You should be driving the base of the 2N3055 with at least 120mA (Ic/10). This means the base resistor should be about 75 ohms, unless you are using a CMOS 555, which can't source 120mA, so you would need to switch to a bipolar 555 before proceeding.
You also need some capacitors from Vcc to ground, with short leads, as close to pins 1 and 8 as possible. I would use a 100nF (0.1uF) ceramic cap in parallel with an electrolytic, 100uF or so.
If you want to create a fixed length pulse, you need an RC timing network.
Where did you get this schematic?