K and m neck turning tool

[BucksAndBulls]

I just bought a k and m neck turning tool and I can't get the power adapter to spin the cases straight they all wobble horribly. I have tried new and once fired lapua 6.5 284 cases, and new norma 7 saum cases, I tried to re position the cases in the holder every way i can and all spin 1/8 inch plus from being concentric... has anybody else had this problem? Is it something I should be worried about, should I hold off on neck turning and get a new case holder? I did turn a few of the lapua cases just to clean them up and it seems to me that it is cutting more on one side of the neck than the other... thanks,
Mike

 

[Bill Johnson]

Mike,
The first thing I would check is the drill chuck itself. Many cordless drills just aren't very good. That said, it you are sure it's the tool, K&M will make it right. My K&M tooling is just some of the best I've ever bought and they're a good bunch to do business with.

P.S. AS far as turning one side more that the other, it's very common with the majority of cases, except Lapua, for wall thickness to vary as much as .006 or so one side to the other. I set mine up so it produces a .012 neck wall. When most cases are run through it at that setting, it ends up only removing material from about 75% of the neck, so that's normal.

 

[BucksAndBulls]

Thanks Bill.... I did check it with another drill and it is the tool, I can see the wobble in the case holder its self...
Mike

 

[el matador]

Mine wobbles a bit but it doesn't bother me. I turn at a fairly slow speed and don't remove too much brass. All brass has variation in neck thickness, that's why we turn it! "Cheaper" brass like Remington, Federal or Winchester frequently varies by a few thousandths from side to side and cleaning up 75% of the circumference is the norm.

 

[Gene]

I buy a K&M neck turner for each competition rifle I shoot. That way, never need to re-set it. When I began to turn necks, I showed it to my well known gunsmith and he said a little wobble is OK. You need to check the thickness on at least 3 sides with a tube mic to determine whether the necks are concentric.

 

[Canadian Bushman]

Mine wobbled horribly, so i moved to holding the cases in a 5c collet in my mill.

However the mandrel pretty much forces the neck into cutting a concentric thickness. I could not discern much difference between the end result of turning in the holder or the collet.

Your assembled cartridge runout may be a little worse with the holder but will iron itself out after the first firing. Virgin brass always runs out horribly anyways.

 

[RandyinVa]

To Canadian bushman, the solution is not to put either side in a fixed position (you mill). You want the cutter in one hand and the case in the other, Your hands will move if an imbalance with the end result MUCH better than one side fixed. It would be a shame to use premium brass and go backwards trying to true the necks (and shoulders).

 

[Canadian Bushman]

To Canadian bushman, the solution is not to put either side in a fixed position (you mill). You want the cutter in one hand and the case in the other, Your hands will move if an imbalance with the end result MUCH better than one side fixed. It would be a shame to use premium brass and go backwards trying to true the necks (and shoulders).

I disagree.
The k&m shell holder is a rigid mount that runs very crooked. No amount of free movement will allow you to apply force in a manner which is true to the longitudinal axis of the case. Over time your muscles fatigue and what you think is compensating for bad alignment begins exaggerating it. The solution is to mount the case in a manner that allows it to run more concentrically with the longitudinal axis. Which is how the sinclair tool, rcbs tool, and the collet of my mill all do. 90 percent of the time the body of a case will be more parallel to the walls of the neck than the head will be perpendicular to it. The body also offers much more surface area for holding power than the area of the head.

In my mill, chucking on the od of the body, my cases usually run within .001-.005 and are aligned over the centerline of the axis of the mandrel within .001. Since it is rigid it never moves each one of my cases will be held the same. It is also a controlled rpm so the cutter is being introduced to the brass at the same speed everytime. I highly doubt anyone can reproduce more consistent results by hand.

Last batch i neck turned the entire lot of 300 measured within .0005" variation of thickness and many were within .0001-.0002". After initial fire forming this brass also produces very good run out and extremely consitent neck tension. I have no doubts in my methods.

 

[Mikecr]

I use a Neil Jones case lathe and Sinclair NT4000 sys. The lathe shaft wobbles all over heck, but it doesn't matter provided the turner is hand held.
If I were buying equipment today, I'd go to PMA for the lathe(Sinclair holder):
PMA Tool
Provided I have the correct turning mandrel fit, good lube, and manage turner heat, I can turn very good, even with a bit of case wobble originating from casehead.

At one point early on I used the K&M system like OP, and was not impressed with it as a whole. This was hard to accept because I really like K&M products. But going to Sinclair and comparing all features side by side on the bench put the choice in favor of Sinclair system(for several reasons).