MAKING A SILICONE GLOVE MOLD OK, I didn't get any pictures of a few steps at the beginning.  I didn't plan on making a tutorial for this, sorry.  Basically, I laid the gun on the foam, traced the outline, and cut inside that line 1/4-1/2".  I then laid the gun into that hole and used clay to seal around it.  If it's not your gun make sure you have an OK from the owner and do a small test someplace that can easily be refinished should something react with the finish on the gun.  I used sculpey since I had a lot sitting around. You want the gun to sit halfway in the foam, directly down the centerline of the gun.  You also want to get the clay as smooth as possible, this will minimize the seam on the castings.  (Do I even need to explain basic gun safety?    Also, make sure to wipe down any grease, oil, or dirt. When finished with the mold, clean EVERYTHING OFF then clean it like you had just gone shooting, or return it to the owner immediately and have them do it.  If you're not molding a gun, disregard that, but the gun safety rules are always a good thing to know and to teach kids.) After that, I made a gutter key using a clay gun, that extrudes the clay into a 1/2 circle shape. You want this to remain at a fixed distance from the gun all the way around it, 1/8-1/4" is good.  I also added vent and pour holes in the bottom of the grip and the rear of the stock using glue sticks.

Here's another angle, showing the glue sticks and the end of the gutter key to give an idea of the placement.  Below when the mold is flipped you'll be able to see things a little better one what happened on this side of the mold.  In this picture I have brushed a layer of fast catalyzed silicone on. At that point I mixed silicone according to the instructions and added cab-o-sil, a very lightweight (and easily airborne, wear a mask!) powdered glass basically.  This was added a little at a time until the silicone was the consistency of peanut butter, a thick paste.  You want it thick so it doesn't seep into the gun, but you want it to slightly sag so that any air bubbles on the surface will be eliminated.  I then spread it on trying to eliminate any air bubbles The silicone I used on this was GI-1000, a general low cost silicone, but it's life can be limited. That about brings us up to date.

OK, the fiberglass is on.  Before I started the fiberglass I glued several silicone keys down onto the foam that serve to line up the shell in the correct position.  I first mixed up a batch of polyester resin and baby powder to a thick paste, then spread it on.  I let it set slightly, and added fiberglass mat torn into small squares. Never cut mat, tear it.  I also should mention that the foam had a plastic film on it that I left in place.  This film prevented the resin from eating away at the foam.  Besides the film I sprayed on PVA (polyvinyl acetate) which is used as a fiberglass mold release. It forms a thin film that is water soluble and aides in separating fiberglass from itself. I added a couple layers of mat.  I should have used more layers and thickened the edges for when I bolted it together.

This is the first half of the mold finished and removed from the foam.  You can see the rough edge of the fiberglass.

OK, here you can see the gutter key and vent and pour holes better here since I labeled them.

Besides the gutter key, this picture illustrates the negative key.  The green color is due to the PVA but the color does vary from manufacturer to manufacturer.  It's best applied with an airbrush or paint sprayer in light coats.

Another picture of the first half of the mold.  You can see the marker line that I drew on the foam to show where to trim the fiberglass when done. Also the green PVA is visible.  This was before removing the gutter key and clay.

Here the clay has been removed and the gun cleaned.  The silicone has been given a thin Vaseline layer to prevent the next side of the mold from bonding to it.  Silicone WILL stick to itself if this is not done.  You only need a little.  Make sure to get all of the silicone then double check. The serial number has been taped over. If you look you can see that some silicone has leaked by the trigger and sights.  I carefully trimmed this with an Xacto blade, don't damage the gun.

All ready for the next half of the mold.  I will again mix up the silicone, catalyst, and cab-o-sil to paste consistency and apply as before.  I try to keep the silicone the same size as this half.  Also, you want the silicone to be smooth on the outside, but you do want some keys on it. They'll help to keep it in the jacket..

Here both halves of the silicone are done.  I added silicone keys here to use as pry points so I could get my fingers in to open the mold.  I also spray PVA on the fiberglass again, follow the directions.

This is the first layer of fiberglass, polyester resin mixed with baby powder to get a smooth surface on the inside of the mold.  This layer prevents any of the mat texture "printing through" into the mold.  This could cause problems if any of the casting resin leaks out of the seam and bonds to the mold.

The mold is almost done.  I have to trim using a dremel (wear a mask, gloves, long sleeves, and glasses, then do it outside. Plan on being itchy anyway.)  Drill holes before separating the halves. These will be used to bolt the mold together for casting and storage. I believe I used 12 on this, but a few more wouldn't be bad.

The mold opened, cleaned out and ready to close up and cast in. The large silicone can be floppy, so I assemble the silicone, then wiggle the fiberglass into place and bolt it together.

Here the first casting is done, it was a combination of polyester resin (the same type used to make the shell of the mold) and bondo.  The tan/brown color by the barrel is where the bondo/polyester resin mix has leaked out the seam. If casting this material in a mold like this, use PVA on the fiberglass first.  This will prevent it sticking and ruining the mold.

A close up of the pistol grip area.

A casting of bondo/PE resin. The detail areas were cast with polyester resin to get the nooks and crannies.

A casting of bondo/PE resin. The detail areas were cast with polyester resin to get the nooks and crannies.

The first casting trimmed, sanded and patched up ready for paint.

Finished.  Even thought they're referred to as EBR (evil black rifles) they're not really black. The actual gun is an anodized aluminum and can vary slightly from a deep gray, that is almost black, to much lighter tones. This one was painted a little lighter then the one used for the mold. However, the magazine is about dead on.

My neighbors think I'm nuts, glad they didn't call the cops.  The PVC suppressor was added to cover up a bad casting on the barrel.  It's a little thin and long, but gets the point across. It was attached with some Bondo body filler.

This is probably the second easiest way to mold a rifle, the first would be a box mold with a support shell like the grappling hook gun page here.  The box mold method will be more expensive due to the large amount of silicone needed.   Another method would be that laid out here.  The case mold.  It's a bit more involved, but materials are kept to a minimum.  Oil or wax based clay could be used to avoid any rust issues on a real gun.  The stone support shell would be replaced with fiberglass.  If I were going to do another rifle mold I would probably strongly consider the case mold due to cost.  But with a short deadline a glove mold is a good compromise.