Neck turning

[Schnyd112]

I am new to neck turning. I use a k&m tool and a cordless screwdriver, about 300 rpm. I am getting very rough necks when I turn the brass. I have tried going slow, have tried hand turning, have tried steel wool, tried putting the neck turner in a vice rather than holding both parts and I still have ridges on the necks that catch a fingernail. I know this is no good.

Any suggestions? Tricks of the trade? I am turning lapua brass (.260) from .0155+\- .005 to .014-.0145. I would like them to be .0145. Using k&m expanding iron, cut to length, imperial wax on the neck turning mandrel and inside the case neck. I am still just trying to get clean cuts before I get real picky about it the dimensions.

My rifle should be complete by the end of February and I want to have brass prepped and ready to go. My chamber neck is cut to .296 and I would like to have loaded necks at .293.

 

[Okanogan]

tag. I've got plenty to learn about neck turning.

Tried it last year with K&M kit and ended up with smooth cuts but obvious variations that made run out worse. My only lesson thus far would be to start learning by practicing on cheaper brass. (I'm okay with ruining my WW brass because it meant I didn't ruin my Norma brass)

 

[toliver]

Are you you sure the orientation of the cutter is correct?

 

[toliver]

http://kmshooting.com/kmshooting/media/pdf/neck-turner-orientation.pdf

LINK to orientation diagrams

 

[Schnyd112]

Yes, the cutter is properly placed, as far as I can tell it will only go together one way. As instructed I turn the brass as if screwing in a screw. I don't have the feel yet, but want to make sure the practice I am using isn't something way different. I know it involves some finesse so maybe I just need to keep practicing. I do have to win brass that I will practice on so I don't keep making $1 mistakes.

And any tips you can provide will be great.

 

[flashhole]

I have the K&M system and use it with excellent results. My cutting speed is the fastest I can get on my drill press. I run the cutter up and down the neck a couple of time to be sure there are no irregularities in the cut.

 

[Bart B]

I don't think .0005" spread in neck wall thickness will matter enough to make a difference in accuracy. Considering the fact that with a .002" spread in neck wall thickness, if the case neck is well centered on the case shoulder, the hole in it for the bullet to fit will be only .001" off center in the chamber neck when the round's fired.

Doesn't matter if there's .0015" clearance around the case neck to the chamber neck (with your .296" chamber neck and .293" case neck) or .003" clearance (with a .299" chamber neck); bullets will be equally centered in the chamber because it's the case shoulder centering in the chamber shoulder that aligns the bullet to the bore. But less clearance means longer brass life.

 

[Schnyd112]

I realize that .0005 difference (+\-.00025) from piece to piece isn't much. My problem is getting them from loaded neck diameter of .296 (unturned) to .293 (turned) so I can chamber the round. .296 is too tight to chamber, which I knew would be the case. I want to take just enough off of the brass to get things to fit and figured .293 is a good starting point. It's a long range competition rifle so I want to do everything I can to wring accuracy (and consistency) out of it.

I am more or less just trying see if there are any tricks to turning necks or if I really am just not very good at it.

 

[woods]

I tried a K & M that belonged to a friend before buying and we both agreed that the blade was too narrow and did cause a rough neck

So I went with the Forster hand turner which has a much wider blade and makes for smooth necks

Costs a lot less too

 

[Schnyd112]

Yeah that looks real nice. I read some people having trouble with the forester and either not being able to cut all the way down the neck or cutting too far into the shoulder with the wider blade. Does not look like you had any problems.

 

[Schnyd112]

This is what mine look like. This is before the steel wool. All that really does is cleans up the bottom of the cut. It doesn't seem to smooth hem out much

 

[dok7mm]

Thanks for posting the pictures. I turn necks with K&M tools for a number of tight and/or minimal neck rifles, including .296 nk 6.5s. I had some cases similar to yours, when I first started, so I feel your pain. The most likely causes are #1- advancing case to quickly - go slowly, #2 brass spring back - lube and expand necks just prior to turning, I expand 1 case and turn immediately, #3 inconsistent lube - I use Imperial on Qtip to lube neck prior to expanding, relube prior to turning and lube mandrel for each case, #4 - Turner temp gets to warm and changes fit of case neck to mandrel - I use the heat sink holder to do about 10 cases and then set it on a cold pack and switch to another setup for 10 cases. I am assuming you are FL sizing all your brass consistently, then trimming to a very consistent length and chamfering prior to turning. I think the heat sink grip really helps to give a good grip and stabilizes the turner. You want everything handheld, as this floats when turning and lets the mandrel keep case neck straight. Just slow down, and concentrate on making one perfect case at a time. Always check that case stop feature is set to just turn shoulder/neck junction a short amount. Lastly, try taking off 75-80% in first pass (all cases) then take the remainder in a clean-up/ final pass. This is not something you will perfect at the start, but in time, it will pay off for you in lower ES/SD, if you use the same precision in your loading. One last tip, turn the tool over, so you can see the cutting edge of the cutter, as it is where you will see exactly how deep your cut is. You should see fine chips or a Very Fine thread. IF more, you are taking too deep a cut.

 

[LoneTraveler]

There is several variables to get smooth cuts on metal. The angle of relief and chip angle on the tool affect finish. The inches of cut per minute effect finish. Circumfrence of shaft X RPM = Inches of Cut per Minute.

Use a lubricant that will stand the speed to keep the case from gaulding, heating and expand the neck a couple thousandths which may allow the case to chatter on the mandrel and cause problems. Try using a turning tool that runs faster than 300 rpm may give you a better finish. You will just have to search to find the combination to get a smooth finish. Good Luck in a solution.

 

[newmexkid]

My problems were cutting to deep into the shoulder. Using patience I figured that one out. I like a slow speed drill and work the brass into the cutter as slowly as I can. Makes for a perfectly smooth cut that never requires steel wool to clean up. Turning necks, for me, is very enjoyable, (Hey! I'm retired) and I always go slow in feeding the brass into the cutter. Honestly, I have never seen brass look like yours after turning. Too fast with the feed rate?