On a lot of handguns, there are grooves on the slide to improve your grip when charging the handle. (racking the slide back to load a bullet into the chamber)
But how do I recreate these grooves? Do you just spam loop cuts?
The only thing that I could think about of for doing this based on the image you posted is using the loop cuts, I tried to recreate a quick similar situation on the images below:
1) create a number of loop cuts (CTRL+R and mouse wheel to select how many cuts you want) equal to the double of the amount of that stuff you want.
2)select the edges alternately (where you want the lower part of that stuff) and move them backwards.
3) select the other edges that you avoided before and move them to the right, so that in ortho view they are exactly above or in front of the edges youmoved backwards.
4) Dissolve any unwanted additional geometry (like the edges above that split the triangle faces in two for example)
I hope this helps you :)
What if I told you it's a sheared cuboid, multiplied with Array modifier and fitted in with Snap to the nearest edge? As the finishing touch use Ctrl+J.