Is there any reason not to make a chamber cast of my rifle using Cerrosafe?

Nope. It works well.

Directions state to preheat chambers (hot air gun) or does not cast properly. I recommend ensure chambers interior waxed and/or oiled or may get cerrosafe casts stuck like mine did (followed directions and timelines- stuck anyways). I had to boil breech end in soup can over hot plate to remove cerrosafe as casts would not pound out for love nor money even within contraction/expansion timelines (see directions). Chambers need to be hot enough so cerrosafe doesn't solidify too soon, but not too hot or you might experience same. First cast solidified too fast: not a full cast. second casting lacked oil present on chamber walls for first cast and the second (better preheated) casts filled every pore and stuck solid when it solidified. Good luck.

Fantastic stuff.......a MUST HAVE in any good gunsmithing shop.

I quickly cast every chamber I cut just so I can be 100% sure there are no issues that are obvious.

I do not heat up the barrels but pour at room temp. I run a cleaning patch in the area I want to cast with some light oil on it. Never had a slug stick.

Stick a piece of paper towel down the bore an inch past the chambers neck. Heat up the Cerrosafe in a ladle with a heat gun and pour it in. Wait a minute or two and use a cleaning rod to pop it out.

If you are taking measurements, wait about 15 minutes for the material to swell back to the proper size.

When done, reheat (melt) and store.

I made this little ladle that I store my Cerrosafe in.

I need to do a bolt action. How do you pour it in? Do you make some kind of funnel?

I'd form a funnel out of tin-foil for a bolt gun.

I've used in many many times, i just hold the metal UP over the open flame of my gas stove, and pour into the chamber.

GREAT stuff to see what you REALLY have for a chamber and leade...

DM

Break-open guns with extractors/ejectors are susceptible to the cast being locked in the chamber if even a small amount of cerrosafe gets under the extractor. Likewise bolt guns if too much is poured and fills the lug recesses. If this happens, remove any wood/ plastic close to the chamber and heat this area gently with the muzzle up until the "lock" melts and the cast falls free.

Plug the barrel from the muzzle with a patched brush to within an inch of the chamber neck(as previously mentioned) and knock the cast out of the chamber soon after it "freezes". Done this way, you don't need to oil to get release--even with virtually straight revolver chambers.

DManson