Chamber Casting

[BigGreen2000]

Hello! I need to do a chamber casting on my rifle. What material do you all use? Low-melting metal alloy? Wax? Any tips?

[Jedman]

Cerosafe, it is a metal that melts at low temperature. Follow instructions as it can get stuck otherwise.

Jedman

[RustyReel]

Cerosafe, it is a metal that melts at low temperature. Follow instructions as it can get stuck otherwise.

Jedman

Don't panic if it does get stuck. Because of the low melting point you can easily melt it out. Also, it can be reused so hang onto it.

[LAGS]

What type of rifle are you doing the chamber casting on ?
Some rifle have Querks that can make the casting more difficult.
But if you know what to watch out for , then there are no issues.

[Moleman-]

For cerrosafe basically think in terms of boiling water, it just has to handle boiling water temps for a short while. If there's something you need to block off, like the barrel extension on an ar15/10 or something similar I just block off those areas with plumbers putty.

[BigGreen2000]

Chamber on a mil-surp bolt action rifle

[LAGS]

Most of the Mil Surps all cast the same way and are really easy as long as you don't overfill the chamber and lock the back of the casting into the recess for the bolt lugs.
To plug off the barrel,
I use a 1/4" brass rod inserted from the muzzle with a cleaning patch over the end of the rod to fit snug down the bore. ( Like a cleaning operation )
I run the rod down the barrel and stop about an inch from the end of the chamber.
I tape the protruding rod to the muzzle to keep it in place while I am casting the chamber.
Then once the chamber is cast , you have the rod in place to tap the casting out of the chamber.
Several people have brought me rifles that they just wadded up balls of patch material stuffed down the barrel at the end of the chamber.
The pillow effect of the patch material then ended up causing a cushion that would not let them drive the casting back out of the chamber.
The brass rod with a patch over the end acts as a Seal and then is only a thin piece of fabric that doesn't act like a shock absorber when you tap out the casting.
The rougher the chamber , the harder it is to drive out the casting and those can be common in old Mil Surps.

[MOA]

I second what LAGS said. If your chamber is very rough or pitted the casting can become locked in place by the material flowing into the divot like surface in your bore. Don't ask how I know. 😆

[LAGS]

If the casting gets stuck in the chamber.
I just heat up the chamber area with a heat gun gently.
It will soften the Cerosafe enough for it to shear off the bumps that cast into the divots.
The casting can then be driven out and be mostly intact.
The imperfections can still be seen on the casting.
And if the casting is Stuck too bad , I just heat up the chamber area long enough to remelt the Cerosafe and pour it out so you can start over.
Epoxy or bedding material can work for casting chambers if you put release agent in the chamber.
But it better be a Smooth Chamber.
If it is rough , I will get stuck and can not be pounded out.
I have done a few New Chambers with Epoxy so I had a casting that I could save for future reference so I don't have to use up lots of Cerosafe and just have usable material going to waste just sitting around.

[Cap'n Morgan]

I make chamber casts using paraffin wax from melted candles. Just plug the barrel with a tuft of paper and pour in the stuff. Although paraffin will shrink considerably, it will quickly solidify from the outside and then shrink the center. If you insert a suitable wood screw while the core is still soft, you'll have a nice handle on the cast. Be careful when heating the paraffin, don't force the process (and don't ask how I know)

[rboeser]

Mount the barrel or rifle straight up in a vise with a barrel block so you don't ding it up. Use a brass or hardwood dowel with a single layer of cleaning patch as said before. I stop around 1/2" short of the lands so you get a short length to measure the bore and even some rifling. Be sure to clean the chamber well, then a light wipe with gun oil to the chamber to act as a release agent. Use Cerosafe as stated. After cast use the dowel to lightly push the casting out. Good thing with Cerosafe is it only shrinks about .0005 to .001 if memory serves me.