The day after I posted this thread all of the gun adders here disbanded, and the final one made a thread verifying that I was correct.

You can now do it for yourself here
http://www.mpgh.net/forum/201-allian...uns-adder.html

Originally Posted by
proToon
In my opinion to add a gun of a choice, one would have to pinpoint the execution of an item being added to your inventory (buying a gun out of the shop), copy it, replace the item code of purchased gun with gun ID of choice, and then execute. That would assume someone would have the euro required to buy the item used in initial execution. I have not tried it, and I will not be (there's no point in doing jail time over a video game) but I would assume that's around how It's done using basic video game packet editing knowledge. If not, it has to be server-sided, meaning they're literally hacking into the servers to edit the data. Highly illegal.
P.S. I'm sorry in advance if I figured out the "secret" but this is taking hacking to a whole new level.
You might as well be money laundering.
In a normal circumstance I'd keep it to myself, but seeing as this hack is useless to me (dealing with actual legalities), I thought I'd lend an idea to those of you who keep asking the people with gun add scripts how they do it. Typically in MMOs you can't actually add something that isn't there, you have to manipulate the system to add it when it thinks it's adding something else.
For example, round-skipping, takes a typical action (adding a box), manipulates its values, and executes it, giving the desired value instead of the intended one. In this case, you use a typical action (buying a gun), manipulate the value of the gun ID, giving the desired gun instead of the intended one.
If you're wondering where I got the idea, I've been using CE for 6+ years on probably 10+ different games. The functions are typically around the same, just written and executed differently.
Another thing I've been seeing people using is ArtMoney, which I used to use on Runescape back in the day.
You can find ArtMoney tutorials on google. The thing is, ArtMoney is client-sided.