what's even the point of the SIG spear?
The point is that the US Military is stupid
It's for Level IV body armor.
Years ago I wrote a post in this very thread about how in my opinion, without specialized tungsten carbide penetrator ammunition, Military loadings of 6.8x51 with an "Enhanced Performance Round" style copper body and external steel penetrator probably can't penetrate body armor either at all or at any considerable distance.
I have my doubts that the Sig Sauer 6.8x51 Hybrid cartridge is the Armor Obliterator that people on the internet make it out to be
And even if Big Army was able to mass issue tungsten carbide core ammunition (they can't and wouldn't) two things
1. It would be comparatively trivial to make armor that can resist said ammunition, especially at any "real" distance. Adept Armor advertises a 6.5-8lb plate that they claim offers protection against M993 at 3050fps and there is no reason besides cost that "near peer" forces could not copy this technology (it would be trivially easy to acquire one and ship it out of the country for analysis and reverse engineering)
2. Small arms do not win wars, this is not to say that having advanced small arms is stupid, but in the grand scheme of things, small arms really do not matter, for every GoPro video you see of a guy getting hosed down in a Donbass Trench 100 guys are turned into mist by nameless faceless Artillerymen.
So I found this fellow who had made his own Bullpup and it actually is quite an interesting design
-Dubbed the MBAR (Modular Bullpup Automatic Rifle)
-Two patents filed
-Polymer Lower, 7075 Upper
-Uses standard AR-15/10 bolts, barrels and cam pins.
-Modular magazine wells for STANAG, SR-25, AKM and AK-74 Mags
-Ambidextrous AR controls, Back up magazine and bolt release in the rear
-Downwards ejecting
-Not hammer fired but striker fired.
-F2000 "Breach cut" to allow access to the internals, think of it as a Jam door on ye olde Nerf Gun
-90 parts, 50% are COTS, 25% can be 3D Printed or Injection Moulded and 25% have to be machined
-Short Stroke piston with 3 setting adjustable gas block
-Aside from the recoil and piston spring, EVERY other spring is the same size, same goes for torx screws and roll pins.
-Magwell and trigger group will be open source designs
-Designer wants to license the design to an established manufacturer like DD, KAC or LMT
-Bolt is rotated 90 degrees and the cam is on the right side instead of on top
-OAL is about 30'' with an 18'' barrel
I have serious doubts this will ever make it into production, But I wish all the best towards this guy.
Continuing on the bullpup train
A guy on reddit made a Bullpup conversion lower for FM-15 uppers. Site won't let me copy/paste the pictures so here's a link to the post.
This guy, who was dormant for more than a year, has returned with an update and refined design as well as Jakl compatibility
ADS Assault Rifle
ADSh "Bars" bullpup by the guy who created the Gepard PDW, might also have been modified to be able to shoot underwater without issue?

Same guy also created the "Smerch" Design which has a bizzare seemingly mostly wooden construction (this was due to the creator at the time being a student at Tula Higher Artillery Engineering School and was a submission for the trial that eventually produced the AKS-74u)
Also made the "Shkval" design that was specially adapted for firing underwater

Many of you may be aware of the AK-74MB but are you aware of its creator Vitaly Vitalievich Boyarkin and his horrific Norwood?

or his AKS-74uB design? (Yes, Bullpup 74u)

Bullpup conversion from the Pre-SMO Luhansk People's Republic

PRSh machinegun, a a very special PK series bullpup conversion as it was created in collaboration with the Degtyaryov plant itself.

Pakistani police officer with FAMAS, what happened here is that a Talib took a FAMAS from a Frenchman, possibly sold it to another guy and said guy sold it to the Policeman.
Lastly Russian company Pufgun has created both disintegrating and non-disentegrating Polymer PKM Belts