Shear force result - pin vs bolt connector

[JScad]

Hi all,
I have run a comparison analysis on a bolted connection with two plates in shear. The first used bolts with tight fit, the second used pins. Comparing the connector results, the pin shear is about 43% higher than the bolts in this analysis. I've noticed also than on a magnified (20x) displacement scale there is slight relative movement between the plates in the bolted connection, whereas there is none in the pinned. I can only guess that the bolt formulation is different to the pinned formulation and therefore allows this movement. Any ideas?