When word started going around that there was an Orkish horde moving toward them, the aid station was abandoned, and the defences that were easily torn up were repurposed for other parts of the defensive line. Most of the Grenadiers didn't even need to be told, they just grabbed anything that wasn't nailed down too firmly and pulled back to the easiest points to defend. They piled up traps and concertina wire and anything else that might slow down the greenskin advance, and when that was done, they started digging shell scraps and machine gun nests. The 3003rd was a flurry of activity right up until the Orks actually appeared. By the time they'd gotten close enough to see, all of the heavy weapons had solid positions, and everyone else had some sort of cover, even if it wasn't ideal.
The very instant the enemies of man appeared down the boulevards all around them, the sergeant major, who'd shown up at some point much to the bewilderment of his troops, began bellowing orders with the sort of commanding presence that only a sergeant major could muster. "Grenadiers!" he hollered, nearly reopening the only recently staunched wounds on his temples that he'd sustained the last time he'd commanded anyone. The pause this time was incredibly brief, as Strathcona's Raiders had been expecting such an order. "Attack!" the bellow still came later than most liked, but the reaction was awe-inspiring. The volley of grenades was swift, and the follow-up actually stopped the green tide in place for about as long as it took to empty a lasgun charge pack when it was set to maximum.
The grenades went off right about the time that all of the mortars and recoilless rifles the Grenadiers had left fired their first volley. By that time the heavy stubbers were in full swing, and the rest of the soldiers were blazing away as fast as they could. There were so many orks they didn't even have to aim, and ammunition seemed to disappear faster than the candy in a store invaded by obese children. Hope wasn't far behind, but the determination of the Grenadiers was unmatched. Their senior NCOs even had the sense to run off and plunder ammunition from anyone that wasn't using it properly, rushing it back to their gunners who could employ it properly in the name of the Emperor.
The whole time, Felix was blazing away with his plasma gun. He'd set it to its lowest setting and was using it more like a jumped-up hellgun than a proper plasma gun, rapid-firing away with the rest of his section. But the Orks just kept coming. Every time one of them got shredded by lasgun fire, at least two more appeared in its place, and pushed their way close to imperial lines. Then, to compound the problem, rokkits started going off haphazardly, up and down the defensive. Corporal Hazard did his best to keep his section together and firing, but all of that went to shit when a rokkit went off right next to him. The only reason he didn't evaporate in the explosion was the fact that the man next to him was in the way. So instead of getting vaporized, he just got covered in pink mist, and was left to keep fighting. Roaring in anger, he kept blazing away until his plasma gun overheated, and then he pulled out his sidearm and emptied that into the on-coming horde.
That wasn't enough, of course, but by the time he had it reloaded, his plasma gun was cool enough to keep going, so he brought that back to bear just in time to realize that the orks had closed to flamer range. The Brontians and Xenonians had rushed forward then, all of their flamethrower-toting troops opening up until they melted down the nozzles on their flamers and their tanks ran dry. More rokkits went off, and the remaining Brontians and Xenonians rushed into the fray, almost gleefully engaging the Orks currently hacking their way through the defences set up to delay them. And the whole time, greenskin artillery went off indiscriminately, their gunners obviously uncaring of anything but putting rounds vaguely downrange.
When another rokkit went off and left Felix flat on his back, deaf, with his ears ringing and his vision swimming, and his chest cavity aching from the force of the explosion, he decided they needed to do something more than just start rushing into close combat. Of course, with no more ammunition, they didn't have much choice. Even the heavy weapons were dry, and anyone who wasn't was down to their sidearms, or anything they'd pilfered during their down time. The Iceman found he had a few more shots left in his plasma gun, but he was out of cartridges. Lucky for him, though a few more shots was all it took to slow down the breach emerging in the defensive. His comrades rushed in to try and stem the tide once he'd piled a trio of Orks in front of their position.
Then, because his primary weapon was empty, and he didn't know what else to do, the soldier grabbed his revolver in one hand, and his laspistol in the other, and he pointed both in the direction of the enemy, and mashed the triggers until they were empty. Reloading his revolver was out of the question for the moment, so he tucked it away again, and mashed his last charge pack into his laspistol. He didn't get a chance to burn it off yet, though, as he spotted a fellow warrior in dire trouble. She was missing an arm and a leg, and laying just behind the defensive blazing away with a plasma pistol that obviously hadn't been issued to her. Admiring her spirit, the corporal rushed over and began rummaging through what passed for her tactical vest.
"Where the fuck is your IFAK?!" he demanded rhetorically, not sure where an entirely different regiment kept theirs. He gave up when he was pretty sure he'd ransacked every pouch she had, and resorted to tearing the tourniquet off his left arm to wrap it around her severed leg. "Keep shooting!" he growled, shifting out of her way, and putting his fully charged laspistol on her chest so that when her plasma pistol ran dry, she could keep shooting. Then he torqued on the tourniquet until the bleeding slowed down to a reasonable pace. From there, he had to tear into his own first-aid kit for a bottle of coagulant. The tourniquet was nice, but if it put it on any tighter he was worried something might explode, and he definitely needed to stop the bleeding if he wanted this woman to survive. He dumped the bottle all over the wound and almost instantly the white powder turned red as it hardened and sealed up the wound.
Then he turned back to the melee going on terrifyingly close, and he knew there was only one thing left to do. Hopping to his feet, the grenadier hauled the woman he'd just saved up onto her one good foot, and supported her with his shoulder under her severed arm while he quickly mashed fresh rounds into his revolver. "Raiders lead the way." he spat defiantly as he plugged away at the Orks still putting everything they had into getting through the defensive line. Whatever was driving them, it had to be horrifying, as even in the most dire of circumstances the greenskins had always broken on the violent bulwark that was the 3003rd's Grenadiers before. That being said, they'd always had more ammunition back then...