Today I learned a new term: Magazine Well, it's the slot where the magazine is inserted, and I created a bunch of them.
I also made variations on the medium blaster center block, I made thinner blocks, which are perfect for assault and marksman rifles.
In the screenshots below you can also see some stocks I made yesterday but didn't include in yesterday's screenshots.
The third gun has "jaws" at the front, the 4 blocks are separate so you can customize the look as much as you want. I made another jaw block, maybe I'll show it later after modeling more blocks.