The 500, however, is a hunting revolver. I own a similar one chambered in .454 casull, and let me tell you, you have to hold that thing with both hands or it will fly off.
So to address the jug armor. First and foremost, whoever designed the textures/skins for the jug armor pieces, please, please, please, change the helmet from looking like an angry soviet gas mask to something more modern like the older m40 or the FM50 gas mask. That is what most of the U.S. Army and Marine Corps use.
Now about possible t5 weapons being introduced: There could be a kit or two added to the kits or replacing one or two of the preexisting ones that use an rpg launcher and turn them into anti-tank/anti-armor kits. Now the Immortal Heavy kit is more of a heavy soldier kit. If we do get another recoilless rifle, it shouldn't be the most advanced one, it should be the AT-4 launcher as it's been around a while just like the RPG-7.
So if T5 weapons are introduced, they could be looted, found in legendary crates, or in military installations as very rare loot. One or two could be sold by Rick for 15 to 25 thousand credits. They would use the same ammo already in the game. Now here's the catch! This would have to be coded in, but if a player is wearing any piece of jug armor, they cannot fire one of these weapons. If they have one equipped in their hotbar, they cannot put on any jug armor. Basically it'd be like trying to dual wield AK's and fire them. You can hold them, but they won't work because certain requirements aren't met such as having two arms.
This would mean that those that want to wear half or full jug can only use the weapons that are available now. But those that wear Riot or below, can wield these weapons. Here's another catch! Like the RPG, that seems to do nothing to zombies, these weapons would be similar in effect to players not wearing jug armor.
T5 Sniper RIfle:
Say the 5 round 25mm Barrett XM-109 sniper system, which basically fires a bullet that acts as a supersonic grenade, was added as a T5 weapon to exceed the current .50 cal Barrett amr sniper system. This new more powerful weapon would only be as powerful as the golden barrett on a player wearing riot or less, BUT if you shoot someone wearing jug armor it adds a debuff such as 6 secs bleeding, 3 secs slow, 2 secs of impaired vision, and requires an amputation, as the normal barrett can blow a target's arm, leg, or head clean off. This now disabled jug, would have to limp to safety. Or be literally shot to pieces.
Now in order to keep players from just pounding on a jug till they're dead. The 109 would have a very slow fire rate and require the player to reacquire their target again by having to look down the scope again (due to the recoil). Like the winchester, This rifle would consume entire sniper rifle magazines per shot. Or a new 25mm ammo could be added that is expensive.
AT-4 Anti Tank Recoilless Rifle:
The AT-4 has been around for a while and used to be the standard anti-armor/anti-soft target launcher the US as well as several other countries use/used. A lot of the times it was used as a single use weapon in which case it was discarded after firing. This could be a consumable weapon with 1 shot already in the magazine, and no buyable ammo type (not to be confused with infinite ammo like the flamer). Like the XM-109, it would have the same effect the RPG does on zombies and players wearing riot or below, but would be devastating against someone wearing jug armor. The speed at which the rocket flies at would be two or three times that of the RPG-7, and it could be capable of bringing a 500 dura piece of jug armor to below 100 or more. A player would only be able to have one of these in their inventory at any given time, and that includes backpacks, pouches, and duffles. It would also cost a lot from rick.
T5 Shotgun:
Yes, I'm bringing this up because I think I might be onto something. Take the model of the double-barrel shotgun and cut it down so that it is essentially a sawn-off shotgun. This shotgun would deal a lot of damage but have such a limited range (like 10 block or less), that it would only be useful for indoor or cqb situations. It will still take time to reload (while you're being shot to pieces if you somehow missed your mark).
Another option would be to cut the weapon down even further so that it become a double-barreled sawn-off shotgun pistol. In this case it would be technically classified as a pistol so it could be dual wielded, but would be in the shotgun category, and use shotgun shells. this pistol would have the same properties as the spas, but with maybe 2 to 3 more pellets. An alternative to buckshot would be slugs. You'd fire 4 of them very close together. Like the 109 and AT-4, These would do an increased damage to jug armor. These dual wielded pistols could be the one chance you get to 1 shot a full jug point blank. I feel if you can get that close to a full jug and take them out in 1 or 2 hits, you deserve to take that armor.
The downside to dual wielding the shotgun pistol is that you would have to unequip one of them to reload the one in your off hand, then reequip the other to reload it as well. This would involve having both shotguns in your hotbar, switching weapons, and reloading, all while trying to fight. If you missed your mark, then you would need to quickly unequip your off hand, or switch to a regular pistol in order to continue fighting. This would leave you at a terrible disadvantage. You would need to nail your target the first time, or probably end up dying.
So this would encompass getting close to your target, maybe as close as 10 blocks, hope they don't hear or see you and stand still. If they do hear or spot you coming, this would mean literally dodging bullets to get close enough to hit a moving target with only one chance to do so.
.50cal MG:
The .50cal M2 Browning mounted machinegun could be put into the game, but with a catch. It could also be adapted to use the preexisting M60 model, too. You could carry this weapon with you and mount it in place. Once mounted, you could only aim and rotate but not move, making you a sitting duck. There are pros and cons to this. The pros are the ability to pin down other teams or players with harassing or suppressing fire as well as covering fire for your team. This weapon obviously would be more powerful than the lmg's.
In order to mount the weapon it would be similar to activating the optics on a rifle or lmg, except you wouldn't zoom in. This mounted mg would have only iron sights and a teammate might have to use a scope or binocs to spot for you. Also, this weapon could not be made to fire unless it was mounted (zoomed in).
I know these effects can be done as we already have a weapon or two that causes a debuff. We have all the arrows and potions that can do these kinds of things, and more can be added. Well that's my input for now on how to have your cake and eat it. And boy do I like cake! Especially getting to eat it! That's the best part, FYI!