Case trimming in the lathe

[yovinny]

I've noticed a few references to people using laths for case trimming.
I'd like to know, what kind of chucking and tooling are you using or have found best ?

I've tried 2 different 3 jaw scroll chucks without much joy.
I've tried a 3 jaw scroll with soft jaws and bored them to fit a particular case, but while it worked better, it has limited interchangeability for other calibers.
I was thinking of using my collet chuck and getting an blank 5C collet to bore with steps (like a forster case trimmer 'chuck') but that would seem to provide very limited case support without also using a piloted type trimmer.

Any info and ideas appreciated, TIA.

Cheers, YV

[country gent]

I think if I was going to use a lathe for trimming small amounts I would set the cutter in the spindle and make a case holder /collet for the carriage. this would save startig and stoping the spindle for every case. For reformed brass where alot needs to come of fixture for a collet fixture to hold on the body and a very thin cut off blade in the carraige to slice of the excess. A cuttoff blade .030 wide or thinner would make short work of trimming 1/4" off . A set of soft faws can be drilled and taped to loch a brass or aluminu jaw set in place. Bore the bushing to hold case and split into 3 ecual sections bolt or glue onto jaws.

[Three44s]

I am no machinist however if I was set on such an endeavor, I'd take a look at the Wilson Tool and Gauge stuff for a starting point.

They make a case holder for specific cartridges and cartridge families and for specific conditions.

Whether it would make economic sense to buy their holder instead of building your own , you can determine after you price them.

(I use several of their holders along with their trimmer body for my more precise cartridge combos, and a Lyman universal for general trimming, if I got more heavy cutting a Harbor Freight mini chop saw would get bought)

Best regards and good shooting!

Three 44s

[bangerjim]

Lathe trimming is very time consuming and a LOT of busy work. I have 5 metal lathes and use the LEE QuckTrim in a single stage press dedicated to trimming instead. Fast and accurate. Trims and chamfers with just a few turns of the handle!

I made a horizontal trimmer last year and have not even used it since I bought the Lee and all the adaptors for the sizes I trim.

I could not imagine spending all that time tightening and untightening a lathe chuck and cranking the carriage around just to trim some brass. Then you have to chamfer it! There are better, much faster, more accurate ways to do it.

banger

[rbuck351]

I use the Lee trimmer with the case holder in the lathe chuck. Once trimmed I deburr while still spinning then shove a empty 12ga shell filled with steel wool on the end of the case and all done. Just takes a few seconds to stick a new case in the holder and repeat.

[yovinny]

Lathe trimming is very time consuming and a LOT of busy work.
I could not imagine spending all that time tightening and untightening a lathe chuck and cranking the carriage around just to trim some brass

Well, thats been pretty much my experience also, besides finding no really good way to hold the cases.

Using the Lee trimmer holder would probably be faster, but even at that, I really dont see how it could be better, faster or easier than just using it set-up in the drill press.

I really want to hear from one of these guys that are always claiming trimming in the lathe is just the end-all bee's knees greatest thing since sliced bread

[GRUMPA]

Even though I have a lathe, that's something that just isn't fast enough, nor accurate enough.

I use custom 3-way trimmers, which pretty much does everything all in 1 shot. Most of the time it takes me longer to put the case in than it does to trim, and I don't care if I'm taking off .100 or more, it goes really fast....

[rbuck351]

For those using a drill press, just think of the lathe as a horizontal drill press and you can see why it's just as fast. You can use a drill chuck in either end or both if you want. I use the Lee case holder in the lathe chuck and the just stuff the lee hand held pilot cutter in the case then deburr and polish all in about 15-20 seconds per case. The Lee case trimmer/pilots are fast and accurate and the case holder is very quick as well, it takes 3-4 seconds to change a case. If I'm forming a bunch of cases that need a lot of length removed say 1/4" or even more, I make rod that fit's the inside of the neck sharpened like a screwdriver so it bites slightly on the inside base of the case, run the live center in the primer pocket and with the cross feed carriage and tool set and locked just part them off for final length trim after sizing. I have a Sears 6x18 benchtop lathe that lives on one of my loading benches. It also makes GH&I dies Star sizer dies, Swag-o-matic dies. GC making dies and a bunch of other stuff. It's a very versatile case trimmer.

[Lead Fred]

Been using an LE Wilson case lathe since 1961

A might cheaper than a machine shop

[bangerjim]

With my press-held Lee trimmer, I can trim AND chamfer (inside and out) a case in 5-8 seconds.....lots faster than any lathe set-up.

At 20 seconds to ONLY trim, that is almost 3 hours to trim 500 cases! And you still have to chamfer them.

My philosophy has always been: use the correct tool and for the purpose it was designed for.
Guess that is why I have ever tool made by man.....and many of my own design.

But do whatever floats your boat.

banger

[Frank46]

I used to use the wilson but now just the lee cutter and lock stud. Just stick in a variable speed drill, trim and chamfer.Frank

[sdcitizen]

I use the lee cutter with appropriate case guage mounted in the headstock, and handle the cases by hand. It only works for primed cases, as the pin on the end of the guage has been shortened to set length off the center of a primer anvil. It is very fast though, can do a 3 gallon bucket of 233 in less that an hour, i would guessan average would be 4 seconds per case, maybe 3 seconds after doing several hundred.

[eagle27]

Many years ago since I trimmed a bunch of 45LC cases down to fit my 455 Webley but I used a big old flat belt driven lathe to do the job. Turned up a spindle to hold in the 3 jaw chuck over which cases would snuggly slip bottoming on the inside web head and held on the spindle using a small tail stock live drive in the primer pocket. Set up a sharp parting tool in the spindle at the right case length and went to it. Didn't take long to trim a hundred or so new cases and I also thinned the rims using exactly the same system to hold the cases but did this as a separate step after setting up another tool in the turret (was not a multi tool turret).

[rondog]

Giraud here, FTW.

[pdgh59]

Has anyone had success in trimming 24 gauge brass down in a lathe to use in a 577 Snider? If so how did you hold the case?

[BigEyeBob]

I use the Lee trimmer with the case holder in the lathe chuck. Once trimmed I deburr while still spinning then shove a empty 12ga shell filled with steel wool on the end of the case and all done. Just takes a few seconds to stick a new case in the holder and repeat.

Thats what I do , and for my odd calibre cases that Lee dont make length gauges for I make my own length gauges ie: 300 Sherwood , 300 Rook etc.
Its pretty fast and takes little time to trim 100 cases

[yovinny]

Giraud here, FTW.

LOL,,,
Yea,, I have a Gracy on the short list, just for rifle calibers I load in bulk. Especially since I learned it also readily uses the better Giraud blades, so total cost even with a Giraud blade is still a C note cheaper for basically the same 'electric pencil sharpener' machine.

I can see using the lathe for specialized jobs, like thinning rims, etc. but otherwise it makes little sense to me. I tried it all sorts of ways without any joy and always went back to the Forster case trimmer and a battery drill...Which I have two of with a ton of pilots, that are paid for and I'll still use for calibers I dont shoot as much.

Cheers, YV

[jmorris]

Depends on the case your trying to trim but soft jaws could be machined to hold the taper with some you could get away with a collet.

I have used a mill before again you can make any shape jaws you want.

not very practical though lots of better and faster ways to do the job.

[Eddie2002]

I've been using a Unimat mini lathe for trimming cases. One of the biggest problems was the fact the 3 jawed chuck would dig into the case and score it up. It would happen with tapered cases like 308 Nato or 30-06. I ended up wrapping the base of the case with a strip of paper about a 1/2 inch wide along with some clear packing tape. By folding the paper over on it's self once or twice along the leading edge I was able to compensate for the case taper. I ended up with a paper/tape sleeve that would be tight on the base of the case but could be slid onto the case from the top. It also protected the cases from scratches or damage. The sleeve also works for rimmed cases, I just make it thicker without a taper.
To trim the cases I use a carbide cutter set a little at an angle and have a stop on the feed bar. It's really accurate and can trim about 2 cases per minute.
I think the reason it works so well is because of it's small size, I don't think trimming cases on a larger lathe wouldn't be feasable.

[Three44s]

I bought a carbide cutter for my Lyman universal trimmer ........ I squalled at the (then) $42 price for it but have never looked back ...... it's fast because it always sharp ........ unlike steel cutters which periodically need resharpening.

I tried a drill press trimmer setup ..... and found it's not accurate to length ........ even my Lyman univ. is not super accurate .........

So when it's time to split hairs, it's the Wilson then.

I bought a used RCBS trimmer with the intention of setting with their 3 way cutter head on often used cailbers but have not gotten the rest of the tooling yet.

Best regards

Three 44s