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  Chamber Casting Alloy Ingot

Base Price: $15.99

Availability:: in stock

Sold by the ingot. Ingot weighs approximately 1 pound.

Rotometals Chamber Alloy (158-190) is the best known material from which to make a casting of the chamber and throat of a firearm to determine caliber or check the dimensions. It melts at a temperature just above M & M's, so all you need is a propane torch and a bullet casting ladle. It can also be used to make a cast of a dovetail slot or any other hard to measure area. Also, it is great for removing the front half of a case from the chamber, in the event of case head separation; and lots of folks cast a small portion of the barrel to determine bore diameter. For best results, measure the casting one hour after casting. Contains 42.5% Bismuth, 8.5% cadmium, 37.7% lead, 11.3% Tin.

Technical Information

Basic Instructions
  • Plug the bore immediately ahead of the throat of the chamber using a small cleaning patch.
  • Pour the alloy directly into the chamber until full and allow Melting Point to cool, it will turn a shiny silver color. As soon as it has cooled enough that it is no longer a liquid (and doesn't present a burn hazard), remove it from the chamber. Take care not to overfill the chamber as the alloy will then run into the locking lug area, making removal extremely difficult.
  • During the first 30 minutes of cooling cerrosafe shrinks. At the end of one hour it should be "exactly" chamber size.

  • Melts between 158 and 190 degrees Fahrenheit
  • Should be melted in a clean iron ladle without direct flame on the product.
  • The chamber being cast should be cleaned thoroughly and a thin coat of oil or graphite applied.
  • Reusable

    Contraction expansion factor versus time, measured in inch per inch compared to cold mold dimensions. Test Bar x 10
  • 2 minutes - .0004"
  • 6 minutes - .0007"
  • 30 minutes - .0009"
  • 1 hour + .0000"
  • 2 hours + .0016"
  • 5 hours + .0018"
  • 7 hours + .0019"
  • 10 hours + .0019"
  • 24 hours + .0022"
  • 96 hours + .0025"
  • 200 hours + .0025"
  • 500 hours + .0025"

  • Average Customer Review: 5 of 5 | Total Reviews: 1 Write a review.

      8 of 9 people found the following review helpful:
    chamber casting December 26, 2009
    Reviewer: Terry Salyer from Pedro, OH United States  
    At eleven dollars a pound you can afford to make a chamber and bore casting of all your weapons and keep it on file. If you're reloading you need to know what your exact bore size is,the amount of free bore,and exactly what your chamber looks like. On revolvers you need to know what each hole measures as they differ just as bores differ. The last chamber casting alloy I got from Brownells cost me almost fifty dollars. With this stuff at eleven dollars a pound there will always be a few friends who want to borrow it and you never get it all back. I recommend it because the price is right enough to keep the castings and not remelt.

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