How does one obtain consistent results when neck turning

[Campbell]

To all you reloading gurus:-

I have bought the K&M neck turning kit and have used it thus far on about 100 Lapua .308 cases.

After close examination, I can see very fine "lathe" marks on the neck which nevertheless translate to variances on the concentricity gauge.

I use the kit with a cordless drill on high speed and I use WD40 as cutting fluid.

How do you folk obtain the smoothest cuts?

Many thanks in advance

Cam

 

[dkhunt14]

Spin then with steel wool on the necks. Matt

 

[Jet]

Couple suggestions:

- Slow your initial cut speed down a bit for the 1st pass then speed up for the 2nd/3rd pass
- If using a steel cutter replace it with a carbide cutter
- As Matt said above, spin them in steel wool when done. The steel wool will leave a fine dust on the neck so make sure to wipe that off prior to sizing.

Good Shooting

Rich

 

[Grimstod]

Turn them in slow and on the out then use the fastest speed.
WD40 is a lousy cutting fluid. Get an oil that is meant for actual cutting. It will give you the biggest improvement.

 

[rjstubbl]

I spin them using the green scotch bright scouring pads . Cleans them up nice .

 

[jds holler]

I second the motion on good cutting fluid, multiple passes, and I try to go slow enough that my mandrill doesn't get ripping hot. I keep it warm but not uncomfortable to the touch.

I put all my cases through a cleaning boil (with auto dish soap) when done to wash off the cutting fluid. (Rapid Tap). jd

 

[rardoin]

To clarify a couple of things concerning turning....

There are two 'speed' to consider. First is the rotational speed of the case. The faster you spin it the more heat will be generated that will cause thermal expansion of the toolholder and the case (to a much lesser extent). The rotational speed you choose will be a compromise between controlling heat and reducing the time you spend making the cuts. The second speed is the rate that you feed the cutting tool along the neck. The faster you feed if the coarser the surface finish; if your rotational speed is very slow and feed rate high you would be essentially cutting threads. I turn necks at about 150 rpm and feed the tool at a rate that gives a very fine finish which translates to about 4-5 seconds in and then out when turning a neck the length of .308, 6.5 Creedmoor, 6.5 x55. I dip my cutting tool (K&M with the large handle that also serves effectively as a heat transfer sink) in cool water between cases. I am happy with the finish and consistency of the results.

 

[JRS]

To clarify a couple of things concerning turning....

There are two 'speed' to consider. First is the rotational speed of the case. The faster you spin it the more heat will be generated that will cause thermal expansion of the toolholder and the case (to a much lesser extent). The rotational speed you choose will be a compromise between controlling heat and reducing the time you spend making the cuts. The second speed is the rate that you feed the cutting tool along the neck. The faster you feed if the coarser the surface finish; if your rotational speed is very slow and feed rate high you would be essentially cutting threads. I turn necks at about 150 rpm and feed the tool at a rate that gives a very fine finish which translates to about 4-5 seconds in and then out when turning a neck the length of .308, 6.5 Creedmoor, 6.5 x55. I dip my cutting tool (K&M with the large handle that also serves effectively as a heat transfer sink) in cool water between cases. I am happy with the finish and consistency of the results.

Winner winner, chicken dinner

 

[effendude]

I switched from Mobil 1 to chain saw bar oil as my lube on the mandrel and apply a dab on the outside neck of the case as well, Tool never gets warm, cutter gets a little lube too. After turning, I chamfer inside and out and then polish and debur the case mouth and outside of the neck with 0000 steel wool while the case is still in the drill. Can't go wrong with slow speeds.
Scott

 

[Grimstod]

And I forgot to mention heat. As has been well mentioned above it will cause issue. Especially if cutting deep.

 

[savagedasher]

Good lube and a proper angle sharp tool . Along with tool speed . Larry

 

[Pappy42]

The carbide cutter has worked better for me. When making large cuts; make two small cuts instead. I concur with slow speeds. 0000 steel wool works fine for smoothing the necks. I use Imperial die wax to lube the mandrel. YMMV

 

[BenPerfected]

How does one obtain consistent results when neck turning

Ship your brass to DJ Brass Service. If to consider the cost of cases that get cut incorrectly and the time you save, DJ's offers a good value on neck turning and annealing.
Ben

 

[LHSmith]

#1 Most important is to use a carbide MANDREL that is matched to the expander.
#2 Keep everything -brass, neck tool as close to a constant temp as possible -a heat gun will be your best guide until you figure a "system"
#3 Brass does not require any cutting fluid whatsoever, but a touch of high grade oil applied with an oil needler on the mandrel helps
#4 Regulate the feed rate to get the finish you want, cut going in and cut backing out
#5 Spin the neck on steel wool to finish

 

[Campbell]

Good grief

Many thank for the many replies!!

I will digest them later.

Thanks again folks

Cam

 

[Endyo]

Cam,

I played with different speeds, steel wool, lube, etc. These all help, but I was able to get the visible tooling marks resolved by making sure the cutting blade cuts flush to the neck. The rest is icing on the cake.

 

[Mr Underbridge]

Any one here turn by hand?

 

[Willie]

Very good advice above, but in a nutshell, concentrate on:
1. Get several cordless drills that run 150-160 rpms.
2. Use the k&m large heat shrink holder.
3. Lube inside neck with Imperial wax on Q-tip.
4. Expand each case neck immediately prior to turning.
5. Lightly lube mandrel with Imperial wax.
6. Seat case firmly into shell holder, tighten snugly, observe
run-out, re-index case if necessary.
7. Hold Turner on the side that is showing cutter.
8. With very relaxed hold, advance case slowly - watching for a
fine thread or chip. Do not set for a cut over .001".
9. Take your time, I go at same feed rate into shoulder slightly
and out. You must be consistent for consistent results.
10. Spin neck in 0000 steel wool to polish.
11. Use clean Q-tip to remove lube in neck/shoulder completely.
12. Measure 4 sides of neck with ball mic and do the math to see
if clearance desired is right on, adjust cutter as necessary.
13. Repeat, as concisely as possible. Patience and experience
will get you there.

 

[jimbires]

I use a angle drill to turn necks . this drill has a screw through the trigger that regulates the speed . you can see the trigger screw in the pic . I do run it slow . I use RCBS case lube to lube the mandrel . I've never used a cutting fluid on the cutter , I'll have to give it a try next time . I also expand the neck just before the cutting . I only cut a couple at a time , then I let things cool .

 

[M14AMU]

Any one here turn by hand?

Yep! As usual....an old fart doing it right!