The damage output has now been severely upgraded (to a staggering 63.5k per shot). 38 seperate crafted triple railguns mounted on it puncture shields with a 30% chance to bypass completely, at a range of around 7kms.
However, even at 4k damage, as railguns damage all items they pass through in a straight line (with the exception of armor), this means 4k is applied to EVERYTHING they touch, and usually ignores shields completely. So, it will quite literally crack a ship in half with one shot, even with the lower damage output.
The pictured interceptor now also sits around 10k damage output, and it's about 1/50th the size of the capital.