Sydney's 10mm "Ultra" SMG

Sydney's 10mm "Ultra" SMG is a unique small gun in Fallout 3.

Characteristics
Sydney's Ultra SMG is more powerful than regular SMG's, doing 9 damage per discharge rather than 7. It also holds an extra 20 rounds per magazine. This puts it in the same basic place as the MP9 10mm SMG in Fallout and Fallout 2; Sydney's Ultra makes the N99 10mm pistol obsolete.

Technically, Sydney has two versions of this weapon. According to the GECK, she carries a non-playable version, and a playable version is spawned on her person when she is killed, as a "deathitem". (As a companion, she will use up ammo for any non-companion weapon, so the non-playable version exists to prevent this.) Thus, if she dies and you take her weapon, you may notice that she appears to still be holding it in her hand.

Location
Sydney the relic hunter carries this weapon. It can be obtained by either killing her, letting her die, or finishing the quest Stealing Independence and giving her "A Note from Little Moonbeam's Father".

Bugs
There is a exploit in all versions of Fallout 3 that allows you to receive unlimited copies of her Ultra SMG in perfect condition, along with 50 10mm rounds. To trigger the exploit, after receiving the gun once choose the following dialogue options:

"Since we're done now, why don't you tell me about yourself?"

"Nice gun. I've never seen one like that." (she mentions her father and re-triggers the option to ask about him)

"That's all for now, I guess" (taking you back one step in the dialogue tree)

"So, whatever happened to your father?"

and finally, "Sydney, I found a note from your father. He didn't abandon you."

You should then receive the Ultra SMG and ammo again. The above steps can be repeated as many times as you want for a limitless supply of both the gun and 10mm ammo. You can also exit the dialogue and come back to repeat it again at a later time.

Videos
Video:Fallout 3 Sydney's 10mm Ultra SMG &amp; quest

10-мм ПП Ультра Сидни