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Discussion Starter · #1 ·
I've been reading articles about slugging rifle barrels and using Cerrosafe to form a cast of gun chambers. Apparently determining the exact barrel diameter and chamber dimensions helps improve accuracy.

I am a little concerned about doing either process. I wonder if it’s common to get the lead stuck in the barrel?

A friend of mine got the Cerrosafe mold stuck in his gun’s chamber. He got it out but was reluctant to use the process again.

Steve
 

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Cerrosafe is shrinks during the first half hour, then expands back to the exact size after an hour. Then over time, it expands a bit further. You have to factor that in if you want measurements. I suspect your friend left it in too long (ie past the first half hour). From Brownells:

Cerrosafe shrinks during the first 30 minutes of cooling and then at the end of an hour, is EXACTLY chamber size. At the end of 200 hours it will have expanded approximately .0025". This factor is well known by all toolmakers and they will take it into consideration when making dies or reamers or gauges from your cast - if you will tell them the cast is of Cerrosafe.​

Slugging with a piece of sinker lead is pretty easy. Even easier if you size it first to a bit over the barrel. That way the barrel isn't doing all of the forming of the lead (just the final forming). I found that pure lead roundballs work well also. I squeeze them in a vise first, then run them through a sizing die. Pound them through with a close fitting dowel.
 

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I've done cerrosafe 3 times .
1st time tried cast a mauser chamber I failed horribly at that attempt, took about an hour tryng to get it all out of the locking lugs
2nd time was a stripped ar15 barrel that went a lot better.
3rd was gen5 g17 barrel that was a breeze.
My advice would be to preheat the barrel a little so the cerrosafe doesn't instantly freeze up, doesn't take much I can still touch the barrel with out burning my self.
Poring it through a reciver is what as been killing me .
 

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When my dad and i used cerrosafe in our Contenders we stuffed cootton balls down the barrel past the throat and into the lands. Then we stood barrels up and poured to the top of chamber,let cool and measured.Everything came out fine. Good luck on your project.
 

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Before you slug your barrel, make sure it is
very clean, then lube the inside of the barrel
before you start the slug.

You can learn a lot from slugging your barrel.

If you are doing it to better fit cast boolits, you
need to slug the free bore too, and if a revolver,
the cylinder throats, if there is a constriction over
the threads on a revolver it will never shoot its
best until it is lapped out.

There is more to it than just finding out what your
grove dia is.
 

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Discussion Starter · #10 ·
Before you slug your barrel, make sure it is
very clean, then lube the inside of the barrel
before you start the slug.

You can learn a lot from slugging your barrel.

If you are doing it to better fit cast boolits, you
need to slug the free bore too, and if a revolver,
the cylinder throats, if there is a constriction over
the threads on a revolver it will never shoot its
best until it is lapped out.

There is more to it than just finding out what your
grove dia is.
Thanks for all the details!

I’m going over to a gunsmith friend’s shop to do the work on two rifles. When I mentioned slugging the barrels and Cerrosafing their chambers, he said it’s better to slug the barrels from their chambers, in the direction a bullet would have traveled. He said he’s used the Cerrosafe product and commented timing is very important to prevent it sticking inside the chamber.

I will take notes from the post in this thread for review.

Steve
 

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Thanks for all the details!

I’m going over to a gunsmith friend’s shop to do the work on two rifles. When I mentioned slugging the barrels and Cerrosafing their chambers, he said it’s better to slug the barrels from their chambers, in the direction a bullet would have traveled. He said he’s used the Cerrosafe product and commented timing is very important to prevent it sticking inside the chamber.

I will take notes from the post in this thread for review.

Steve
Are you doing this to shoot cast boolits better?

What kind of gun and caliber is it?
 

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I've been reading articles about slugging rifle barrels and using Cerrosafe to form a cast of gun chambers. Apparently determining the exact barrel diameter and chamber dimensions helps improve accuracy.

I am a little concerned about doing either process. I wonder if it’s common to get the lead stuck in the barrel?

A friend of mine got the Cerrosafe mold stuck in his gun’s chamber. He got it out but was reluctant to use the process again.

Steve
A much simpler procedure seems to be measuring the max OAL for your chamber and using brass fired in that gun and neck sized. I don't see what benefit you will get from having a cast of the chamber and bore.
 
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A much simpler procedure seems to be measuring the max OAL for your chamber and using brass fired in that gun and neck sized. I don't see what benefit you will get from having a cast of the chamber and bore.
It's not just knowing what your bore dia is, it's also knowing
if your bore is tapered, is it tapered with the big end at the
muzzle or just in front of the chamber, has tight or loose spots.
Is it consistent all the way through, very good.

A taper with the big end at the chamber end is not so bad, if
the big end is at the muzzle, very bad. Some companies
taper their barrels on purpose.

I like the very soft lead for slugging the barrel, have done
more than I can remember, over 200.???

I have had 9mms with grove dia from .3442'' to .3595'',
what do you thing would be the best size cast boolit for
that .3595'' barrel? will the chamber allow you to use a
boolit that big? How about jacketed bullets, what would
be best for that big barrel?

Slugging can sometimes let you know if the barrel is worth
fixing or if you need a new barrel.

Is the chamber out of line with the barrel? That will not shoot
its best, many times you can see that out of alignment by
just looking.

Yes, I can think of many reasons why I would like to know
about the inside of my barrels, but then I expect much
more from my guns than most, so did my customers.
 

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It's not just knowing what your bore dia is, it's also knowing
if your bore is tapered, is it tapered with the big end at the
muzzle or just in front of the chamber, has tight or loose spots.
Is it consistent all the way through, very good.

A taper with the big end at the chamber end is not so bad, if
the big end is at the muzzle, very bad. Some companies
taper their barrels on purpose.

I like the very soft lead for slugging the barrel, have done
more than I can remember, over 200.???

I have had 9mms with grove dia from .3442'' to .3595'',
what do you thing would be the best size cast boolit for
that .3595'' barrel? will the chamber allow you to use a
boolit that big? How about jacketed bullets, what would
be best for that big barrel?

Slugging can sometimes let you know if the barrel is worth
fixing or if you need a new barrel.

Is the chamber out of line with the barrel? That will not shoot
its best, many times you can see that out of alignment by
just looking.

Yes, I can think of many reasons why I would like to know
about the inside of my barrels, but then I expect much
more from my guns than most, so did my customers.
So the OP talked about "improv[ing] accuracy" and you are talking about determining whether to keep the rifle or not.

As I said, much simpler to just determine his max OAL and use some fired brass and see how his accuracy is. If it's so bad he needs a bigger bullet, which probably means cast lead, he's out of luck and needs to dump the rifle, not try to make it accurate with lead bullets.
 

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Discussion Starter · #15 ·
The guns are Winchesters 1892 32-20 (32 WCF) and an 1894 32 Winchester Special (32-30).

Yes, it would be easier to just measure the chamber to the rifling. I want more details, so I’m going to use the Cerrosafe, unless we run into some unforeseen problems.

Yes, I intend to use cast bullets, especially if we get larger barrel dimensions than factory bullets.

It’s all a learning experience for me.

At this point I don’t think I would pour my own casts, but the way California is going, I don’t want to depend on whether or not some legislators are willing to let people buy guns and ammo.

Steve
 

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The guns are Winchesters 1892 32-20 (32 WCF) and an 1894 32 Winchester Special (32-30).

Yes, it would be easier to just measure the chamber to the rifling. I want more details, so I’m going to use the Cerrosafe, unless we run into some unforeseen problems.

Yes, I intend to use cast bullets, especially if we get larger barrel dimensions than factory bullets.

It’s all a learning experience for me.

At this point I don’t think I would pour my own casts, but the way California is going, I don’t want to depend on whether or not some legislators are willing to let people buy guns and ammo.

Steve
Let us know your info on both of your guns,
I bet someone on this forum can help.

I would cast for both of your rifles, you will
be shooting for around five to eights cents
a shot, and be able to tailor loads for different
tasks, like subsonic for small game and quiet,
to bigger game and longer ranges.

You can replace many 22lr jobs with cast in
many CF guns, even as big as a 30-06.

Many times you can get one mold that will work
good in many guns,

Remember this, fitting a boolit is not just knowing
the grove dia, many times the boolit needs to
be much bigger.
 

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Discussion Starter · #18 ·
Let us know your info on both of your guns,
I bet someone on this forum can help.
I would cast for both of your rifles, you will
be shooting for around five to eights cents
a shot, and be able to tailor loads for different
tasks, like subsonic for small game and quiet,
to bigger game and longer ranges.
You can replace many 22lr jobs with cast in
many CF guns, even as big as a 30-06.
Many times you can get one mold that will work
good in many guns,
Remember this, fitting a boolit is not just knowing
the grove dia, many times the boolit needs to
be much bigger.

To help get you started on loading for them,
I do believe you can better many of their loads,
if you know how to make a proper boolit and
know how to fit it to your gun.

If you can extrapolate, you can learn a lot
from this link on many calibers,

http://www.gmdr.com/lever/lowveldata.htm


http://www.gmdr.com/lever/3220w115_dat.htm

http://www.gmdr.com/lever/3220wtext.htm

http://www.gmdr.com/lever/32ws170_dat.htm

http://www.gmdr.com/lever/32wstext.htm
happie2shoot

I appreciate all the information. I'll make sure to post my results.

Thanks,
Steve
 

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Slugging or using Cerrosafe is big help when dealing with foreign military surplus rifles. I have run across 303 British rifles that have bores as large as .317 and 7.62 X 54 Russian as large as .312. Knowing the bore diameters make a large impact on improving accuracy.
 
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