First I am going to start out with this. YOU CAN NOT MAKE the following ammo types.
AP= Armor piercing, can only be bought/found
.50 Incendiary. Can only be found/bought.
Any special ammo you make CAN NOT be broken down, I.E. If you make 100 10MM JHP rounds, you have to use them, or sell them. They can not be broken back down into base items.
.38 special can be used in ANY weapon that used .357 (true IRL). However (also true IRL, but no .38's exist in game AFAIK) .357 CAN NOT be shot out of a .38.
If I have this right, both rounds are of similar size around, but .357 contains a larger powder load and is longer.
Surplus ammo deals more damage, costs less. The down side is weapons degrade faster when using it. Likely due to the ammo being "dirty" and poorly made.
Surplus ammo CAN NOT be broken down.
Each ammo type or "round" has base items that it is made up of.
Example 9MM
X amount of lead
X amount of powder
1 9MM casing
1 pistol primer
and you get 1 (one) 9MM round.
Shot shells are similar.
X lead
X Powder
1 shot shell (12 or 20 Gauge)
1 shot shell primer.
Here is a small (not complete) list of ammo you can make, please note that energy weapons are not included here.
Energy weapons can consist of, over charged and maximum power, maybe more.
The HAND LOADER perk is required to make some ammo. Similar perk for energy weapons. These also ensure you catch more shells/casings are they are used.
Every ammo type requires X amount of repair skill.
.50 match grade hand loaded requires 100 repair.
Spoiler
JHP = Jacked Hollow point. Its a hollow point bullet with a jacketed casing.
These rounds are good for punching through light armor (jacked) and killing whats inside it (hollow point)
HP= hollow point, good for killing soft things. I.E, geckos and dogs, unarmored/light armored humans.
AP= good for killing things that have armor, I.E Death claws, and Power armor.
JSP= Jacked soft point is similar to JHP
SWC= Semi wad cutter. Functions like a JHP round AFAIK.
AP Armor piercing, more armor (DT) mitigation, less damage.
Incendiary, Sets things on fire. .50 only.
12/20 G Slug. A sold shot from a shot gun, considering that 12 gauge is pretty large, thats about like a .50 from a shot gun.
Magnum, more powder, same shot. Longer range + more damage.
Coin shot, Uses coins. (never used before personally)
.308 Hand loaded
.50 Match grade hand load.
Basically a hand load is a higher powder amount in the same casing, if I understand correctly, similar to a magnum round.
However Match grade hand load is a MUCH more consistent round, thats why mostly sharp shooters and long range weapons use match grade hand load.
These rounds are good for punching through light armor (jacked) and killing whats inside it (hollow point)
HP= hollow point, good for killing soft things. I.E, geckos and dogs, unarmored/light armored humans.
AP= good for killing things that have armor, I.E Death claws, and Power armor.
JSP= Jacked soft point is similar to JHP
SWC= Semi wad cutter. Functions like a JHP round AFAIK.
AP Armor piercing, more armor (DT) mitigation, less damage.
Incendiary, Sets things on fire. .50 only.
12/20 G Slug. A sold shot from a shot gun, considering that 12 gauge is pretty large, thats about like a .50 from a shot gun.
Magnum, more powder, same shot. Longer range + more damage.
Coin shot, Uses coins. (never used before personally)
.308 Hand loaded
.50 Match grade hand load.
Basically a hand load is a higher powder amount in the same casing, if I understand correctly, similar to a magnum round.
However Match grade hand load is a MUCH more consistent round, thats why mostly sharp shooters and long range weapons use match grade hand load.
Buying things. (minor spoiler)
Spoiler
best
188 Trade post.
Gun runners
BOS bunker supply.
NCR
Middle
Good springs
Novac
Bad
Places that don't sell ammo.
188 Trade post.
Gun runners
BOS bunker supply.
NCR
Middle
Good springs
Novac
Bad
Places that don't sell ammo.
Weapon mods that I have found so far, and what they do.
Spoiler
.357 HD cylinder. +50% condition.
.357 long barrel. +3 damage
.44 long barrel + damage
Sniper rifle- Carbon fiber parts. Weights less.
Sniper rifle- Suppressor, Reduces noise and muzzle flash.
Mini Gun-High speed motor- Faster firing.
9MM, Extended mags= More ammo before reloading (20)
9MM scope= a short range scope!
Varmint Rifle, Suppressor
Varmint Rifle, Extended mags
Varmint Rifle, Scope
10MM, Extended mags
Cowboy Repeater, Custom action, shoots faster.
Cowboy Repeater, Maple stock, less weight
Service rifle, upgraded firing pin? fires faster.
.357 HD cylinder. +50% condition.
.357 long barrel. +3 damage
.44 long barrel + damage
Sniper rifle- Carbon fiber parts. Weights less.
Sniper rifle- Suppressor, Reduces noise and muzzle flash.
Mini Gun-High speed motor- Faster firing.
9MM, Extended mags= More ammo before reloading (20)
9MM scope= a short range scope!
Varmint Rifle, Suppressor
Varmint Rifle, Extended mags
Varmint Rifle, Scope
10MM, Extended mags
Cowboy Repeater, Custom action, shoots faster.
Cowboy Repeater, Maple stock, less weight
Service rifle, upgraded firing pin? fires faster.
Thats all I know of, fell free to add to the list.
Other things to consider.
Special/unique weapons CAN NOT be modified.