Dumb question on slugging a barrel

[8mmFan]

Hi All,

So...all of the barrel-slugging posts and vids have the slug going from the muzzle end, out the back of the chamber.

My question is why wouldn’t you go in the opposite direction, from the chamber end toward the muzzle? Isn’t the rifling diameter more important in the last six inches or so of the barrel than the front end? I’m sure I’m missing something here, like gasses pushing past the bullet as it starts down the barrel, etc. But for accuracy it seems like the most important bullet-barrel fit would be at the end of the rifle where the bullet has it’s last contact.

I have a Brazilian mauser that I have to do this for, which is why I’m asking.

Thanks for putting up with a probably foolish question. I’m just curious as to the answer.

8mmFan

[DAFzipper]

The slug will be the smallest diameter of the barrel regardless of which way you drive it through.

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[Der Gebirgsjager]

I too have noticed that a seeming preponderance of board members seem to favor slugging from the muzzle. I agree with you, and always advise to slug from the chamber end. For one thing, it's easy for whatever you're using to push the slug into the barrel to slip off and damage the crown. Inserting the slug from the chamber, through the throat, and into the bore is rather like a funnel.

[Hossfly]

I always push slug from chamber to muzzle but you might have a barrel that you cant or don’t want to take apart
To do that way so either way would be acceptable.

[Texas by God]

It always depends on the gun. I slug from breech to muzzle if possible; but it is not possible on many designs of gun( lever actions, revolvers, etc.)

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[Dusty Bannister]

If you slug from the breech, there is a chance you can bugger the chamber and that is hard to fix. From the muzzle, if you bugger the crown, you can rework it. Then if you have a worn throat, you probably should just do a chamber cast, either cast or hammer formed. No one is stuck with just one method.

[8mmFan]

Ah! Thanks for all of the quick replies, guys. Based on what all of you have said, I think I will slug it from the chamber.

In order not to “bugger” the chamber ( ;-) ), I’ll use a wooden dowel. Can’t imagine hurting the metal with a piece of wood.

Thanks to each of you for responding. Very much appreciated.

8mmFan

[PNW_Steve]

I hope I didn't screw this up...........

I put a patch about 1" forward of the chamber then poured low temp alloy through the chamber.

Then tapped the cast out with a cleaning rod from the muzzle end.

[8mmFan]

And, as often happens, another thought just came to me. ASSUMING that the most relevant measure for accuracy is in the last 6-10 inches of the bore (and I’m open to being taught why that’s not the case, just by the way), why wouldn’t we pound the slug about 8-10 inches down the bore FROM THE MUZZLE, and then pound it back out again from the breech end?

That would avoid getting a reading, as DAFzipper alluded to, above, of a small diameter somewhere above the last 10 inches or so of rifling.

Just a question, with the purpose of determining the most relevant bore/groove diameter.

8mmFan

[JSnover]

And, as often happens, another thought just came to me. ASSUMING that the most relevant measure for accuracy is in the last 6-10 inches of the bore (and I’m open to being taught why that’s not the case, just by the way), why wouldn’t we pound the slug about 8-10 inches down the bore FROM THE MUZZLE, and then pound it back out again from the breech end?


8mmFan
I like to feel the length of the bore for roughness or tight/loose spots.

[mehavey]

Always start from the muzzle since...

- Pounding slightly oversize lead ball into the muzzle with a rawhide/plastic/wooden hammer is a very clean/straightforward process.
- Pushing that ball further down the bore using a short starter and/or wooden [gasp] dowel is again very controllable/straightforward. **
- Pushing all the way through w/ a wooden dowel has never been [should never be] particularly difficult at all **
- "General" bore conditions/groove-diameter/tight spots/are what I'm looking for. Muzzle start is fine for that. I'll be sizing 0.002" over [I]smallest groove anyway.

**
Did I mention really clean/oiled bore & lubed ball ? [smilie=w:
'
-

[Dusty Bannister]

A wood dowel may split and stick in the barrel so is not a reliable method of slugging the barrel. Sometimes you just have to use the right tool for the job.

[canyon-ghost]

Having done this on short barreled revolvers, I assure you the muzzle is tightest. The slug should be easier to push through to the breech. Reversing direction might just stick the slug in place. Come to think of it, my rifle was much the same. Yes, as soon as I tried reversing direction in the bore, I found the slug would jam tight.

Ron

[canyon-ghost]

I used a 1 /4" steel dowel and made a centered indention in the slug. Then I wrapped tape around the dowel a few inches back. Wrapped the tape over itself until it was just the diameter needed to guide the rod without undue pressure. The slug will usually fall out of the chamber.

[popper]

Or just use a VERY small charge of powder and recover bullet a few feet from the barrel.

[mdi]

I like to feel the length of the bore for roughness or tight/loose spots.

Yes^. Since your cast bullets will be .002"+ over groove diameter, plus obturation, that will alleviate any problems from a slightly larger diameter at the muzzle end. Tight and or rough spots in the barrel are easily noticed when slugging. I started slugging barrels of revolvers (a bit more difficult than rifles or semi-autos) and just "habit" now. I have slugged a couple semi-auto barrels from the chamber end, but I did get slug shaving from a sharp chamber end or blunt rifling start...

[blackthorn]

If/when I feel the need to really understand what is going on within the confines of a barrel, I drive a slug from the muzzle in about 3 or 4 inches and drive it back out from the breech end. Then I do the same process from the breech, followed by a third slug driven completely through the full length of the bore. This gives me a complete snapshot of the interior of the bore. A chamber cast (using one of the several methods available) completes a full set of dimensions to work with.

[mehavey]

A wood dowel may split and stick in the barrelIf pushing the slug through the barrel -- both slug & barrel cleaned/lubed -- is so difficult that it splits hardwood dowel, you've bigger problems,
It should push through smoothly, and the lead should not be so hard as to not deform easily.
But if things get hung up beyond that, switch to your steel or composite cleaning rod at that point.

ps: steel rod isn't going harm/scratch or gouge anything.

[charlie b]

For me the most important part of this is the length of throat and dimensions of the barrel where the bullet is chambered.

I push the slug in from the chamber just far enough to get a good 'imprint' of the chamber throat and at least the first 1/4" of rifling (1/2" better). The 'push rod' is steel with tape wrap to center it in the chamber. Then I tap it back out (steel cleaning rod with flat tip jag, wrap with tape to center it and use a muzzle guide).

[Mk42gunner]

Reading about some one using a wooden dowel to slug a barrel flat out gives me the willies. Here's why:

Some time in 1988 the ship I was on was in the yards for regular overhaul. We had put most of our small arms in lay-up since they weren't going to be used. When it came time to take them out of lay-up my striker and I were busy cleaning guns for a few days.

The Navy in its infinite wisdom (Yeah, right) called for using a wooden cleaning rod for 12 gauge shotguns. As I remember they were a 5/8" dowel with a slot for patches and a hole in one end to frustrate you into thinking you could use a bore brush.

Anyway, one of us got a stuck in one of the riot guns barrel. In attempting to get it out the dowel splintered and broke. It took us all afternoon to get the tight fitting patches and splintered rod out of the bore without harming anything except the already broken dowel.

The next day we found that using a .30 cal steel rod and a square M-60 receiver brush did a whole lot better job scrubbing the inside of a 12 gauge barrel.

Since then the only thing I will do with a wooden ram rod is load a muzzle loader. And truthfully if I can get a composite or fiberglass rod I would rather use one of them.

Robert

[mehavey]

Every time I hear "wooden rod splintered" it was someone who forced things beyond the point of failure.
Which is usually, really, really rather tough to do.
But people are stubborn.

Slugging shouldn't require any more force than that of a tight-fitting patched ball.
"Smoothly stiff" in smacking down tight PB is a term I've used to describe that feel for 50 years.
And while I now use unbreakable/fiberglass/nylon range rod, wood with a cartridge case over end served for 25-30 of those years.

[Dusty Bannister]

The OP did mention that he was slugging a Brazilian Mauser rifle. The questions were asked as if he had never done the process before. It would be likely that the bore was not pristine and if he ran into trouble may not realize the consequences of bumping the rod just a little harder. Some of the wood products these days are clearly of marginal quality. It seemed a prudent suggestion to avoid finding himself with a broken and jammed dowel in the rifle barrel. Some may disagree.

[mehavey]

In that case...
- From the muzzle
- barrel totally clean as possible/heavily lubed (motor oil)
- ball lubed
- rawhide/plastic/wooden hammer to the ball/shaving off a relatively-thick ring of lead not unlike a c&p revolver
- short 6" steel section rod to start down first several inches (light hammer again)
- long steel rod (or sections) to push through/out chamber (light hammer again if required)

Pure/soft lead will go through.
Whole lot simpler than it writes up

[8mmFan]

It’s true: I have never slugged a barrel up to now. Mainly just because I’ve experienced fair-to-good results shooting cast, thus far in a relatively short cast boolit career.

But this Brazilian mauser has the worst looking bore of any firearm I own, and it shoots poorly, with both cast and jacketed bullets. After reading a number of posts on These old Brazilians here and elsewhere, I suspect that this rifle’s bore is probably quite a bit larger than .284.

After I get a lead slug and measure it, if it is, indeed, significantly larger than .284, I plan to order a mold that will fit it. The reason is that this is a very pretty little rifle, and I like the way it handles. I can see taking it on easy trips for deer, etc. Otherwise, I’d just sell the rifle. But if I can get it to shoot I’d like to use it and then pass it down to a kid or grandkid, along with the boolit & recipe that it shoots well.

Thanks for all of the info, guys. Good stuff, and it is helpful.

8mmFan

[charlie b]

If it won't shoot well consider having it bored out to .30 or 8mm.