sizing mandrel crooked

[the long shot]

30 BR

Last season I could not figure out why my turner was biting so much into the shoulder when I turned my brass down after necking it up. I used the technique of a spacer on the neck and using the neck sizer to straighten the neck before turning but the problem persisted to bug me of why it was becoming crooked. I figured out the issue. I have a one pass 6 mm to 30 cal mandrel in a K&M mandrel holder mounted on my Rock Chucker and out of curiosity I raised the ram up to the mandrel without a case in it and found the mandrel sat crooked in the K&M holder.

By not tightening down the mandrel holder I was able to let the mandrel right itself while necking up the cartridge. Has anyone else run into a similar issue? Should I send in for another K&M mandrel holder?

Additional note... Despite warnings not to from some of my competitors, I have switched over to a power drill to turn my cases "slowly" when I turn my necks. My hands like it and wow do I cut down on time.

I learned a trick though. Even though I lube up my turning mandrel with imperial wax, I use an upside down air can between turnings to cool the mandrel down to prevent heating up the cases too much.

 

[Steve Blair]

Replace your mandrel with a carbide model. It will be straight and you won't need to worry about thermal expansion.

 

[BoydAllen]

I think that he was talking about the expander die holding his expander mandrel crooked. +1 on the carbide turning mandrel.

 

[Steve Blair]

I think that he was talking about the expander die holding his expander mandrel crooked. +1 on the carbide turning mandrel.

[br]
You're right, Boyd. My error. Back to K&M for a little R&R.

 

[rogn]

I started using a drop of RCBS case lube 1/2 in the case neck and 1/2 on the carbide mandrel. Slow turn with a drill, what a difference, smooth easy and I can still use my hands to load and shoot later. QC has been better also.

 

[Ecomeat]

Longshot,
To cool the turning mandrel as you work, try using a gel "freezer brick" (the sort of thing you put in a portable cooler to help keep your drink/food cold) , and just sit the turning unit on it for the time that it can actually leave your hands while you put the completed case away, and get the next case into your drill mounted shell holder. It works as a massive heat sink, and is very effective.
If you worry about a frozen one keeping the mandrel and cutter TOO cold, then use the gel pad deeply chilled (ie overnight it in the fridge) rather than frozen, and replace when it warms up to room temp.
Rgds
Tony