I'm reforming 223 brass to 221 Fireball.

The outside neck diameter measures .007" - .008" larger on the reformed brass than on the factory brass after they've been put through the FL size die. This prevents the brass from being chambered in my rifle. I need to trim the neck thickness via outside neck turning and I need to buy the tool to do it.

What are the pros and cons of different tools on the market?

Best and smoothest costs most. That, according to Glen Zediker, is the outside neck turning cutter on the Gracey case trimmer. Next best seems to be the electric screwdriver approach. Sinclair sells a threaded screwdriver adapter with a small hemispherical tip in the center. Special case adapters screw onto it to hold the case, and the hemisphere centers the case by pushing into its primer pocket when you tighten the adapter down. You then use the screwdriver to feed the case into a hand held neck turning tool. That saves time over turning entirely by hand with what resembles a tap wrench holding the case. My only gripe with the system is the inside threads on a couple of the adapters I got were not concentric with the adapter axis when put together, so the case wobbled. I wound up single-point turning the adapters in my lathe to get rid of the wobble.

In all instances, you need an inside neck lube to turn over the mandrel. Whether dry is good enough or you need to go to STP or something else wet just depends on how many turns the case makes and how fast. Try both to determine best results. I just use motor mica or Imperial neck lube (graphite powder), and refresh it if I think I feel drag.

As to the hand tools themselves, they are similar looking. You get a handle which hold mandrels that the case slides over, and an adjustable cutter you set up to provide the desired amount of trim between the cutter and the mandrel. On the Sinclair tool you can do this with a shim between the mandrel and the cutter. They also make a dial indicator optional attachment to help with the setup.

The most interesting idea in the cutter adjustment arena is, I think, on K&M's outside neck turning tool. It uses an in-line screw adjustment rather than just a set screw on the cutter. The screw is really two screws, the outer being bored and threaded for the inner. This provides concentric threads with slightly different pitches to adjust the cutter. As you turn the adjustment, the coarser outer thread moves the cutter down, while the finer inner one pulls it up. The result is you adjust at a rate equal to the difference in the two thread pitches, which is small. This allows them to give you adjustments with ten thousandths of an inch graduations that you can see easily and that let you fine tune the cut to exactly what you want. If I had not bought the Sinclair first, I would have bought the K&M for that feature, but have never actually used one. I will say that Sinclair's cutter's tip shape gives clean, chatter-free results. I would expect the K&M to do that, too. I use K&M's benchrest primer seater, and it is top notch.

Unclenick - thanks for your input, help me to better understand this.

This is the "Basic System" - Are the Lee Auto Prime Shell Holders different than the ones that come with the Lee Case Length Trimmer and Lock Stud?

http://img.photobucket.com/albums/v69/GuideGun/KMProd8.jpg

K&M description - Undoubtedly the tool with the best resolution of adjustment of all tools on the market. Outside neck turning (hand lathe) is far superior to any form of inside reaming as a reamer would tend to follow the off center hole. The K & M tool is simple to use, it can easily be adjusted to remove the desired amount of brass from the thick side to clean up and equal the thin side or the tool can be adjusted to cut down to the desired dimension. Tolerance can be held to .0001” very easily – the adjustment is compound thread that is equal to 440 turns to the inch instead of the usual 40. (Note – even a micrometer only has 40 turns to the inch.) Index marks are provided to assist its adjustment. Special ground with angles unique to cutting brass. The case holder uses Lee auto prime shell holders for the different calibers. The shell holder clamps the case in the hex drive power adapter so it can be powered by a low speed drill or cordless screwdriver, or the power adapter can be put into a handle (provided) to be hand operated

This is the "Pilot Jack" but it is not clear to me how to use it.

http://img.photobucket.com/albums/v69/GuideGun/KMPJACK320copy.jpg

K&M description - The K & M Expandiron is required for proper final neck expansion. Virgin competition brass isn’t quite ready to neck turn when you buy it and the commercial die manufacturers have no set standard for the Expander Button in their Die. Large variations from manufacturer to manufacturer and even within a given manufacturer makes it necessary to properly "size" the inside diameter before turning. Don’t be fooled by slick talk. The turning pilot cannot be used to correctly expand the neck because of the brass elasticity it will "spring" back and be too tight to properly turn the neck. The 7/8-14 adapter fits your normal press and the Expandirons are sized to be the perfect companion to the K & M Microadjustable Neck Turner. Smoothes "out" and slightly expands the case neck so the brass will spring back to the correct size needed to neck turn your brass. Each Expandiron has an adjustment screw to bottom out in the brass before the case mouth could hit the mandrel shoulder.

This seems like a good thing to pick up too. They say it is adjustable (not that I can see in the photo) and I wonder if it will work with a Fireball case.

http://img.photobucket.com/albums/v69/GuideGun/Kmexdie.jpg

http://img.photobucket.com/albums/v69/GuideGun/KMProd9.jpg

Are the Lee Auto Prime Shell Holders different than the ones that come with the Lee Case Length Trimmer and Lock Stud?


As far as I can tell they're the same in terms of shape of the cutout/slot and so forth, but they're NOT exactly the same because the case length trimmer ones are threaded to screw onto the lock stud, whereas the Auto Prime ones are not. So, yes or no depending upon exactly what you meant. :)

I guess the question is - is one a substitute for the other with regards to the K&M neck tool?

They are completely different. You can buy the complete Auto prime shell holder set for about $16.00, you have to buy the case trimmer holder as a unit caliber specific for about $4.00.

Bsn & MZ5,

Are you guys sure about that? The shell holder and retaining collar for the case turning handle look like the same ones K&M uses on the Markel priming tool. I don't have their neck trimmer, but do have that excellent priming tool, and the Lee holders fit the priming tool. The black collar is threaded and retains the shell holder in concert with the primer ram sleeve that centers it. Are you saying they've threaded the hole in the Autoprime style holder itself? The ones I have are hard enough to make that a nuisance to do, unless they are making their own and doing it before heat treating? I just don't see what purpose the black collar would serve if the shell holder itself were threaded?


Flashhole,

The only inside neck reamer I ever saw that did a fair job of cutting neck walls uniformly was the one that came in the old Lee Zero Error Target loaders that have been discontinued. These were like a fancy Lee Loader for benchrest shooters, and the reamer was used when the case neck was firmly in place inside the neck sizer die. The reamer was sized for a snug fit into the seater hole above the neck (remaining portion of the sizing hole), which acted as its journal while you turned its crank. It would not be as precise as the modern outside turning tools, but got things within half a thousandth or so and took out any sign of the "dreaded donut" that might have formed at the same time.

Sinclair, in addition to their electric screwdriver adapter, also carries a die body and tapered tip mandrels for inside sizing necks for case turning. You buy the size you want. That might solve that issue for you.

Anybody try the LE Wilson inside neck reamers that work with their trimmer base and case holders?

Andy

I saw a Wilson inside reamer advertised on eBay but it did not have the trimmer base and case holder. What is special about the base? I guess I will research it, do they have a website?

The inside reamers aren't good for thinning necks (except the obsolete Lee tool I mentioned, and even it has a half thousandth or so wobble) because the case necks are unsupported during the reaming. This allows the reamer to self-center in the existing neck hole, deflecting the outside which ever way it needs to so it may occupy that center. Thus, it does not elimenate uneven neck wall thickness, but rather leaves it as you found it.

The purpose of the inside neck reamers is to elimenate the "dreaded donut" of brass that has flowed into the corner of the shoulder and neck during the conventional push-back resizing motion. When you push the brass back to size, the extra surface area that resulted from being expanded into the chamber has to go somewhere, and that corner is one of the wheres. If your bullets seat into the donut, the added constriction can cause unsafe pressure. Inside neck reaming is usually done after annealing the case neck, when the brass is softest. It is one of the advantages of the Lee Collet Sizer that it does not form the donut.

Relative to other lathe type trimmers, the Wilson seems to support the shell better in a sort of mock chamber (with the neck area cut off, exposing the case neck). While it does not directly support the neck, it does support the cartridge better than those that just grab the base/rim (For instance, there is no pilot on the trimmer). Case holders are usually specific to a base cartridge (i.e. the 243/260/7mm08/308/338fed/358win all use one holder). Some cases with less taper need separate case holders for fired and sized cases.

The Wilson reamer is held in the same bearing setup as the trimmer, you just replace the trimmer with the reamer.

http://www.lewilson.com/

Andy

Big Jake1s,

True. I own and use and like the Wilson trimmer for most of my rifle cases, so I know it well. But if you've done any machining, you'll appreciate that 14 thousandths of brass neck wall coming off an unsupported shoulder is not heavy enough to prevent deflection of a thousandth or two. Add to this that because an uneven neck wall usually is reflected by about twice as much unevenness in the case web thickness behind it, and you'll see why a lot of cases are a slightly eccentric oval in cross-section and have webs that are not quite coaxial with the neck. The neck on such a case won't be held perfectly coaxial in the Wilson holder.

Another trouble maker is the observation by the accuracy crowd that conventional neck expanders can pull necks off axis with the rest of the case as they withdraw from the sizer. Such cases will, again, not have a coaxially located neck in a Wilson holder. Not all chambers are perfectly symmetrical, either, so performing the operation on an un-resized case with an oversize reamer can't guarantee to fix that, either. The angles involved don't matter a whit to trimming, but between deflection and the inability to guarantee perfectly symmetrical case profiles, there is just no way for the Wilson tool reamers to ensure uniform thinning of a case neck.

Unclenick,

Thanks, I was afraid that might be the case (pardon the pun).