As a BB Senshi Gunpla, especially when it's an older release, the posability of this Nu Gundam is foreseeably low, but I'm going to do it anyway. ^^
With support using Soul Stage Act 3 Action Support Clear Type.
A look at the kit's simplistic Heavy Weapon System (HWS) pack's configuration:
Just five additional parts needed to complete the add-on.
The one-piece Hi-Mega Shield.
The nozzles of the beam cannons were added in Part 7.
Comparison between the HWS pack's Hyper Mega Rifle and Hi-Mega Shield with their counterparts used by Nu Gundam.
The tab inside the rear skirt armor corresponds to the narrow slot behind the waist.
Getting the top face of the rear skirt armor to slide past the backpack for the part to be connected is harder than to get the armor's tab to lock in place behind the waist.
Due to the appended rear skirt armor, the bazooka's position has been pushed inward, causing the stock to collide with the back of the helmet.
There's no connector to attach the front armor piece to Nu Gundam's body, but the protruding tabs will lock onto the chest, waist and front skirt armor for the extra part to stay in place.
The armors do stay in place firmly, but they cut out the waist swivel. ^^;
More images of BB Senshi Nu Gundam in its HWS form:
Closeups on the details:
[Hyper Mega Rifle]
Probably due to its overall proportion, the HWS addons don't look as special as I hope they would on the kit. ^^ Hi-Mega Shield and Hyper Mega Rifle stand out due to their color and size, but not as outstandingly so as seen on the actual design. ^^ As it turns out, the HWS addons just give the kit a little upgrade in terms of bulk, and that's pretty much it. ^^;
Not forgetting the one-piece chest and front skirt armors also cut out the waist swivel. ^^;