Chamber cast?

[LIMPINGJ]

I need to make a chamber cast but do not want to wait till next week for the lil brown Santa truck to bring some Cerrsafe. In Dunlap's book he says use sulfur and graphite. What purpose do the graphit serve in this mix? Could I just use sulfur or do I need to make a trip to town and check the auto parts store.

[gnoahhh]

Wait for the UPS truck. Sulfur casts a) will stink up the house and b) have a weird expansion/contraction rate as it cools and ages and c) are more fragile than a Cerrosafe casting. Accurate reading of them requires some practice too and simply don't give the readings even a newbie can get with his first time with Cerrosafe.

If you go ahead with the sulfur cast follow whatever directions you have to the letter, especially if they tell you to wait X hours after casting before taking measurements. I have no idea what purpose the graphite serves. Maybe a built in lube to ease removal from the chamber?

I knew an old gunsmith who routinely did sulfur casts and the moment he tried Cerrosafe he never looked back.

[DAFzipper]

This works well for me.
http://castboolits.gunloads.com/showthread.php?t=53958


I did my 30/06 chamber also.

[Good Cheer]

Sometimes when I'm just after length info like what the case mouth to rifling looks like, I use a longer case necked and annealed to blow into the chamber. Like make a 25-08 out of a 30-06 and fire form it into all the nooks and crannies of a 7-08 or 308. However, you probably cannot get any kind of realistic diameters info no matter how well you anneal the brass or how hot the forming is loaded.

[Good Cheer]

Here's one.
http://i791.photobucket.com/albums/yy192/SNARGLEFLERK/762chambergage.jpg

[mroliver77]

If you are looking for case length and neck/ball seat area + throat do an impression by upsetting soft lead in a shortened case. Gives exact measurments and impression can be saved forever.
Jay