Overall, I really liked this idea, but there were a few things that stuck out to me. The sidearm, rifle, MMG and HMG seem to me to be a tier high for what they are, and the frame weapons I feel like need a bit more discussion to flesh out what they exactly are to figure out what tiers they should be.
In general for this project, I feel like it will be very useful prototype for future firearms technology pages, so it might be useful to go back and look at existing stuff to make sure that these make sense since I think that future examples will follow the pattern you used for the different weapon examples.
It might help to include basic definitions for what you mean by "Service rifle" and "Support weapon" (or Support Rifle) or other terms like that, and I feel like some confusion could be alleviated by including a firing rate column in the quick info table under the pricing header, just to give people a slightly better idea of how each weapon acts.
I love this whole idea though, and I'd love to see it polished so that we can follow this example in the future so that it's easier to make a family of weapons.