This guide should help you to play without lags or frame drops.
This guide is based on my experience. I have GTX 760, 8GB RAM, and Intel i5-4670k.
If your PC's specs are similar or better than mine, then this guide should definitely help you.

It seems that one of the main problems for frame drops is because of Supersampling. Try to avoid using it.
If you don't like how the game looks without Supersampling, like me, then set Post Process Anti-Aliasing to SMAA T2x. It's not as good as Supersampling but it will offer a similar result.
Or if you don't really care about it, you can set it to FXAA or SMAA 1x or even OFF.
Here are the settings:
-Set your display options, then set the rest of the settings.
-Recommended: Set Texture Resolution to High. It will not show any big difference in the graphics, and it will make your game run significantly smoother.
-Shader Preload reduces stuttering during gameplay, especially during the first 3 or so minutes of a match. However, it increases loading times which may cause losing connection to the lobby.

This is how the game looks like on my PC with those settings:

This is an optional step, I've done it but you may skip it if you want. Open NVIDIA Control Panel by right-clicking on NVIDIA icon on your taskbar and choosing the control panel, or by right-clicking on your desktop and choosing NVIDIA Control panel from the list.
Once it opens, go to Manage 3D settings, then choose Cod:AW. It doesn't matter if you choose SP or MP, your settings will be applied to both of them. Do as shown in this pic:

-Even if you have a very powerful PC, but have some connection lag, you will get some stuttering during a match because of the lag, not your PC. Also, that lag will give you a disadvantage when you face a player with a higher ping because the other player will notice you before you do.