Add the SKS, or a weapon similar to it for recon and engineer. Overall concept; taking care of two birds with one stone.

Often when playing as the Engineer, I find myself wishing I had an option for engaging targets at a longer distance than my SMG or SG can allow for, like on Iceland or Paradise.

Always when playing as Recon, I wish I had a gun that was a recon/skirmishing weapon rather than a sniper weapon. I usually hate playing as recon because I'm not a fan of sniping, and while I want to help out the team by doing things like place beacons and ziplines, I'm then kinda useless in combat. Not even using the SVD with a dot/holo helps, due to the limited ROF and weird hit reg issues that snipers seem to have. On that note it's very important that the SKS has a higher ROF than the SVD, so that you're not being clamped hard from pulling the trigger quickly.

So enter the SKS. At a stroke you now have a weapon that helps an engineer reach out and touch people, but won't out-do an AR/LMG/Sniper. For the Recon a weapon that lets them get into the thick of it more, but isn't going to outperform SMG/AR/SG/LMGs.

It'd also be a nice VR thing with having a different style of reload, with it having stripper clips, unless you take the coward's way out and use after-market droppable magazines, or that could be an unlock upgrade that comes with the extended mag.