Reaming Formed Brass Necks?

[DonMountain]

I am attempting to form 43 Spanish cases out of new Winchester 338 Win Mag cases by lathe turning off the belts, adding an E-clip to make the base flange work correctly through the gun, and fire forming them in the rifle. I am ending up with the necks too thick to load proper sized lead projectiles and need to somehow ream the necks down several thousandths of an inch. What tools might I use to perform this operation? I have both Pacific and Forster case trimmers.

[ascast]

I was going to suggest the Forster trimmer, but I don't think 348 will fit in the collet holder. Better call them.

[tdoor4570]

In a forester trimmer the 348 win takes a #4 collet to hold the brass. don't know what the dia. of the boolit that you need, give me the dia that you need and I will look on the forester chart

[country gent]

Reamers are available by the .001" from most tool supply shops. Figure what you need they arnt tat expensive. A hand reamer will do the job. A spiral flute reamer gives a better finish and cleaner cut do to the shearing action.

I prefer to support the neck while reaming Make up or modify a die and ream thru with the reamer of choice. Make up or modify a die make it longer than the neck by 1"-1 1/2" and ream thru with the reamer. This keeps the neck from stretching around the reamer and hlds the case. It also supports the reamer straight and centered.

Run case into the die with press and run reamer thru top of die turning by hand.

[country gent]

If you have the collet for 338 ream the necks before adding the clip.

[SOFMatchstaff]

You have a lathe, use a chucking reamer of the determined proper size . I full length size with out the expander and set the ID and wall thickness with the reamer. I made a bunch of 8mm Kurz this way. the reamers are about $20 +- and can be ordered in .001 increments as noted by C Gent. Much easier in the lathe.

[garandsrus]

Check this out for lathe turning necks: https://www.accurateshooter.com/technical-articles/neck-turning-with-lathe/

[gpidaho]

Don: I was having trouble with the necks expanding as mentioned above when reaming necks. I went the other route and neck turned instead. Gp

[DonMountain]

In a forester trimmer the 348 win takes a #4 collet to hold the brass. don't know what the dia. of the boolit that you need, give me the dia that you need and I will look on the forester chart

I have a #4 collet I bought many years ago but I don't think I have ever had it mounted in the case trimmer. The boolit diameter is sized to 0.439" to fit the barrel and chamber.

[tdoor4570]

the closest the chart shows is .4340 for an inside neck reamer , You might give forester products a call at 815-493-6380 and talk with them .

[BP Dave]

A .338 neck expanded to .439 (usual diameter for .43 Spanish) would not ordinarily be too thick.
What type of rifle are you shooting and what size bullet?
--DJ

[DonMountain]

You have a lathe, use a chucking reamer of the determined proper size . I full length size with out the expander and set the ID and wall thickness with the reamer. I made a bunch of 8mm Kurz this way. the reamers are about $20 +- and can be ordered in .001 increments as noted by C Gent. Much easier in the lathe.

And where might I purchase a 0.439" chucking reamer for $20? I looked at Granger, where I have purchased some of these sorts of tools and they are about $60+?

[BP Dave]

And where might I purchase a 0.439" chucking reamer for $20? I looked at Granger, where I have purchased some of these sorts of tools and they are about $60+?

Ebay--you might have to wait and watch for a bit, but they come up regularly.

[DonMountain]

A .338 neck expanded to .439 (usual diameter for .43 Spanish) would not ordinarily be too thick.
What type of rifle are you shooting and what size bullet?
--DJ

I am shooting them in a #1 (Black Powder Action) Remington Rolling Block that appears to have a really clean barrel and chamber without much wear. I am shooting an RCBS 370 43, a mold they custom made for me after I sent them slugs of my bore after purchasing one from them that was way undersized. I think they now sell this mold as their "43 Spanish mold".

[BP Dave]

I am shooting them in a #1 (Black Powder Action) Remington Rolling Block that appears to have a really clean barrel and chamber without much wear. I am shooting an RCBS 370 43, a mold they custom made for me after I sent them slugs of my bore after purchasing one from them that was way undersized. I think they now sell this mold as their "43 Spanish mold".

Do you size it to .439 or shoot it as cast?

[DonMountain]

the closest the chart shows is .4340 for an inside neck reamer , You might give forester products a call at 815-493-6380 and talk with them .

There is the possibility of after fire forming the converted 338 Win Mag case to the 43 Spanish chamber, I could use a 44 Mag die to size just the neck back down so that I could use the "standard" 44 Mag reamer that Forster sells as their 0.429" reamer. And then, after reaming, fire-form the case back out again to the 43 Spanish chamber. When cut to length, the case has what appears as about 0.15" of the original 338 Win Mag neck in the 43 Spanish case neck, and the rest of the neck length is reformed shoulder. Of course I will probably need to anneal it after the reaming again. I have annealed the cases after fire-forming them initially so I am set up to do that. I have also converted some 348 Winchester cases as part of this project to compare the two case conversion procedures, and the converted 348's have been performing very well in the gun. But the necks of the 348 cases are about 0.008" smaller in diameter than the converted 338 Win Mag cases and fit in the chamber of the rifle easily. And fire pretty well, even with their slightly thin base flange.

[DonMountain]

Do you size it to .439 or shoot it as cast?

I am sizing the RCBS boolets to 0.439" as originally suggested by RCBS when they made my mold. I am using an RCBS 0.439" sizer in an RCBS LAM-II. When all this developed maybe 25 or 30 years ago, I worked with one of their technicians to make this work, as they were just developing the mold for a 43 Spanish, and I just happened to have one with a really good barrel. If I remember correctly, they even cut the sizing die to fit my bore correctly. I just went up and measured a sized boolet with a Starret 1" micrometer and it measures 0.440".

[ndnchf]

If you are already lathe turning them, why not just turn the neck thinner too? I was doing this recently to make cases for a rifle converted from 44 rimfire to centerfire. I made a video showing how I did it.

https://youtu.be/iVzb4WopeAM