slugging a barrel

[Sasquatch-1]

Everybody talks about it, but what is the correct way to slug a barrel?

[Carrier]

Don’t know if I do it the correct way but last one I did was my 1873 trapdoor. Sprayed Ballistol in the barrel, used a Hornady .50 cal soft round ball, tapped it in with a soft dead blow hammer and finished with a 3/8” hardwood dowel.

[Outpost75]

Read the sticky.

[LAGS]

When I slug a barrel.
First I slug the barrel from the chamber end.
I insert the lead onto the chamber and pound the slug all the way thru the bore.
Next.
I insert the lead in the chamber and only pound it about 1/3 down the barrel.
Then pound the slug back out the chamber end.
Then the third slugging I pound the slug in from the muzzle end.
And again I only pound it down the bore about 3 to 4 inches.
Then pound the slug out from the chamber end.
This gives you a comparison of if the bore is consistant.
The first slugging thru the length of the bore gives you an idea on how the slug comes out as if the gun was fired.
The second slugging shows the condition of the rifling just ahead of the chamber.
The last slugging shows if the last inches of the bore are worn or rusted.
Now you can see if there is a problem that may be causing issues like bad spots in the length of the bore.

[deltaenterprizes]

When I slug a barrel.
First I slug the barrel from the chamber end.
I insert the lead onto the chamber and pound the slug all the way thru the bore.
Next.
I insert the lead in the chamber and only pound it about 1/3 down the barrel.
Then pound the slug back out the chamber end.
Then the third slugging I pound the slug in from the muzzle end.
And again I only pound it down the bore about 3 to 4 inches.
Then pound the slug out from the chamber end.
This gives you a comparison of if the bore is consistant.
The first slugging thru the length of the bore gives you an idea on how the slug comes out as if the gun was fired.
The second slugging shows the condition of the rifling just ahead of the chamber.
The last slugging shows if the last inches of the bore are worn or rusted.
Now you can see if there is a problem that may be causing issues like bad spots in the length of the bore.

Very good procedure!

[Spoonz]

I cast up some soft lead round balls and used a 6” wooden dowel rod to get them started, drove mine from muzzle to the breach and again used a wooden dowel. I recommend using a rubber hammer incase you don’t have the best had-eye coordination.

[contender1]

"When I slug a barrel.
First I slug the barrel from the chamber end.
I insert the lead onto the chamber and pound the slug all the way thru the bore.
Next.
I insert the lead in the chamber and only pound it about 1/3 down the barrel.
Then pound the slug back out the chamber end.
Then the third slugging I pound the slug in from the muzzle end.
And again I only pound it down the bore about 3 to 4 inches.
Then pound the slug out from the chamber end.
This gives you a comparison of if the bore is consistant.
The first slugging thru the length of the bore gives you an idea on how the slug comes out as if the gun was fired.
The second slugging shows the condition of the rifling just ahead of the chamber.
The last slugging shows if the last inches of the bore are worn or rusted.
Now you can see if there is a problem that may be causing issues like bad spots in the length of the bore."

This is fine IF,, IF,, you can go at it from the chamber end. A lot of handguns designs prevent this.
If you don't have any pure lead balls, ,, the size you need,, find a pure lead "egg" sinker for fishing to use as bore slugs.

[LAGS]

@ contender1.
You are so correct.
But since a handgun does not have a long barrel , where identifying a problem in the bore matters.
But if I need to find true measurements like the forcing cone on a revolver , I do a chamber casting at the cone area with Cerosafe.

[John Taylor]

When I rifle barrels I usually check them several times to see how things are going. Most of the time I use a round lead ball that will fit in the bore and slide a brass rod in from each end and pound the ball to expand it. then drive it out and measure with a micrometer. This is for a cut rifled barrel.

[MrWolf]

If you don't have any round balls or sinkers to use, pour some lead in a fired brass case and smack it down some.

[Sasquatch-1]

When I originally posted this, I should have mentioned that I was mostly interested in revolvers. I have always felt that driving the lead from the muzzle to the breech would not be as accurate as the other way around. I have seen the "two brass rod" method used but was wondering if that would be the best way short of a casting.

So, I guess I should have titled this, "The best way to slug a revolver barrel."

[contender1]

As noted above,, you can do a "chamber cast" of the rear portion of the barrel on a revolver using Cerrosafe. And yes,, we all have to do the slugging where we start from the muzzle end.
Soft driving materials are your friends. Brass rods,, wooden dowels, and very closely sized pure lead slug.

[JSnover]

Just a thought... Would it be possible to cast your slug around a jag or a brush? Insert the threaded end of the brush into the forcing cone? Put a cleaning rod in from the muzzle and thread it together, with a heavy cylindrical weight of some sort (a big nut and some washers)? Now you have a little slide hammer to pull the slug through from the chamber end.
On second thought, maybe not. Most cleaning rods are pretty small, if the threaded end pulls off you'll have a new problem.

[LAGS]

I have made a sort of lapping tool out of an old bore brush and epoxy.
I put release agent in the bore and inserted the bore brush into a plugged barrel covered with bedding compound or JB Weld in the end of the barrel.
Don't use softer 5 minute epoxy except to try and get a bore casting.
It is just too soft.
Once the epoxy set up , I drove the plug out the end of the barrel from the chamber end.
The plug with the rifling cast into it worked to lightly polish out the barrel using metal polish and a cleaning rod.
The same method will work to do a bore casting to get an idea on what the bore looks like inside.
The lapping slug works good since the slug follows the rifling down the bore as it is polished without skipping over the lands and grooves and rounding off the rifling.
And that casting fits your rifling.
But I don't think that doing a casting with lead or Cerosafe will be strong enough to be driven down the bore to get a bore impression if used on a standard cleaning rod.
I have been tempted to mix something like Aluminium oxide powder into the epoxy to cast a polishing slug.

[flybyjohn]

Just something to think about. Yesterday I decided to hand lap a very rough rp9 pistol barrel because I had nothing to loose. I decided to slug, lap, slug, lap and so on just to measure my progress and make sure I didn't go too big and not be able to chamber a round. My process was to pour lead into a spent 9mm case with a dead primer put in upside down to seal the bottom of the case. I then used a kinetic bullet puller to pop the lead out of the case and used this upside down in another 9mm case that the bottom was cut off for a sleeve in the chamber. This created a nice taper for the lead to start into the bore. I measured the lead before just to make sure it was larger than what the measurement would be after it passed through the bore.

This is where things got interesting. I normally pound the lead through the bore and let it drop out of a hole in a piece of wood under the barrel. I normally use a hammer and punch. This time I used a dead blow hammer and after the slug made it to near the muzzle of the barrel, I held the barrel in my hand and just continued to pound in the air until the slug popped out. I did this the same way every time I lapped a bit to keep an eye on material removal. I finally got to the last lap and progress was good with very little removal. I slugged the bore and saw that I had gone from .3556 to .3573 on the finest grit that I used. Aw CRAP, that can't be right.

What I had done after the last time I lapped was that I used a regular hammer. I think that with the harder hitting impact while the barrel was being held in my hand unsupported and the unsupported sides of the slug protruding out of the muzzle, caused the slug to swell up before it dropped from the barrel. I re-slugged with the dead blow hammer after almost crying after reading the micrometer and that slug measured .35565.

So just a note that I think the way the barrel is slugged may make a difference in your reading. I thing the best way is to keep the barrel supported for the full travel of the slug and maybe the impact force or mallet density might make a difference. The lead I used to slug was soft enough to deform just from inertia.

[sparky45]

Excellent observation John; thanks for posting.