• This community needs YOUR help today. We rely 100% on Supporting Memberships to fund our efforts. With the ever increasing fees of everything, we need help. We need more Supporting Members, today. Please invest back into this community. I will ship a few decals too in addition to all the account perks you get.



    Sign up here: https://www.muzzleloadingforum.com/account/upgrades
  • Friends, our 2nd Amendment rights are always under attack and the NRA has been a constant for decades in helping fight that fight.

    We have partnered with the NRA to offer you a discount on membership and Muzzleloading Forum gets a small percentage too of each membership, so you are supporting both the NRA and us.

    Use this link to sign up please; https://membership.nra.org/recruiters/join/XR045103

Has anyone tried casting lead for barrel bore measurement this way?

the hawken shop
Shop deals on ebay
Muzzleloading Forum

Help Support Muzzleloading Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Larry (Omaha)

Larry (Omaha)

62 Cal.
MLF Supporter
Joined
Aug 27, 2004
Messages
2,986
Reaction score
6,377
A poster on on another forum stated that he could not cast some lead for bore measurement because the breech plug needed to be removed. I have no need to cast lead for bore measurement, but wondered about a way to cast lead without removing the breech plug? Would this work?.............. Insert a wood dowel smaller than the bore, long enough to go from breech plug to about 1.25" short of the muzzle. Insert a trim to fit snug shotgun over powder card on top of the dowel. Cast your lead and then use a screw, ball puller to remove.
If anyone has tried this, or have comments I would be interested.
Flintlocklar
 
Larry (Omaha) said:
A poster on on another forum stated that he could not cast some lead for bore measurement because the breech plug needed to be removed. I have no need to cast lead for bore measurement, but wondered about a way to cast lead without removing the breech plug? Would this work?.............. Insert a wood dowel smaller than the bore, long enough to go from breech plug to about 1.25" short of the muzzle. Insert a trim to fit snug shotgun over powder card on top of the dowel. Cast your lead and then use a screw, ball puller to remove.
If anyone has tried this, or have comments I would be interested.
Flintlocklar
Click to expand...
Larry try a wet paper towel pushed down the bore. Pour ,let harden and then remove with a co dis-charger .

SM
 
Never did it, only molten sulphur, not have tested other stuff...

If I had to do this way I would put a large brass or bronze rod in the bottom of the bore, something to seal one or two inches below the height of the mouth and pour the lead. Then, by turning the rifle over, the brass or bronze bar, by its inertia, would cause the lead to come out downward by shaking the barrel and then no reason to unscrew the breech cap. I once made this way with a ball entered with a mallet to take an approximate measurement.

Just an idea but I don't see much point in proceeding in this way when sulphur and Cerrosafe can do the same without complication...

Erwan
 
Why go to the trouble of pouring molten lead into the barrel? It will shrink as it cools and won't be accurate and you'r are taking the risk of splashing lead on the gun. Tap an oversize slug or ball into the muzzle with a wood or other soft mallet. Remove with a screw or a brass rod in the barrel first to drive it out by shaking.
 
hawkeye2 said:
Why go to the trouble of pouring molten lead into the barrel? It will shrink as it cools and won't be accurate and you'r are taking the risk of splashing lead on the gun. Tap an oversize slug or ball into the muzzle with a wood or other soft mallet. Remove with a screw or a brass rod in the barrel first to drive it out by shaking.
Click to expand...
Amen to that!
 
The thermal expansion of lead is 16 X 10^-6 inches per degree F. Without going into the math, if the lead was at 600 degrees F when it started to solidify, it would shrink .0085 per inch when it cools to room temperature. Bullet and roundball molds are made larger than the finished casting size to allow for this.

If it were cast in a .50 caliber barrel, that means it would shrink .0085 X .50 = .0042 when it was measured. Obviously this doesn't represent the true bore size of the barrel because the cast slug would measure, .500 - .0042 = .4958 in diameter.

If someone does want to cast some lead in their barrel they must remember to apply some wax or oil to the bore before pouring any lead into it. If it happened to be totally oil free there is a very good chance that the lead would stick to the steel. Think about good old lead tin solder. The tin is in it to lower the melting point of the lead, not to make it stick to steel better so you see, if your luck is like my luck, you would end up with a soldered plug in your barrel if nothing was done to keep the lead from sticking.
 
Zonie said:
The thermal expansion of lead is 16 X 10^-6 inches per degree F. Without going into the math, if the lead was at 600 degrees F when it started to solidify, it would shrink .0085 per inch when it cools to room temperature. Bullet and roundball molds are made larger than the finished casting size to allow for this.

If it were cast in a .50 caliber barrel, that means it would shrink .0085 X .50 = .0042 when it was measured. Obviously this doesn't represent the true bore size of the barrel because the cast slug would measure, .500 - .0042 = .4958 in diameter.

If someone does want to cast some lead in their barrel they must remember to apply some wax or oil to the bore before pouring any lead into it. If it happened to be totally oil free there is a very good chance that the lead would stick to the steel. Think about good old lead tin solder. The tin is in it to lower the melting point of the lead, not to make it stick to steel better so you see, if your luck is like my luck, you would end up with a soldered plug in your barrel if nothing was done to keep the lead from sticking.
Click to expand...
Excellent advice as always!
 
If possible, I would call the manufacturer to ask them what they machine their barrel dimensions to first.

And yeah. something like cerosote is better to work with than other metals. It's used for chamber casts all the time to determine calibers of unknown arms. Even wax might work.
 
I think you meant Cerrosafe?
Cerrosafe, Cerrobend and similar castings alloys are made from bismuth and a few other metals. They has several unusual qualities, one being, that it actually expands slightly after it has hardened.
It also melts at a temperature that is lower than boiling water so any shrinkage it might have had due to cooling down is very small.

I used Cerrobend to cast the grip cap on the .40 caliber pistol I made.

CASE4.jpg
 
I’ve done it with ceresafe.
Put a card wad into the bore about 1” down. Turned a threaded rod 2” long (10-32) with a flat disk on one end - sat it on the card wad.
Poured ceresafe, pulled out with 10-32 rod.
Got wad out with wad jag.
 
I've poured laps before with all thread or an old cleaning brush down the middle. Have to use a lead catcher (steel wool is good for a dam).
Gave me the idea of using a flat head machine screw down the middle to use the conical underside of the head to expand the lead within the barrel by turn of the nut and then to pull it out.
I think a body could tinker their way into a measurement as reliable as slugging by driving it through.
 
Zonie said:
I think you meant Cerrosafe?
Click to expand...
I believe that is what he really meant. Good product available from Midway and Brownell's. It is reusable so is good investment. Putting a hunk of brass rod down the barrel first then a wad of paper to pour the cerrosafe onto works. When hardened turn rifle muzzle down and sorta 'pump' it all out with the brass rod jumping up and down.
 
Yup. That's what I meant. Thank you for the correction. I remember using the stuff in Pinewood Derby cars too to add weight. Bought it at a hobby shop.

Pinewood Derby cars are probably the most popular woodworking project in America. After about a dozen of them I was sure ready for the boys to be in Boy Scouts rather than Cubs!
 
If you barrel has an even number of lands and grooves, a dial caliper will give you what you want. There's a time line on measuring the casting before the slug expands. Otherwise, I believe there's some math that has to be done to determine the actual size.
 
Lead will shrink while cooling, giving you a false measurement.

Ball/Bullet mold cavities are slightly oversize to compensate for this.
 

Similar threads

S
Asking for a friend... Rusty bore issue?
2 3
Replies
41
Views
2K
N.Y. Yankee
N
boberator
Adjustable Barrel Lapping Tool
2
Replies
20
Views
1K
Rudyard
R
ThreeCedars
Looking for conical sizing advice
Replies
10
Views
593
stikshooter
S
dave_person
Making a Pattern 1756 Long Land British Musket
2 3 4
Replies
77
Views
4K
lexington1
lexington1
kh54
Minié ball casting results
Replies
5
Views
616
tjiann
tjiann

Latest posts

Back
Top