Advice on slugging bore

[MTyotehunter]

Never done it, tips tricks? Handgun and rifle.
Thank you

[oldhenry]

I've only done one rifle years ago: a #3 Ruger in 45-70 which is about the same as a handgun.

I've done several handguns & this is how I did it:

#1: The easiest is the pistol/automatic (as in 1911).
A. Disassemble & get down to the bare barrel.
B. Acquire a solid lead fishing weight slightly larger than the bore diameter (pointed bullet type works best for me)
C. Coat the bore with a liberal dose of grease (I use common axle grease)
D. Coat the led weight with same grease
E. I introduce the pointed end of the lead weight into the muzzle of the barrel & tap it into the muzzle with a plastic tipped hammer. When the entire weight is in the barrel hopefully a lead ring will be left @ the muzzle (this lets you know the weight fits OK).
F. With a wooden dowel of a slightly smaller dia. than the bore tap the weight down the bore (It isn't unusual for heavy taps to be requires to get it started).
G. Capture the lead weight @ the chamber end with a rag or paper towel.

#2: The revolver starts out exactly the same.
A.I usually like to stop the weight before the point where the barrel threads begin.
B. With several short lengths of the dowel from the forcing cone drive the weight back out toward the muzzle. I usually do this with a piece of wood small enough to enter the area occupied by the cylinder & I use the same plastic tipped hammer on that piece of wood to force the sections of dowel back out the muzzle.
C. Add more sections of dowel until the weight exits the muzzle.
D. With another lead weight drive it down the barrel from the muzzle until it exits @ the forcing cone.

If the 2 revolver weights measure the same, you can deduct that there is no thread choke. If the weight that was driven completely through measures less, you can deduct that you have some thread choke.

Others may have some additional tips that they use or more info.

I hope this helps.

Good luck!
Henry

[BigAlofPa.]

I second the fishing weight idea. It works very well.

[Outpost75]

Read the sticky!

[kungfustyle]

Stay away from wooden dowels, Use brass or steel wrapped in electrical tape. USE SOFT LEAD!!! USE GREASE of some type Crisco works in a pinch. Follow that and you shouldn't have a problem.

[Sig556r]

Never had problem with appropriately-sized wooden dowel to slug barrels

[gwpercle]

For fishing weights , the pear shaped bell sinkers work well . I bought an assortment of sizes , found one whose diameter was a bit larger than the bore and drove it in with a mallet and short brass rod .
Start the pointy end into the muzzle and be careful ...lube up bore well and I used a longer aluminum rod to tap it through...wood can break !
Keep everything straight and you can always use the other sinkers to fish with .

[Conditor22]

I found that the barrel sinkers worked well for me, since then I just cast pure lead boolits of the desired caliber and use them, if the boolit is a little small I'll smack it on an anvil a couple times making it shorter and fater.

Wood works, but be very careful! only use dowels with perfectly straight grain. you get a dowl the shears due to cross grain it will get seriously wedged and you'll need a gunsmith to remove it.

I use a steel rod wraped with tape till it barely slides into the barrel, brass is safer, aluminum bends.

Many people act like they have never seen the

Forum: Classics & Stickies http://castboolits.gunloads.com/foru...s-amp-Stickies

there is a literal ton of information there.

AND the STICKIES at the top of each category

[edctexas]

Be sure the sinker is pure lead and not zinc! I have seen zinc fishing weights. Try biting into it with side cutters.

Ed C

[TNsailorman]

I was in WallyWorld the other day and looked for some lead sinkers in vain. The ones hanging on the rack all said in small letters that they were a "non lead product". They looked like the old time lead sinkers but were not. I will have to go to one of the local fish and bait shops and see if I can find some. james

[44magLeo]

On rifles I slug the barrel three times. Two as described but one just inside the muzzle, one all the way through and one pound cast. I fill up an old case with lead. Insert in chamber Drive a lead slug in from muzzle till contacts lead in case then pound on it to get a slug to match the throat area of barrel.
The one in muzzle gives me the bore size. The one all the way through gives me any tight spots. The pound cast gives me the size of the chamber just ahead of the case as well as up into the rifling. This tells me how long the throat and it's diameter.
I can use these last specs to determine if just a thou or two is enough oversize for best fit. A snug fit in the throat my be bigger than the bore size.
To make long pure lead slugs for the pound cast I drill holes of the right diameter in wood blocks, pour the lead and split the wood off.
Boolit molds work for the others.
Leo

[44magLeo]

One more thing, on revolvers slug each chamber mouth as well as the barrel. They may not all be the same. Sizing to the largest chamber mouth often gives better accuracy. Just check to see that sized this large and loaded in cases fits in all chambers.
Leo

[MTyotehunter]

Lots of good advice! Trying to soak in as much as I can

Sorry outpost75, I guess I missed the sticky, I’ll look again

[georgerkahn]

While I concur with what other posters have written, I have cast pure-lead bullets, after which I squeeze them a bit in a bench vise. This works best as soon as possible after casting. Then I use (MolyGraph) grease, tap the now-fattened bullet through, and measure. In NYS lead sinkers are not available in the retail market.
An alternative, which I both have and works very well, are kits purveyed by Lead Bullet Technology. Their URL is http://www.lbtmolds.com/measurebore.shtml
A teeny-tad costly, imho, but -- again -- they are very hight quality and, for my needs, performed well.
Good luck!
geo

[Taterhead]

Has anyone else encountered lead sinkers that were harder than expected? I've found a few recently that were not useful for slugging the barrel. I figured that the mfg was using who-knows-what recycled alloy.

[georgerkahn]

Taterhead -- Lead, from what I see, is now in fewer and fewer products. Where it is a requisite component, a California warning oft appears on it indicating its hazards. Rather than have two separate product lines -- lead or lead-free -- I suggest many manufacturer only market lead-free sinkers.
Interestingly to me, I just received a fairly large fishing tackle catalog, and while in previous editions they had a little asterisk next to their lead sinkers/split shot indicating they may not be sold in my state -- in this years' catalog no such distinction is made. Hence, I'd guess they're all now "lead free".
Just a couple cents' thought on subject...
geo
This is why I provided the URL on the LBT kits.

[R. Dupraz]

Now you can do what you want but under no circumstances use a wooded dowel to hammer a lead slug through a rifle bore. Why you ask? because it's likely that at some point the dowel will break and splinter in the bore jamming it and the slug in the bore. Then there is a major major problem that some one else will have to fix. A pistol bore maybe.

I use a steel rod under bore size enough that I can wrap at intervals with electrical tape as has been already been mentioned.

Commercial.Muzzle loader balls that are just over size can be used in a pinch to slug bores. They are always soft lead.

[Carrier]

Can’t get any lead sinkers where I’m at. Used a Hornady .50 caliber round ball to slug my 1873 Trapdoor. Put some Hornady Unique case lube on ball, oiled the barrel, whacked it into the muzzle with a plastic dead blow hammer, then used a 3/8” brass rod and came out perfect out of the breach.

[robg]

did it by mistake had a squib load with a lead load just pushed boolit out and measured it .

[Outpost75]

Lots of good advice! Trying to soak in as much as I can

Sorry outpost75, I guess I missed the sticky, I’ll look again

"Slugging the barrel" ala the old Lyman handbooks applies only for straight-cased, black powder style rifles chambered for "Cowboy" cartridges using revolver ammo, or rifle cartridges like the .45-70 in which the rifling simple starts in front of the case mouth with little or no transition.

For everything else, to determine the correct bullet diameter for a rifle, the groove diameter of the barrel is NOT the determinant.
INSTEAD you want to measure the "throat," or "ball seat", which is the unrifled portion of your rifle barrel ahead of the case mouth, before the rifling starts.

The best way for accurate measurement and easiest to do is to upset a throat slug, to make a "pound cast." For most .30 cal. rifles an easy way to do this is to take a dead soft, pure lead slug, such as a factory .38 Special 158-grain LRN projectile you have pulled, and drop it into the chamber. Then use a 3/8" diameter brass rod to drive the slug into the neck of the chamber until the 3/8" diameter of your brass rod comes to a hard stop against the chamber shoulder. Then just knock the slug out from the muzzle, and you will effectively capture the chamber NECK diameter (which determines safe release clearance, limiting maximum bullet diameter), the transition from the case neck to the "throat", (the UNRIFLED portion ahead of the chamber mouth before the rifling starts) and the conical "forcing cone" section at the origin of rifling.

Attachment 234859Attachment 234860

In REVOLVERS you want to measure the diameter of the cylindrical "throat" or "ball end" of each chamber in the cylinder ahead of the case mouth. This is best done by using a set of round steel gage pins. Lacking these, remove the cylinder and tap dead-soft pure lead round balls or slugs through each chamber and measure them with a micrometer.

A method widely used for rifles is to start with a sized case with DEAD primer in its pocket. Heat your lead pot, then fill the sized case with DEAD primer plugging the flash hole, and generously overflow the case. After the lead cools, clean all spilled lead off the case exterior, then file the exposed lead FLUSH to the case mouth.

Now take a piece of PURE lead buckshot or a short chunk of pure lead wire and drop it into the EMPTY chamber, letting it fall into the throat of its own weight. (With very long throats use a longer piece of wire or a SOFT bullet with long bore-riding nose and not a long grooved section).

Insert your lead-filled dummy case and GENTLY tap it into the chamber using a piece of brass rod until you can close the breech. You are using the lead-filled dummy case to force the lead slug into the ORIGIN of rifling. In short throated barrels it helps to drive the slug first into the origin of rifling, far enough to chamber the lead dummy behind it, then close the bolt and upset the slug against the lead dummy using a Brownell Squibb Rod threaded onto the end of your cleaning rod. You don't need to use a hammer, just raise up and let the weight of the rod when dropped make many light taps of the squibb rod against the slug until you get a clear "ringing" sound. It need go no farther!

What you want to measure is the diameter of the UNRIFLED portion of the chamber forward of the case neck BEFORE the rifling starts! Extract the dummy and GENTLY tap the lead slug out and measure it. THAT is the diameter you want to size your bullets to! Using Cerrosafe, etc. is more trouble and you then need to compensate for shrinkage, etc.

The upset pure, dead-lead slug is exact and straight forward! If you forget EVERYTHING you ever read about slugging barrels and simply cast chambers from now on, and get bullets to FIT THE THROAT you will be far happier in the long run.

The limiting factor in maximum safe bullet diameter is neck release clearance. You MUST measure the neck diameter of the chamber on the cast. A correct pound cast will get you a portion of the case mouth and its transition angle to the throat or ball seat, so that you can measure neck diameter at the mouth and throat diameter of the ball seat. The loaded cartridge neck diameter must not be larger than 0.0015" SMALLER than the chamber cast at that point, to ensure safe expansion for bullet release.

In most rifles the largest bullet diameter which chambers and enables extraction of a loaded cartridge without debulleting or the bullet telescoping deeper into the case is best. Light marking of the forepart of a rifle bullet which does not cause debulleting upon extracting a loaded round, without "telescoping" the bullet deeper into the case is OK.

Attachment 234861

In a typical .30-'06 a bullet diameter of .310" is correct for a new SAAMI chamber, as this represents the ball seat diameter of a "minimum"chamber. If your barrel has been fired more than 1500 rounds with full-power jacketed loads .311" will be a better fit. In a milsurp rifle which has been fired a good deal, a .312" will fit just fine and still have adequate neck release clearance when using GI brass in a typical military 03A3 Springfield or US M1917 chamber. It may provide useful information to assemble a DUMMY round with larger .313" or .314" bullet and mark the case neck with Dychem or black felt tip marker and attempt to chamber and extract it. Marking or rubbing on the die marker will shot you where the fit is too tight. If your cases are a bit long, or your crimp excessive you will get a bulge of the case mouth or shoulder. If so, this test will reveal it, so that you can make the necessary adjustments, trimming cases and/or backing off the seating die to reduce the amount of crimp.

Measuring a pound cast is really necessary to get best performance most milsurps. This is because large groove diameters and huge throats are common , especially in wartime .303 British rifles and in Russian M91/30s and Chinese copies whose chambers are notoriously sloppy! In these rifles a bullet with full-diameter, tapered forepart, rather than the typical Lyman "double-cylinder" groove diameter body and bore diameter forepart is best. Accurate 31-215B is a good example of the full-diameter, tapered forepart bullet designed to fit WW2-era .303s and 7.62x54Rs:

Let's review an example of chamber neck diameter and bullet fit:

A typical Finnish M39 7.62x54 chamber neck is 0.340". Typical case mouth wall thickness of Norma commercial brass is 0.013," so .340" minus twice neck thickness (0.026") = .314", minus 0.0015 for safe radial expansion of the neck for release clearance = .3125" max. bullet for a typical Finn chamber in an M24, M27, M28, M28/30 or M39.

WW2-era Russian and Chicom Mosin-Nagant rifles very often have throats as large as .316" and with groove diameters of .314", like a wartime British .303! If you expect anything resembling normal accuracy you MUST cast your chamber, measure it, and then buy a mold which fits your THROAT, not the groove diameter of the barrel. Use .30 cal. gaschecks, pressing them on by hand and then pushing the base of the bullet against a table edge until the gascheck is bottomed against the bullet shank. Only then size the bullet. Otherwise the GC will not be seated squarely on the base of the bullet and any hope for accuracy goes out the window.

And there you have it, and with correct bullets which "fit" your milsurp rifle can shoot like this:

Attachment 234858

P.S. - You can apply exactly same principles above to an auto pistol barrel. Easy to do with removable barrel.
My experience has been that most Euro barrels chambered to CIP or NATO STANAG 4090 need .357-.358 bullets.
Most commercial US barrels with SAAMI chambers require .356-.357 bullets, but many have throats so short and tight they won't shoot lead accurately unless reamed. A few may have very tight, minimum chambers so that rounds loaded with a bullet larger than .355" won't do in the gun! DougGuy can correct the above for you if you send him the barrel only.

Seating bullets deeper in small capacity pistol cases such as 9mm, so that rounds past a "plunk" test may cause a DANGEROUS pressure spike. DO NOT seat bullets in 9mm any shorter than the published source of pressure tested data recommends!