If you are one point off your ult and the only orb around is the weapon upgrade orb, you can drop your current gun and then consume the orb. That way you'll have both guns and can pick whichever one you want. Same goes for the golden gun...

Can we exchange some advice about how to best perform in solo queue, especially in lower ranks? Personally I'm Gold 1 now and I'm still kind of afraid of solo queuing due to just how volatile it can be compared to playing with friends....