Bbl. Slugging

[sergeant69]

ok, so i wanna slug the bbl on my 44mag 629 due to the many posts here i have read. so................i get some egg sinkers and shove one down the bbl. and measure it. can anyone please tell me the exact proceedure? wood dowel? heavy hammer? one strike not 20? etc etc thanks!

[craig61a]

I have only slugged my rifles, but what I do is run an oiled patch through the bore, apply some lithium grease to the end of the sinker that will be inserted into the bore, apply some lithium grease to the muzzle of the bore and place the sinker on the muzzle. A piece of scrap wood on top the sinker and a few wacks with a hammer to get the sinker started. That will keep the outer part of the sinker from being shaved off as it is driven into the bore. Once the sinker is in the bore and about flush with the muzzle I use a hardwood dowel to push it the rest of the way through. Of course for the rifle I use sections of dowel 6" long. You can probably use one section for the pistol.

You will want to secure the pistol somehow with the muzzle pointing up. A vice with some pine blocks around the barrel to prevent damaging it with a surface below to keep the pistol from sliding down should work.

[mdi]

This is how I did my 629. I removed the cylinder and secured the bbl/frame in a padded vise. Lightly oiled the bbl and slug. Positioned the slug/sinker in the muzzle and carefully pounded the slug into the muzzle with a plastic mallet, stopping way short of full insertion; leave a about a quarter of the slug outside the bbl. There will be a "ring" of lead sheared off the slug. Being very careful not to directly hit the muzzle even though I use a plastic mallet. Using a brass drift I drove the slug, very carefully, into the muzzle and using a heavy hammer finished driving the slug through, with a 1/4' brass rod. I did it twice just to make sure I had a good measurement. I use 1" vernier micrometers (I don't like digital) to measure the slug. Works for me...


Edit 7/1. McMaster Carr has brass rod http://www.mcmaster.com/#brass-alloy-rods/=7rszrf 1/4" x 6' for around $10.00

[fourarmed]

I use a steel bar about 6" long. Remove cylinder, insert bar in frame opening and lay it across the jaws of your bench vise. Then using some sort of padding (I took a thick paperback book and slit the spine at the middle) close the vise on the gun. The bar supports it vertically much better than the vise alone.

[Pepe Ray]

Commenting re; Crag61a's remark about using hardwood dowels.

If you've been lucky enough to have never had a dowel split and wedge w/i the bbl, you'll be in for a treat. If you do much "slugging" it's bound to happen.

brass rods of the correct length and diameter are the preferred tool. Of course, many times the preferred tools can be hard to find and are expensive when located.
My solution to this problem (being cheap), is to salvage as wide a variety of pistol cartridge cases as possible. From .25ACP up to 40S&W have been adequate for me. By using these on the ends of the wooden dowel sections you protect the ends from the damage invariably incurred while pounding.
For a long bbl you may need as many as 10 similar cases.
Wooden dowels are STILL inferior to brass rod but with due caution in selecting the dowels, you can save a few bucks.
Pepe Ray

[sergeant69]

lots of good ideas. thanks

[mooman76]

Slugging the cylinders is more important than slugging the barrel but I like to slug the barrel too. If your cylinders are smaller than the barrel, it doesn't matter what the barrels slugs at because you will have poor accuracy.

[DCP]

You will never use wood again after you split on and cant get it out

BRASS ONLY or Soft Steel wrap every 2 in or less with electrical tape just under the bore size

I also use a brass hammer



Menards has them


Commenting re; Crag61a's remark about using hardwood dowels.

If you've been lucky enough to have never had a dowel split and wedge w/i the bbl, you'll be in for a treat. If you do much "slugging" it's bound to happen.

brass rods of the correct length and diameter are the preferred tool. Of course, many times the preferred tools can be hard to find and are expensive when located.
My solution to this problem (being cheap), is to salvage as wide a variety of pistol cartridge cases as possible. From .25ACP up to 40S&W have been adequate for me. By using these on the ends of the wooden dowel sections you protect the ends from the damage invariably incurred while pounding.
For a long bbl you may need as many as 10 similar cases.
Wooden dowels are STILL inferior to brass rod but with due caution in selecting the dowels, you can save a few bucks.
Pepe Ray

[Fugowii]

http://www.mcmaster.com/#brass-rods/=7rjdcx

is your friend. I just picked up a couple of brass rods from them to slug my Win '94. Good selection and they ship quick.

[405]

Slug both the bore and the cylinder throats. That way you'll have an idea what you're dealing with. The relationship between the two along with cylinder to bore alignment are the keys to best potential accuracy in a revolver. My most accurate revolvers have the cylinder throats equal to & up to about .001" greater than the bore's groove diameter. Then the bullets are minimally crimped and sized equal to cylinder throat diameter.

[geargnasher]

Listen to the guys telling to slug the cylinder throats, too.

Now, for the kicker no one mentions: How to measure the S&W pentagonal rifling with common tools?

Gear

[Bass Ackward]

I take a wooden dowel and drill the ends of it slightly with a way smaller drill. Dip both ends in epoxy with the excess glass when I am glassing a stock. Wood absorbs the epoxy and walla, an indestructible slugging rod.

[azcruiser]

Anyone ever use Cerrosafe to slug a barrel .Know it works in rifle chambers

[blackthorn]

Cerrosafe will work-----BUT----once poured it will measure under sized for the first hour---then right on at the one hour point---and then it increases in size for a while before stabilizing somewhat oversize. There is a formula for determining the right size after stabilization occurs, and I suggest you may want to contact the manufacturer as they make several different cerrosafe alloys. The other problem you might encounter is that if you pour in too much you run the risk of "locking" the cast into the barrel and having to melt it out.

[alamogunr]

Listen to the guys telling to slug the cylinder throats, too.

Now, for the kicker no one mentions: How to measure the S&W pentagonal rifling with common tools?

Gear

Somewhere back in the dark corners of my memory, I seem to remember there was someone who contemplated machining a device(V shaped tool) that would enable one to measure a slug from barrels with odd numbers of grooves. Anyone else remember something like that?

John
W.TN

[JonB_in_Glencoe]

Listen to the guys telling to slug the cylinder throats, too. Now, for the kicker no one mentions: How to measure the S&W pentagonal rifling with common tools? Gear

very simple !!!
use a strip of aluminum pop metal, wrap it around the slug
measure, then subtract twice the thickness of the pop can metal.
Jon

[sergeant69]

i'm gonna sit on the sidelines for this one!

[alamogunr]

very simple !!!
use a strip of aluminum pop metal, wrap it around the slug
measure, then subtract twice the thickness of the pop can metal.
Jon

Somehow that doesn't sound accurate to me. I guess I could use a very thin feeler gage. Would prefer to have a tool that would let me measure directly. Maybe someday I will remember where I saw the V tool concept.

John
W.TN

[blackthorn]

This may be what you are looking for? It may not be exactly as it appeared in the thread you seek because I tend to "edit" a bit to save space.

To measure a bullet with an odd number of groves, make a small metal “V” out of a metal strip approximately 3/8 inch wide and inch or so long, bent to a 90 deg “V”. Use metal that is of thick enough material to allow you to file the outside pointy elbow of the “V” flat, concentric to the two legs. After you finish take a 30 caliber bullet, measure it with a micrometer and record the measurement. Then put that 30 cal bullet inside the “V” and mic the two together with the flat against one anvil of the mic and the other movable anvil held against the bullet. Write that figure down and subtract the two. Next mic the five groove bullet you want to know the groove diameter of in the “V” tool and then merely subtract the difference you got initially between the “V” and 30 cal bullet and just the 30 cal bullet. For example, if your 30 caliber bullet mics .308, and in the “V” tool it mics .333, the difference is .025. Now you mic your five groove bullet in the “V” tool and if it measured .339, subtract the .025 difference and your five groove bullet diameter is .314. This method is a lot more accurate then calipers and lot less expensive than buying a “V” mic.

To measure the diameter of a bullet with an odd number of groves, if you don't have a 60 degree block you can use a 90 or 108 degree block.


Alternately, you can calibrate it with an accurate diameter pin, like a drill rod and then measure the bullet and V-block with an ordinary micrometer or calipers. Then use the math below.

a = the included angle of the V-block,
t = the thickness of the V-block from the bottom of the V to the bottom,
h = the measured height of the bullet and V-block,
d = the diameter of the bullet.

For “a” as an example using a 5 groove bullet, the included angle (a) is 108°, assume the V-block "thickness" (t) is .250" and the measured total height (h) is .5854", then:
d = 2(.5854 - .250)/ (1 + 1/sin (108/2))
d = 2(.5854 - .250)/ (1 + 1/sin 54)
d = 2(.5854 - .250)/ (1 + 1/.80901)
d = 2(.5854 - .250)/ (1 + 1.23607)
d = 2(.5854 - .250)/ (2.23607)
d = 2(.3354)/(2.23607)
d = .6708/2.23607
d = .300

A way to determine the V-block thickness (t) is to measure a known cylinder and then calculate it from:

t = h - (d/2) (1+1/sin(a/2) )

Hope this helps!

[DCP]

Plastic shim work good too.

So how can these 2 ways not be accurate?

I have seen 2 or 3 people get different readings on the same micrometer.

That's why some have a ratchet on the barrel



very simple !!!
use a strip of aluminum pop metal, wrap it around the slug
measure, then subtract twice the thickness of the pop can metal.
Jon

[DCP]

Plastic shim works good too.

So how can these 2 ways not be accurate?

I have seen 2 or 3 people get different readings on the same micrometer.

That's why some have a ratchet on the barrel



very simple !!!
use a strip of aluminum pop metal, wrap it around the slug
measure, then subtract twice the thickness of the pop can metal.
Jon

[sergeant69]

This may be what you are looking for? It may not be exactly as it appeared in the thread you seek because I tend to "edit" a bit to save space.

To measure a bullet with an odd number of groves, make a small metal “V” out of a metal strip approximately 3/8 inch wide and inch or so long, bent to a 90 deg “V”. Use metal that is of thick enough material to allow you to file the outside pointy elbow of the “V” flat, concentric to the two legs. After you finish take a 30 caliber bullet, measure it with a micrometer and record the measurement. Then put that 30 cal bullet inside the “V” and mic the two together with the flat against one anvil of the mic and the other movable anvil held against the bullet. Write that figure down and subtract the two. Next mic the five groove bullet you want to know the groove diameter of in the “V” tool and then merely subtract the difference you got initially between the “V” and 30 cal bullet and just the 30 cal bullet. For example, if your 30 caliber bullet mics .308, and in the “V” tool it mics .333, the difference is .025. Now you mic your five groove bullet in the “V” tool and if it measured .339, subtract the .025 difference and your five groove bullet diameter is .314. This method is a lot more accurate then calipers and lot less expensive than buying a “V” mic.

To measure the diameter of a bullet with an odd number of groves, if you don't have a 60 degree block you can use a 90 or 108 degree block.


Alternately, you can calibrate it with an accurate diameter pin, like a drill rod and then measure the bullet and V-block with an ordinary micrometer or calipers. Then use the math below.

a = the included angle of the V-block,
t = the thickness of the V-block from the bottom of the V to the bottom,
h = the measured height of the bullet and V-block,
d = the diameter of the bullet.

For “a” as an example using a 5 groove bullet, the included angle (a) is 108°, assume the V-block "thickness" (t) is .250" and the measured total height (h) is .5854", then:
d = 2(.5854 - .250)/ (1 + 1/sin (108/2))
d = 2(.5854 - .250)/ (1 + 1/sin 54)
d = 2(.5854 - .250)/ (1 + 1/.80901)
d = 2(.5854 - .250)/ (1 + 1.23607)
d = 2(.5854 - .250)/ (2.23607)
d = 2(.3354)/(2.23607)
d = .6708/2.23607
d = .300

A way to determine the V-block thickness (t) is to measure a known cylinder and then calculate it from:

t = h - (d/2) (1+1/sin(a/2) )

Hope this helps!


everybody that understands this raise your hand.:shock:

[alamogunr]

I guess I will have to raise my hand. That was the kind of explanation I was looking for. Since I am only interested in measuring slugs from my S&W revolvers with their 5 groove barrels, I don't need to know how the included angle is derived(it would be interesting though) for other odd numbers of grooves

John
W.TN

[sergeant69]

I guess I will have to raise my hand. That was the kind of explanation I was looking for. Since I am only interested in measuring slugs from my S&W revolvers with their 5 groove barrels, I don't need to know how the included angle is derived(it would be interesting though) for other odd numbers of grooves

John
W.TN

well, i can add 2 plus 2, on a good day. so there!:drinks:

[alamogunr]

This may be what you are looking for? It may not be exactly as it appeared in the thread you seek because I tend to "edit" a bit to save space.

To measure a bullet with an odd number of grooves, make a small metal “V” out of a metal strip approximately 3/8 inch wide and inch or so long, bent to a 90 deg “V”. Use metal that is of thick enough material to allow you to file the outside pointy elbow of the “V” flat, concentric to the two legs. After you finish take a 30 caliber bullet, measure it with a micrometer and record the measurement. Then put that 30 cal bullet inside the “V” and mic the two together with the flat against one anvil of the mic and the other movable anvil held against the bullet. Write that figure down and subtract the two. Next mic the five groove bullet you want to know the groove diameter of in the “V” tool and then merely subtract the difference you got initially between the “V” and 30 cal bullet and just the 30 cal bullet. For example, if your 30 caliber bullet mics .308, and in the “V” tool it mics .333, the difference is .025. Now you mic your five groove bullet in the “V” tool and if it measured .339, subtract the .025 difference and your five groove bullet diameter is .314. This method is a lot more accurate then calipers and lot less expensive than buying a “V” mic.

To measure the diameter of a bullet with an odd number of groves, if you don't have a 60 degree block you can use a 90 or 108 degree block.


Alternately, you can calibrate it with an accurate diameter pin, like a drill rod and then measure the bullet and V-block with an ordinary micrometer or calipers. Then use the math below.

a = the included angle of the V-block,
t = the thickness of the V-block from the bottom of the V to the bottom,
h = the measured height of the bullet and V-block,
d = the diameter of the bullet.

For “a” as an example using a 5 groove bullet, the included angle (a) is 108°, assume the V-block "thickness" (t) is .250" and the measured total height (h) is .5854", then:
d = 2(.5854 - .250)/ (1 + 1/sin (108/2))
d = 2(.5854 - .250)/ (1 + 1/sin 54)
d = 2(.5854 - .250)/ (1 + 1/.80901)
d = 2(.5854 - .250)/ (1 + 1.23607)
d = 2(.5854 - .250)/ (2.23607)
d = 2(.3354)/(2.23607)
d = .6708/2.23607
d = .300

A way to determine the V-block thickness (t) is to measure a known cylinder and then calculate it from:

t = h - (d/2) (1+1/sin(a/2) )

Hope this helps!

Thanks, Blackthorn. Since S&W barrels are the prevalent use for a V-block, I may try to find a machine shop to make one with the 108º included angle. Also those pin gages that find little use, except in the sizes that are close to common revolver calibers, can be used to find the value of "t".
John
W.TN

[iammarkjones]

This may be what you are looking for? It may not be exactly as it appeared in the thread you seek because I tend to "edit" a bit to save space.

To measure a bullet with an odd number of groves, make a small metal “V” out of a metal strip approximately 3/8 inch wide and inch or so long, bent to a 90 deg “V”. Use metal that is of thick enough material to allow you to file the outside pointy elbow of the “V” flat, concentric to the two legs. After you finish take a 30 caliber bullet, measure it with a micrometer and record the measurement. Then put that 30 cal bullet inside the “V” and mic the two together with the flat against one anvil of the mic and the other movable anvil held against the bullet. Write that figure down and subtract the two. Next mic the five groove bullet you want to know the groove diameter of in the “V” tool and then merely subtract the difference you got initially between the “V” and 30 cal bullet and just the 30 cal bullet. For example, if your 30 caliber bullet mics .308, and in the “V” tool it mics .333, the difference is .025. Now you mic your five groove bullet in the “V” tool and if it measured .339, subtract the .025 difference and your five groove bullet diameter is .314. This method is a lot more accurate then calipers and lot less expensive than buying a “V” mic.

To measure the diameter of a bullet with an odd number of groves, if you don't have a 60 degree block you can use a 90 or 108 degree block.


Alternately, you can calibrate it with an accurate diameter pin, like a drill rod and then measure the bullet and V-block with an ordinary micrometer or calipers. Then use the math below.

a = the included angle of the V-block,
t = the thickness of the V-block from the bottom of the V to the bottom,
h = the measured height of the bullet and V-block,
d = the diameter of the bullet.

For “a” as an example using a 5 groove bullet, the included angle (a) is 108°, assume the V-block "thickness" (t) is .250" and the measured total height (h) is .5854", then:
d = 2(.5854 - .250)/ (1 + 1/sin (108/2))
d = 2(.5854 - .250)/ (1 + 1/sin 54)
d = 2(.5854 - .250)/ (1 + 1/.80901)
d = 2(.5854 - .250)/ (1 + 1.23607)
d = 2(.5854 - .250)/ (2.23607)
d = 2(.3354)/(2.23607)
d = .6708/2.23607
d = .300

A way to determine the V-block thickness (t) is to measure a known cylinder and then calculate it from:

t = h - (d/2) (1+1/sin(a/2) )

Hope this helps!

I understand the principal but since your equation would allow for an accurate reading out to 00.0001 on most mics, a homemade angle block is the only part of this I wonder about. WAIT! The calibration with a known diameter pin! lol blackthorn this is scary smart! Sadly I realize that I can use this at work....

[Crash_Corrigan]

I bought a nice big muffin of Cerrosafe from Rotometals when I made my last order for BCPR alloy. Since then I have been busy making chamber casts of all my shooting irons.

You would be amazed at the different sizes you come up with in a 9 MM! No wonder my Browning Hi Power did not like those .356 sized lead boolits. It loves having .358 or .3575 sized fodder....not that small stuff that works ok in my EAA Witness.

Cerrosafe is so easy and fast to use that once you try it out you will never even consider using the lead slugging festivities involving rods and dowels and such.

I make sure that the chamber is clean along with the barrel. Then I run an oily patch through the bore and also the chamber. Then I put on the end of a cleaning jag an oily patch and push it through from the muzzle end to about two inches short of the chamber.

I melt the cerrosafe in an old tuna fish can (clean is nice) and using a heavy piece of construction paper rolled into a funnel I pour the heated alloy into the chamber. I use a propane torch to heat the alloy in the TF can. I bent a spout into the can prior to heating the alloy and it makes it easier. Take care not to put too much alloy into the chamber as if it gets into the area behind the projected case bottom it can cause a problem.

However even if you have that problem...heating with a torch will again reduce the alloy to liquid but you might lose some of this stuff...so be careful pouring it.

Once the alloy has hardened it will shrink a mite and allow you to punch out the plug using the cleaning rod with the jag on it.

Lay it aside and wait 60 minutes and then take and write down your measurements. It will initially shrink (allows you to remove it easily) and then in 60 minutes time it will accurately puff up to the original dimension of your chamber and barrel. However this window of time only runs for a bit. If you wait too long to measure then you had best do it again.

[blackthorn]

O.K. Here is what information I have collected on the use of Cerrosafe (from my notes):



CERROSAFE:

While the makers of Cerrosafe produce several different alloy combinations, the one we are concerned with consists of the following percentages: Bismuth - 42.50, Lead – 37.70, Tin – 11.30, Cadmium – 8.50. Note: Cadmium is very toxic so use good hygiene and avoid breathing the fumes. We all know the harmful effects of inhaling or digesting lead. Cadmium, is even worse. Its compounds are extremely toxic even in low concentrations, and will bioaccumulate in organisms and ecosystems. So use similar but even greater caution when working with Cerrosafe as you would when handling lead.

Notes:
 Melts between 158 and 190 degrees Fahrenheit
 Should be melted in a clean iron ladle without direct flame on the product.
 The chamber being cast should be cleaned thoroughly and a thin coat of oil or graphite applied.
 Reusable

Contraction - expansion factor versus time, after casting, measured in inches per square inch:
 2 minutes -.0004"
 6 minutes -.0007"
 30 minutes -.0009"
 1 hour +-.0000"
 2 hours +.0016"
 5 hours +.0018"
 7 hours +.0019"
 10 hours +.0019"
 24 hours +.0022"
 96 hours +.0025"
 200 hours +.0025"
 500 hours +.0025"

Basic Instructions:
 Plug the bore about one inch ahead of the throat of the firearm using an appropriate size cleaning patch.
 Pour the molten alloy directly into the chamber until full and allow it to cool, it will turn a shiny silver color. As soon as it has cooled enough that it is no longer a liquid (and doesn't present a burn hazard), run a rod into the bore from the muzzle and tap the casting out of the chamber. Take care not to overfill the chamber as the alloy will then run into the locking lug area, making removal extremely difficult. Any recessed areas can be plugged with modeling clay prior to pouring.
 During the first 30 minutes of cooling Cerrosafe shrinks and then begins to expand. At the end of one hour it should be "exactly" chamber size. The Cerrosafe will manage to find its way into some pretty tight places so it is easier to have the rifle stripped to the frame prior to commencing the job. Clean the chamber, lightly oil it (then wipe it out with a patch), plug the barrel at a point that allows the formation of about an inch of rifling to be included in the cast, and cast it.

As Crash notes, if left too long the cast "grows" and will need to be redone (or use the formula above). An alternate casting material is a mix of 10 to 30% graphite and the balance Sulphur. Once cast the casting will not move in either direction. Hope you find this helpful.