Noob needs help 38-70

[Shell knob]

Just slugged barrel on new to me old Winchester 1886 in 38-70. With dial calipers and digital calipers I get .3855, and .386 on digital. I have a mold from Accurate that drops a .380 260ish gr. bullet for a 38-55. I’m not sure I’d be able to chamber a loaded round that’s sized to fit groove. My options before buying mold. Shoot soft lead w black, maybe it’ll bump up. Inside neck ream. Try patching a grease bullet. Am I forgetting anything else? Thanks in advance.

[Wayne Smith]

Don't just slug the barrel, do a chamber cast - then you know exactly what you have for a throat and chamber. On the other hand, I have no idea how hard it is to chamber cast an 1886!

[Shell knob]

I do have a chunk of cerrosafe.never having used it before, would a funnel made of tinfoil work to get liquid into chamber?

[Nobade]

I have a funnel made out of a 300 Weatherby case that works well for doing exactly that.

I doubt you'll be able to chamber a cartridge with a bullet that big seated, so as you surmised, pure lead and a full charge of black powder will probably be your best path forward.

[gc45]

Why not chamber your cast bullet and case to find out? Many old Win will take a .002 over dia bullet with ease so try one first and if it won't chamber get another mold. I shoot .380 cast in my antique 38-55 with no issues. Keep in mind these old rifles were not near as perfect in their sizes as modern guns and having measured many over the years I have found quite a few have larger groove dia. than what is published spec and their chambers will also take a larger dia. boolit. Of course the chamber size rules here and why cerrosafe is a good idea. Cerrosafe is easy to use, melts quickly and pours easily. Getting it into the chamber can be an issue for lever guns so I used tinfoil making a boat shape sort of to pour it in. Be sure to plug the barrel just in from of the chamber, a tight wad of cotton works pretty well and also a buffer when pushing the stuff back and out of the chamber; I use a long dowel that is just smaller than the bore dia. and tap, tap, tap. remember to not pour in to much, just enough to fill about 3/4 of the chamber is all, works for me. I also put a rag into the action so any spillage is caught keeping it out of the working parts.

[Rockindaddy]

I am an old cast boolit shooter. Have several original 1886's that shoot like they have eyes! You will need a .386 ~ .388" lubed and sized boolit to get that ole lever gun to shoot! Don't waste your time with that Accurate .380 boolit. If you have a Starret expandable ID gauge or borrow one, you can measure the chamber neck diameter. A Cerosafe casting would be good also. Have reamed several chamber necks to allow for a groove diameter boolit to be seated in a case and chambered. My 1881 Marlin is 40-60 Similar to 40-65 Win Had to ream the chamber neck to make the ole gal shoot!

[Mk42gunner]

Since cerrosafe isn't all that hot even when molten, I think a funnel made from aluminum foil will be fine. I would almost bet you use a funnel made from heavy paper.

A top eject lever action has to be one of the easiest styles of rifle to do a chamber cast in, lots of easy access. Just don't pour too much or too fast.

Robert

[Shell knob]

All great ideas. Can’t wait to get started on this. Thankyou again.

[Wayne Smith]

Let us know how it comes out!

[Shell knob]

Update. Got dies from CH tool. Took stems out and cleaned all three. Grabbed a 45-90 piece of brass that had been sized to 40-82 and ran thru sizer, all good. Then expanded the neck until there was slight flair on cartridge mouth. Next tried seater. First problem. I couldn’t screw the stem down enough to seat bullet. I had about 1/2in threads left to screw in, but no go. Pulled seating stem had to clean threads, used Kroil and kept working stem until I got all but 2 threads left to screw in. Then tried seating bullet. The expander isn’t big enough to allow bullet to seat my soft bullet without leaving ring on bullet nose. Checking w caliper I’ve got .003 difference from where the bullet is seated in the case to just below the bullet on the case. Was going to turn a new expander today that goes deeper into case, but it’s snowing this am, and my lathe is out in unseated barn