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tinker
.416 member


Reged: 12/03/05
Posts: 4835
Loc: Nevada
Chamber Casting with Cerrosafe - getting useful results
      21/07/08 04:20 AM

Chris-

It looks like you have a fun project in your hands there.
If that action locks up tight on the face, the locks are safe to run, and the barrels don't pop when you get it out for a test drive,
you'll have a really fun hunting rifle that you won't have to worry about getting 'a little nick' in the finish out in the field.

Congratulations to you!

A chamber cast is a great place to start, it can tell you a lot.
Something I always look for is a bulge or ring in the chamber.
Bulge in the belly of the chamber, swollen ring near the neck.
These could indicate previous overloading, shooting with unsafe loads,
or point out previous 'chamber work' like overzealous clean-up of pitting with abrasive stones in power tools (it happens...)
This kind of issue wouldn't show up on the outside of the barrels or chambers if at some time in the past
someone 'struck up' the problem on the outside of the barrels with files and stones during a re-finish job.
That rifle has seen some re-finish jobs in it's career.

Something for you to note, for others to know for further reference, it's pretty easy to get perfect chamber casts.
There are an infinite number of ways to do it wrong, and most of them will give crap results.

No offense meant here, but what you show above is a pretty much useless chamber cast and you need to start fresh.
You also need to slug your bores with pure lead roundball from muzzle ends and chamber ends.

Chamber casts, when done right will give you a huge amount of information on the condition of your chambers,
and the condition of your bores at the leade of the rifling.

You need perfectly clean, dry and warm barrels to do it right.
Clean so that you are not measuring the negative space left where there was dirt or oil.
Warm barrels so that the cold barrels don't solidify the casting alloy as it's being poured.

Look at this path to good chamber casts.
Notice that it doesn't take any more time or effort than doing a bad job, and believe it that it takes this kind of approach to get good results.




First thing.
With cerrosafe, never use a 'release agent'
It is not necessary.
It will give poor results.
Start with fresh, very clean chambers and bores.

Next, Set Up.
When you are setting up to do your chamber casting, get two big pots of water boiling.

One of them is to use as your 'double boiler' heat source for melting the cerrosafe alloy.
DO NOT USE A TIN LINED POT TO MELT YOUR CERROSAFE ALLOY!

The other one is to set your rifle breeches into so as to get them up to (this very low temperature) the same temperature of your casting alloy.

Make sure that whatever tools you will be using, such as ladle and funnel are also up to the same temperature.
Use gloves or pliers or 'vice grips' to handle the tools and the little pot of casting alloy.

Make sure you have a hard wood rod long enough to completely pass through your barrels.
This is what you will use to 'tap out' the chamber cast.
Also, have some nose tissue or toilet tissue and practice stuffing it real hard into the chamber end of your bores.
This is what you can plug them with, and it works great.
Everyone has something like this in their house.
You can use cloth from an old undershirt or bed sheet too.

Have a vise with padded jaws or the back of a chair and some shoestrings or whatever,
to hold your rifle barrels firm, solid, and steady,
chambers up.

Do one or more practice runs of taking the barrels out of the pot,
clamping them with the chambers up,
stuffing your 'bore plugs' into the bores an inch into the rifling past the chambers,
and handling the other tools of the job.
You don't want to fumble when it's time to do the job.

Make a 'catch basket'
Cerrosafe chamber casts can break if they drop onto a hard surface or fall off the table.
Also you don't want to foul up the surfaces of your casts.
Keep all the information about your chambers you can!
Have a nice soft spot to catch the chamber casts.
I have used a cardboard box with crumpled newspaper as padding,
an old undershirt placed on top as a landing pad


Now, Get Ready...
Know how much tissue, or old undershirt or bedsheet fabric you need for your bore plugs and have it ready to go.

Get the chamber ends of your barrels into their pot,
get your 'double boiler' in the other pot and add the casting metal.
Put your other tools in either of the two pots,
I usually hang them from the edge of the pot that the barrels are in.

Give the pots of water heat,
get the water good and hot,
get your alloy flowing in it's 'double boiler'


Now it's time to go!
When the casting alloy is up to temperature, your barrels are ready to take from the water and get secured into the padded vise jaws,
or tied to the back of the chair,
or clamped to a ladder
or whatever.

Plug the bores so that you get an inch or so of the rifled bores.
Clamp the barrels nice and steady.
Make sure your extractors are set into their cuts,
that they are level with the chamber rim.

Carefully pour the cerrosafe alloy into your chambers,
going up to the top of the rims 'and a little bit more'
Ideal shape is kind of like a mushroom cap.

Note the time on your clock and wait 30 minutes.
When 30 minutes pass, get the barrels out of the vise or whatever,
and carefully turn them over to drop the casts out into your padded 'catch basket',
if they don't drop out, the wood dowel with a light tap from your hand should drop them out.

Follow the directions that came with it (and are available on the web) for measuring what you get.


As well as chamber casting, it's also important to slug your bores with pure lead roundball.
Go from the chamber end, go from the muzzle end BOTH WAYS.
The bore slugging process will give you good indication of your bore/groove dimensions
and will also give you a good sense of whether or not there are bulges in your barrels
(indicated by parts of the barrel that 'get easy to push' the slug through)
and will also indicate such other things as gain twist rifling or tapered bores.

Not to say we expect to see any of that in this rifle,
but someone in the future will find this post in a search, and their rifle might...



--Tinker

--------------------
--Self-Appointed Colonel, DRSS--



"It IS a dangerous game, and so named for a reason, and you can't play from the keyboard. " --Some Old Texan...

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Entire topic
Subject Posted by Posted on
* Identifying a chambering -Thomas Turner BP double ChrisPer 21/07/08 02:09 AM
. * * Re: Identifying a chambering -Thomas Turner BP double miroflex   31/07/14 12:28 AM
. * * Re: Identifying a chambering -Thomas Turner BP double Huvius   31/07/14 01:04 AM
. * * Re: Identifying a chambering -Thomas Turner BP double kuduae   31/07/14 02:03 AM
. * * Re: Identifying a chambering -Thomas Turner BP double Huvius   31/07/14 03:54 AM
. * * Re: Identifying a chambering -Thomas Turner BP double kuduae   31/07/14 05:56 AM
. * * Re: Identifying a chambering -Thomas Turner BP double Huvius   31/07/14 11:07 AM
. * * Re: Identifying a chambering -Thomas Turner BP double kuduae   31/07/14 07:57 PM
. * * Re: Identifying a chambering -Thomas Turner BP double ChrisPer   07/08/14 09:06 PM
. * * Re: Identifying a chambering -Thomas Turner BP double 400NitroExpress   21/07/08 01:35 PM
. * * Re: Identifying a chambering -Thomas Turner BP double ChrisPer   21/07/08 01:58 PM
. * * Re: Identifying a chambering -Thomas Turner BP double ChrisPer   24/07/08 08:17 PM
. * * Chamber Casting with Cerrosafe - getting useful results tinker   21/07/08 04:20 AM
. * * Re: Chamber Casting with Cerrosafe - getting useful results NitroXAdministrator   09/06/22 06:20 PM
. * * Re: Chamber Casting with Cerrosafe - getting useful results NitroXAdministrator   09/06/22 10:04 PM
. * * Re: Identifying a chambering -Thomas Turner BP double ChrisPer   21/07/08 02:15 AM
. * * Re: Identifying a chambering -Thomas Turner BP double lancaster   21/07/08 02:31 AM
. * * Re: Identifying a chambering -Thomas Turner BP double AkMike   21/07/08 04:02 AM

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