I lately noticed that perk check disabling has a bit changed for some perk in SP/Survival mode. This might apply to Multiplayer mode as well. Perk check disabling are used to apply specific perk effect without equipping it.
I will take perk_WeapReloadMultiplier as an exemple.
To make a fast reload cheat in the newest Steam patch of MW3, you will need to patch 3 things though 1 is optional.
Code:
1: Reload Float Value ---> Read Float value of 0x1D398E8+C. This will give you the reload value that you can edit. Higher the number, the slower is the reload.
2: Disable Perk Check for Reload Timer ---> Write EB 00 (Hex) or 235 00 (Dec) to 0x00647770
3: Disable Perk Check for Reload Animation (optional) ---> Write EB 02 (Hex) or 235 02 (Dec) to 0x005770C9
In previous MW3 patches, the reload speed and animation were used in the same opcode so that you only need to patch 1 opcode to make it work. Now, Reload Animation and Timer and separated but uses the same Float value. Some "Perk_" might only need 1 changes like in previous patches but i'm not sure. Not tested yet.