Chamber Cast Options

[GregLaROCHE]

I haven’t done a chamber cast before, but I am planning to do so soon. I’ve read about different methods including lead pound cast, Cerrosafe, melted sulfur, hot glue and melted crayons. Has anyone ever used plaster of Paris. I’m not particularly tinkering about it, just wondering if it is an option. I’m leaning towards a pound cast, but am open to other ways. The shrinking of Cerrosafe and having to apply corrections to measurements, that I understand keep changing with time, makes it seem much more complicated. Otherwise, I think I would try it.

What experiences have others had in chamber casting and with what mediums, along with their pros and cons. All advice appreciated.

Thanks

[NoZombies]

Do NOT use plaster of Paris. It has too much potential to create issues down the road.

If you're trying to confirm a chambering, then most methods will work, if you're looking for very precise dimensions of the chamber, then cerrosafe is about the only really good option in my mind. The shrinkage and growth aren't as big a deal as it's made out to be. The shrinkage makes removal easier, just pour, wait 30 minutes to remove, and measure an hour after the cast to get basically perfect dimensions. Honestly the shrinkage and growth are a smaller variation than is normally caused by poor measuring tool usage.

[GregLaROCHE]

What’s the best thing to use to plug the bore when using Cerrosafe?

[KCSO]

Sulphur works well if you get the shrinkage chart.

[22cf45]

Cerrosafe is all I will use. No muss, no fuss.
Phil

[John Boy]

Use a cotton ball to plug the bore

[LAGS]

A cotton ball will stop the Cerosafe.
But it can also act like a Pillow and cushion you ramrod so much that you can not drive the casting out of the chamber.
In school , they called it "Over Ragging The Barrel"

[MarkW]

I've used sulphur with good luck. I take kleenex or paper towel and roll it up into a pea and push it into the bore about 3/8" or so, enough to get past the throat and into the rifling. For melting the sulphur I cut a pop can into a ladle, I cut around the bottom and leave about an inch but don't cut all the way around, have the cut stop to give you about an inch of uncut area. Now cut from the top down and then you can use that piece as a handle for your ladle (hope that makes sense!). I also put some oil on a swab and give the chamber a light pass which helps the cast to get driven out.