I want to add the dp28 into the box and also make it pack-a-punchable.

Look up Zomb1eK1ller on youtube he covers it in his tutorial seris

1. Go to raw/weapons/mp/ and find the dp28 weapon file (probably dp28_mp, but I'm not sure).
2. Copy that weapon file to mods/MAPNAME/weapons/sp.
3. Copy _zombiemode_weapons.gsc and dlc3code.gsc from raw/maps to mods/MAPNAME/maps if they are not there already.
4. Open up _zombiemode_weapons.gsc. Search for "init_weapons".
5. Copy an entire line from another weapon and paste it in the correct section (ex: MGs)
6. Edit the weapon name to match that of the weapon you copied from raw/weapons.
7. Change the hint string to "Press and Hold &&1 to buy DP28 [Cost: ENTER YOUR DESIRED PRICE OFF THE WALL]
8. Remote the "&" symbol from in front of the hint string quotes.
9. Change the price near the end of the line to match that of the price you entered into "ENTER YOUR DESIRED PRICE OFF THE WALL"
10. Save and close.

11. Open dlc3_code.gsc. scroll down to the include weapons section.
12. Find the section for MG's. Copy a line from another weapon and paste it at the bottom of the MGs section. Change the name to that of your weapon name (dp28_mp).
13. Make sure that it is set to true (true = in the box, false = not in the box)
14. Save and close.

15. Open up launcher, got to mod builder, tick the dp28_mp weaponfile.
16. Tick the 2 .gsc files if they are not ticked already.
17. Add this to mod.csv:

weapon, sp/dp28_mp

18. Add the weapon to the wall in radiant if you wish.
19. Build mod, compile map, run, test.

If there is no sound I can help with that.
If you don't know how to add the wall weapon, I can help with that.

1. Go to raw/weapons/mp/ and find the dp28 weapon file (probably dp28_mp, but I'm not sure).
2. Copy that weapon file to mods/MAPNAME/weapons/sp.
3. Copy _zombiemode_weapons.gsc and dlc3code.gsc from raw/maps to mods/MAPNAME/maps if they are not there already.
4. Open up _zombiemode_weapons.gsc. Search for "init_weapons".
5. Copy an entire line from another weapon and paste it in the correct section (ex: MGs)
6. Edit the weapon name to match that of the weapon you copied from raw/weapons.
7. Change the hint string to "Press and Hold &&1 to buy DP28 [Cost: ENTER YOUR DESIRED PRICE OFF THE WALL]
8. Remote the "&" symbol from in front of the hint string quotes.
9. Change the price near the end of the line to match that of the price you entered into "ENTER YOUR DESIRED PRICE OFF THE WALL"
10. Save and close.

11. Open dlc3_code.gsc. scroll down to the include weapons section.
12. Find the section for MG's. Copy a line from another weapon and paste it at the bottom of the MGs section. Change the name to that of your weapon name (dp28_mp).
13. Make sure that it is set to true (true = in the box, false = not in the box)
14. Save and close.

15. Open up launcher, got to mod builder, tick the dp28_mp weaponfile.
16. Tick the 2 .gsc files if they are not ticked already.
17. Add this to mod.csv:

weapon, sp/dp28_mp

18. Add the weapon to the wall in radiant if you wish.
19. Build mod, compile map, run, test.

If there is no sound I can help with that.
If you don't know how to add the wall weapon, I can help with that.

ok,  I did all that, but the weapon is showing up as the default weapon(cow bell) in the box