The slings used by both Muldoon in the end of the movie are both certainly black. It's a topic of contention, at least for a few Project members, as to if Muldoon's sling at the begininng of the film is dark green or black. the same as sam neil does and quote they move in herds, they do move in herds. Another reason is it's possible that, due to their known fragility, the top sling mount (swivel drum) was not used for fear of breaking. Check out Welcome To Jurassic Park by John Williams on Amazon Music.

One reason being that when using the top sling mount (the swivel drum mount on top of the pistol grip) the range of motion of the stock is encumbered, and Muldoon wouldn't be able to deploy the stock as he so famously does. This could have been done for several reasons. They are also strangely clipped on to the holes of the folding stock. And a new study shows that the prehistoric creatures lived in herds much earlier than previously thought.

It is unsure what exact slings they were, but that is probably because they are very generic in appearance. To borrow a line from the movie 'Jurassic Park:' Dinosaurs do move in herds.

The slings in the movie are not Franchi factory slings. The good news for you JP fans with a budget is not only that SPAS 12's with lever safeties are generally less expensive, but you also don't have to worry about finding two fairly rare accessories to be 'screen accurate', the factory hook/arm rest, and the factory sling.