I disassembled both weapons, laying aside the unneeded parts. Then,
claying the openings that would cause problems with making the mold,
I proceeded to clay line each incorporated gun component into mold boxes,
and then cast RTV molds around these parts.
Once the molds were cured, many sacrificial castings had to be made
to use as working prototypes. I knew that quite a few would have
to be cut up while working out all the fit and features we wanted.
We know that the original Steyr bolt could not have been used in the
hero prop by the fact that what can be seen though the ejector port
of the gun and what shows up in the stunt castings has none of the features
of the real part. Neither the shell extractor arm nor the two
small holes in the Steyr part are present. Instead, the stunt
prop bolt has a long groove machined into it, which is not a feature
of the Steyr or any other bolt, but makes for nice decoration.
First I turned out a couple of test bolts using Delrin ®
in order to get the right fit and work out details.
Working with a softer plastic made for faster cutting and sanding.
Then I began
machining a slot in the
underside of my new bolt to allow clearance for the Bulldog’s frame.
I tried to use the locking lugs of the real Steyr bolt locking system
but found that the molds could not handle the severe undercuts of the
inside bore of the Steyr receiver. Regardless, when I determined
how much would have to be removed from both the bolt and the locking
lugs, I found there would be so little left that preserving the feature
was of little practical value.
Once I lined up the Steyr receiver with the Bulldog over the stunt
prop, I could see that, for the Bulldog barrel to line up with the centerline
of the stunt prop barrel, the Bulldog would have to cut about halfway
into the centerline of the Steyr receiver and bolt!
Ideally, the blaster model would have a working bolt with cocking
lever action. We could discern that, at the very least, the cocking
lever was able to move some on the hero prop, for it can clearly be
seen to swing out in the film scene where Deckard drops it onto
the street while being chased by Batty.
At this point during the project, we had not yet located the original
propmaker to confirm the functionality of the bolt. Either way,
I believe it makes for a much more realistic model to have various working
components, and the bolt action is one of the truly prominent features
of this fabulous weapon.