1873 Winchester "slugging the barrel"

[Deadeye Dick]

I just ordered a new Uberti 1873 Winchester in 44-40. I would like to slug the barrel in order to be sure I'm using the right bullet dia. I've always heard that one should push the slug through from the breech end. I'm not sure how you would do that since there is no straight shot to push a rod through from the breech. I assume in a case like this it would be okay to push the slug through from the front of the barrel. What say you that are in the know? Is there any difference which end you start the slug from? I'm open to all input.
Deadeye Dick

[Pettifogger]

The main reason for starting from the breach end is because it is easier to start the slug.  Once started into the bore, it doesn't make any difference which end it was started from or which end it exits.

[Driftwood Johnson]

Howdy

You cannot slug a '73, 66', or Henry from the chamber unless you take the gun completely apart. If you were to do this you could perhaps insert your rod through the hole where the bolt goes through the frame, but you would need a narrow rod. A '92 would be easier, if you dismantled the gun you could lay a rod in the relatively wide opening where the bolt was. A Marlin is relatively simple to slug from the chamber, since the bolt can be removed very easily, allowing complete access to the chamber.

I slug all my lever guns from the muzzle, it is much easier than disassembling them. You also cannot slug a revolver from anywhere but the muzzle, no way to run a rod the other way.

Slugging determines the narrowest diameter of the rifling grooves. The slug is relatively soft lead and will only record the narrowest section. With a new rifle this is not a concern, the rifling should be the same diameter all the way through. Some Sharps rifles are 'choked' in slightly near the muzzle, so slugging from the muzzle will only record the diameter at the muzzle.  But a Sharps is easy to slug from the chamber.

With older rifles, particularly if there is wear or erosion near the chamber, when slugged from the muzzle the slug may start sliding through the bore where the erosion exists. I have a couple of 100 year old lever guns, and when I slugged them from the muzzle the slug started sliding freely down near the chambers. This is fairly common with old guns from the Black Powder era that may have some erosion of the bore down near the chamber.

But with a brand new Uberti '73 just slug it from the muzzle. It will be consistant all the way down. If it is not, you will feel it as you batter the slug down the bore, it might start sliding with different resistance at some point. But I would not worry about it with a new gun, I would simply start at the muzzle and run the slug all the way through.

Remember - don't whack the muzzle!

[Deadeye Dick]

Thanks Pard's appreciate the info. I have a bunch of .429 big lube bullets that fit my RM 44 Colt. Was hoping the would work in the new 73. Guess I will find out after I slug the barrel.
Deadeye Dick

[Driftwood Johnson]

Howdy Again

From what I've heard, most Uberti 44-40 rifles seem to be coming through with .429 rifling groove diameters these days, but you will only know for sure after you slug it. My '73 is an older one, it slugged out at .427. But it was made back in the 1980s. The Henry that I bought a couple of years ago slugged out at .429.

You can probably use those Big Lube bullets as your slug, I used a bunch of J/P 45-200 Big Lube bullets to slug some 45 Colt pistols the other day. As long as they are reasonably soft, they will work fine. The lead will probably collapse a bit into the crimp groove and the Big Lube groove, but I had enough bearing surface to slug some barrels with the Big Lube bullets the other day.

Make sure when you measure your slug that there are actual drag marks on the raised portion of the slug. You will see drag marks running the length of the slug on the low points, representing the lands of the rifling. Make sure you see similar drak marks on the high spots, representing the grooves. If you do not see drag marks, the lead may not have completely filled the grooves, and your slug measurement will not be an accurate representation of your rifling grooves. Hopefully, enough lead will be displaced from the land part of the rifling to smoosh over into the grooves and completely fill them up.

If you don't see drag marks, you cannot be sure the slug is an accurate representation of your rifling.

Here are a couple of photos to illustrate. This photo shows the J/P 45-200 bullets I was using to slug some 45 barrels. At the top is a J/P 45-200 as cast, then you can see how it gets deformed as it is forced through the barrel.



In this photo, the arrow on the slug at the top points to good drag marks on the high points of the slug, indicating that the rifling was completely filled with lead, and measuring the slug will give a good measurement of the diameter of the rifling. On the slug at the bottom of the photo the arrow points to the same spot on the slug, but there are no drag marks, indicating that the lead did not completely fill the groove. So that particular spot on the slug will not give an accurate measurement of the rifling groove diameter.



Now, it must be said there is more than one way to rifle a barrel. These barrels were rifled by dragging a tool through the barrel after the original hole was bored. Dragging the tool left tool marks running the length of the grooves, and the drag marks on the slug were created by the tool marks in the rifling. Some methods will not produce tool marks like this, or they may have been lapped out. But most barrels I have peered down have tool marks that will leave behind drag marks on the slug, once the lead has completely filled the rifling. If you peer down the bore with a bright light, you will see these tooling marks.

[Deadeye Dick]

Thanks DJ,
Someone mentioned using pure lead sinkers. Will try the bullets first.
Do you use pistol or rifle primers in your reloads? I plan on purchasing a revolver in 44-40 down the road aways and I want to be able to use the same reloads in both. I plan to load with black powder so the powder amount will be the same.
Deadeye Dick

[Driftwood Johnson]

Howdy Again

Although it was originally a rifle cartridge, ALWAYS use Large Pistol primers when loading 44-40. Do not use Rifle primers. Rifle primers can run a little bit taller than pistol primers, and the primer pockets in 44-40 brass are cut for pistol primers. Using rifle primers could result in high primers. And rifle primers usually have a harder cup, so you might have trouble firing a rifle primer in a handgun with a light hammer spring.

Use Large Pistol primers.

[Deadeye Dick]

DJ,
Large pistol primers. Got it. Thanks!
Deadeye Dick

[Deadeye Dick]

Received the rifle yesterday. Slugged the barrel and it came out .429. Loaded up the 44-40 brass with some .429 Big Lube bullets using  a 2.2 cc dipper load 3f Swiss black powder. They shoot fantastic. Sighted it in and am taking it deer hunting tomorrow. Thanks DJ and Pettifogger for your assistance.
I am one happy camper. 
Deadeye Dick

[Steel Horse Bailey]

Happy Hunting!