Trouble neck turning with K&M "doughnut" remov

[ecomeat]

Has anyone else had any issues with a K&M neck turner, using the doughnut removing "turning" mandrel ??
I am setting up a new 223 barrel on a old LH Krico match action, for F Standard and F/TR, and I have just FLS'd 200 x new Lapua cases in 223, lubed the inside of the necks properly, then used a Sinclair 22 Cal expander mandrel on all 200, before running 25 or so thru the K&M neck turner.
All 25 cases are scratched (badly scratched, the burr is easily felt) on the inside of the neck, from where the (slightly oversized ??) doughnut cutting head on the tip of the mandrel has worked its way down. Also noted that there are brass shavings inside every case. In some it is curled up and basically still attached to the inside of the neck.....definitely the work of the fancy cutting tip on the mandrel.
What am I doing wrong ?? Is the "doughnut" mandrel the wrong choice for brand new cases ?
I have read on Accurateshooters.com somewhere that it is "better" to use the same manufacturers Expander & Turning mandrels but I cant convince myself that the answer to this problem could be so simple
Thanks in advance for any suggestions
Ecomeat

[bruce moulds]

possibly the sinclair expander is a little undersize with that brass for the k&m turner mandrel.
keep safe,
bruce.

[Gadget]

Hi ecomeat
I alway use matching kit, the K&M expander pins are sized just right for the K&M turning tools.
I have them in .223/6mm/6.5mm/and 7mm and have had NO issues with any of them.
In fact I will load case's after neck turning without re neck sizing, I think it is about 1th nk tension.

Comment from K&M site.

A dab of Imperial Die Wax on the Pilot will ease the turning. Do not use the Pilot dry - lube is required or the brass will gall. High speed will generate too much heat and steel expands (cal. 30 pilot + .0001"/50°F). Metal must be kept cool for any precision machining. This operation is no exception

[AlanF]

Ecomeat,

I have the K&M donut cutter mandrel, but haven't seen the need to use it on new brass, only when donuts develop after several FL resizes. And when I have used the cutter, its not a particularly elegant solution. It doesn't seem to get rid of the donut unless its angled over somewhat from the alignment of the neck, and then its difficult to get a uniform finish.

I think a donut avoidance strategy is best :

1. Seat projectiles such that the entire bearing surface is shallower than the neck-shoulder junction of the case (this needs to be considered when specifying throat dimensions).
2. Neck-size no more than 2/3 of the neck length.
3. When you neck turn, make sure the neck turner cutter has a small angled edge that cuts at least 0.050" up the slope of the shoulder to a thickness about the same as you're turning the necks to.

Lastly, I think neck turning is over-rated as an accuracy tweak, for our type of shooting at least. I started doing it because of uneven neck thickness in Lapua 6.5-284 brass in about 2004. The brass has improved since then so I now have no-turn neck dimensions in my 284 Shehane chambers, and probably won't bother with it from now on.

Alan

[IanP]

Hi ecomeat, Alan has given some good advice. I haven't used the K&M and use no-neck chambers for all my calibres. Bill Shehane gave me good advice when I set myself up with the 284 Shehane and that was if you are using good brass (lapua, norma) then get a no-neck turn chamber.

The thing is with some wildcat cartridges sometimes the shoulder (thicker brass) will get used to shape the lower part of the neck and eventually donuts will form. In which case you would inside ream after they form or neck turn down into the new shoulder to prevent them from forming.

I use both Wilson and Forster inside reamers and favour the Forster these days because the Forster Original Trimmer (needed for the reamers) has a handle to turn instead of a knurled knob as used on the Wilson trimmer.

In getting back on topic with your question you dont need to inside ream new brass. Most inside reamers are made to be used with fired brass and not with the Sinclair expander as it doesn't open the neck enough. I have 223R lapua cases and needed to inside ream them after about 7 firings. My advice would be to get a K&M mandrel without the donut remover and use that. If donuts become an issue then buy yourself a top quality Forster Trimmer and reamers to suit your calibre.

Handloading for Competition (Glen Zediker) is a good book to buy if you already understand the basics of reloading.

Ian

[ecomeat]

Thanks for the input...please keep it coming.
This new 223 that Phil Jones built for me is a tight neck (.243 Match, compared to the normal 0.253) so I have to neck turn these new cases before I can use them initially, and the "doughnut cutter" mandrel is the one that came with the K & M turner kit.
Bruce, I actually just found a new K&M 22 Cal Expander Mandrel in a draw and put a micrometer on it, and it is half a thou (5/10,000) bigger than the Sinclair 22 Cal Expander Mandrel.
Gadget, I am conscious re temperature of metal, and do all possible to keep things cool. I use two partly thawed freezer gel pads, and put the Turner tool between them as I finish each case, and while I visually check it and then load up the next case, to keep the temp as low as possible. It seems to work really well .
I'll go and run another 25 cases thru the K&M expander followed by the (K&M) Turner, and will report back.
Ecomeat

[bruce moulds]

eco,
ians reamers are for proper reaming, whereas the k&m mandrel is only for removing any donut that exists at the initial neck turning time.
his reamers are best ordered to suit fired brass in your chamber, or for brass from a non bushing fls die. the best way to use them is to have a special fls die which allows the reamer to enter the neck while the case is in the die.
in the old days this was done rather than neckturning, but is presents hazards.
i suspect ians reamers are sized to only remove donut material.
what alan says is good advice re keeping the bearing surface/boattail junction above the donut area.
one way to minimize donuts is to take the neckturning cut into the thoulder/body junction of the case, but not so far as to weaken it.
while neckturning might not be advantageous, done properly it can be no disadvantage. at least in the back of your mind, you know that you have done all you can to achieve consistent neck tension, and thinner nechs take longer to work harden than thicker ones.
new processes and the learning that goes with are great fun,
keep safe,
bruce.

[ecomeat]

it wont be much of a surprise to you "old hands" to hear that the K&M Expander, followed by the K&M Turner......even though its the "doughnut remover", worked flawlesly, with barely a mark on the inside of the case necks.
That 0.0005 makes all the difference.
Another lesson to remember !
Thank you all for the good advice. I really appreciate it.
Ecomeat

[johnk]

Most of us are just not pretty faces, or whatever.

[ecomeat]

Ian,
I just ordered Zedikers book, plus some reamers and a heap of other goodies from Sinclairs.
Thanks for the advice.
Tony Berry