What capacitor (condenser) do you use?
The capacitor should fit the coil spec.
Think a 0,20-0,25 mikro Farad would be fine.
Have you set the points to 0,014 in (0,35 mm)?
Do you have solid copper core HT wires?
BR7HS-10 has a built in radio suppression resistor and the electrode gap is 0,040 in...