Chamber casting tricks

[1Hawkeye]

I want to find out the exact chamber depth of my .38-55 c.sharps 75 as both starline case lengths fit when I made dummy rounds. My thinking is to milk out all the accuracy possible but I don't know if I should get some longer cases till I find out the depth. Here's the thing I don't have any cerrosave so can parafin wax be used for the purpose?

[toallmy]

A pound cast will give you the information your looking for , with a fired case and some soft lead .

[Wayne Smith]

For just length of the chamber almost anything you can get out whole will work.

[Texas by God]

Paraffin will absolutely work and very easy to do on a Sharps. Lightly oil the chamber and put a toilet paper plug about 3" from the breech block in the barrel. Fill it to the rim recess, let it cool and push it out with a cleaning rod.

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[LAGS]

I have used Epoxy to cast some chambers.
I tried Wax , but found it distorted when it was pounded out.
If the wax casting just Fell out , it looked like it had shrunk a bit and was not a true representation of chamber dimensions.
Try casting Wax Boolits in your Boolits mold and you will see how much the wax actually shrinks.
Most Epoxy will cast reasonably close to true dimensions and is durable enough to save for future reference.
But by far , Cerosafe is the easiest and IMO , the best, and a lead Pound Cast is second.

[contender1]

At $15 for 1/2 lb Cerrosafe,, it's WORTH the expense of getting some to get a true reading of measurement.

[1Hawkeye]

Well the cerrosafe is on its way. I found some on evilbay for 20.00 a pound freight included so now I can take my time and do it correctly.

[KCSO]

Use powdered sulphur from the drug store, Dixie has a shringage chart if you wat to be down to the last 1/2 thousand. Oil the bore and melt the sulphur in a spoon and pour it in. Fragile when tapped out don't drop it>

[LAGS]

To do my chamber casting.
I take a Brass or Aluminium rod about 3 feet long.
I insert it into the muzzle with a single cleaning patch placed over the end of the rod like on a cleaning jag.
I run the patch into the bore all the way up to just about the end of the rifling at the freebore.
I Leave the rod and patch in the barrel , and tape the rod to the muzzle.
The patch and rod seal off the barrel , and are easier to drive the casting out because the single layer of patch is not acting like a Pillow between the rod and the end of the rod.
Several people have brought me their barrels because their casting was stuck in the chamber because they Over Patched the barrel.
The thickness of the ball of patches was acting as a cushion , and wouldn't allow the drive out rod to exert enough force to drive out the casting.

[Texas by God]

As you know, .375"=3/8". With your Sharps, perhaps with a gingerly inserted base of a 3/8" drill bit you can feel the chamber end. Or the rifling orgin and measure accordingly. Just guessing; I cant try it in my Win94 38-55.https://uploads.tapatalk-cdn.com/20200826/e27e9598d909cb9e8d4d963c47c9d4cc.jpg

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[LAGS]

That could work to find Some Measurements.
But I would Opt to use a 3/8" Brass Rod instead of a Steel drill bit.
You don't want to leave any marks in the rifling or forcing cone.

[ascast]

Well the cerrosafe is on its way. I found some on evilbay for 20.00 a pound freight included so now I can take my time and do it correctly.

Take very thorough notes. perhaps a picture or two. Get an inch of rifling or so as well. Also good for muzzle cast and can revel crowning issues you may not see with eye. Also useful in finding hangups in molds. Make sure you dont mix in with lead. might want to get a separate ladle or spoon. have fun

[Texas by God]

That could work to find Some Measurements.
But I would Opt to use a 3/8" Brass Rod instead of a Steel drill bit.
You don't want to leave any marks in the rifling or forcing cone.
Even better brass, but I did say gingerly........

[1Hawkeye]

Well the cerrosafe showed up and boy is that stuff fun to play with. I was up late casting chambers now to compare castings to sammi chamber drawings while hoping I don't find out anything bad. Thanks for the advise folks.