How to Slug a barrel

[rost495]

My caster would prefer a slug... for barrel diameter, before casting/sizing, gaschecking..

Never done it. Read about it a bit here and there. Fishing weight of close size, driven down barrel... and inch or so. With a tight wood dowel.

Any lube for it to go?

How do I get an 1892 winchester apart to drive it back out of the muzzle then from the back? Never taken one of those apart....

I can assemble an AR15 from the ground up, probably almost blindfolded but and dumb to lever guns.

Links welcome also

Thanks, Jeff

[meanc]

I drive a slug from the muzzle all the way out thru the chamber.

I ran a slug thru the chamber once and out through the muzzle, but there was no difference in the slug, plus it was a lot more work.

I didn't use any lube, as the soft lead was easy enough to get through.

[Andrew]

Get a fishing weight or similar and drive it down the barrel with a wooden dowel. Put some grease on it like bullet lube or just bearing grease.

How to slug a barrel.

[J Miller]

I use the hollow egg shaped sinkers. I've read that they displace well into the cavity and don't spring back like the solid ones do.
Make sure the bore is sanitary clean then lightly oil it. Drive the slug through from the muzzle end and then measure it.
I use a Starrett micrometer that measures down to .0001" and measure all the lands ( the groves reversed ) so I know if the grove diameter is even all the way around.

Joe

[Nate Kiowa Jones]

Here's how I like to slug a bore. I like to use a slug of soft lead that is at least 1 1/2 times long than the bore that's being slugged. This extra length assure that the slug doesn't wobble or try to turn in the bore as it's hammered through. This can be verified with short slugs. Measurements will vary depending on where you measure it. The longer slug yields more consistent results. Make sure the bore is clean lead free and lightly oiled, as in an oiled patch pushed though it.
You can drive the slug in from the muzzle if you use a leather or rubber mallet so as not to damage the crown. I like to drive it all the way through to feel and high spots or bulges. I like to use a brass or hardwood dowel that is close to bore size. A rod that is too small can deform the soft lead. Next if it's a levergun I use two wooden dowels just smaller than the bore and cut to the cartridge OAL. These are inserted into the chamber end and the action closed. Next the slug is re inserted in the muzzle end and driven to the wood dowel then bumped up so it's now tight. Now, open the action, remove the dowels and gently tap the slug on out. This will give you a really true picture of the bore just in front of the chamber or farther out depending on how many dowels are used.
To measure I like to use a zero-ed Starret micrometer. I don't think most dial calipers are accurate enough.

[rost495]

bore has some serious pits, so I guess thats not an issue. The crown should be recut anyway...

Fishing sinker for a 32-20 I'll look for an egg sinker and the right size dowel and oil the barrel and run all the way through then.

Thanks, Jeff

[marlinman93]

I personally don't drive a slug all the way through to get a bore diameter. It is nice to do so, if you want to feel the condition of the entire bore, but it wont tell you much more than that.
I prefer to slug bores from each end. I drive a slug in from the muzzle about 2", and then drive it back from the chamber. I then do the same from the chamber end, and compare the two diameters. Or just send the slugs to your mold maker and a note stating which ball came from which end.
I always use a soft round ball, as used in muzzleloaders, and a bit larger than the bore.

[CowboyTutt]

This is all great information. I just want to add a bit of emphasis on certain points:

The barrel and chamber must be surgically clean as Joe pointed out. Otherwise you will feel bulges or tight spots from carbon build-up that can be very misleading.

I think its important to slug the whole barrel to feel for tight/rough spots as mentioned.

I also think its important to slug both ends. I know of a couple of Puma's that had reverse tapers to the bore!

I ordered up the "Slug your Barrel Kit" from Meister Bullets at Midway and really like it. It was worth the $25 bucks or so as I use it on most of my guns.

-Tutt

[J Miller]

NKJ,

Is there any source for the soft slugs like you describe? Or do you have to make them yourself?

Joe

[marlinman93]

I buy muzzleloader balls from Hornady myself. I keep .45 cal. and .38 cal. That usually does most guns I would be checking.

[Leverluver]

100% ditto for what NKJ said except that I use brass or copper rods of the correct size. Also for the chamber length dowels to put through the action. At one time, I had a business that required slugs be sent to me and I must say 90+% of them were totally worthless and were returned for a second (and final) attempt. Bumping an undersized slug up between rods and then driving them out only a minimal distance better preserves the surface of the lead to be measured. And for accurately measuring slugs, calipers aren't "kind of" worthless; they are totally worthless.

[rost495]

thanks for all the input.

I know it won't do me good to do all the way through. I may do both ends though, of course the muzzle end is most important IMHO.

Jeff