K&M Neck Turner: how to

Goose25

Goose25

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I just ordered a K&M neck turning tool for my .260R, is there a website, videos, or any other source of information that can show me the "how to's" of proper neck turning? I'd like to get informed while I wait for it to show up.

Thanks,
:popCorn:
 
Without all those fancy measuring tools used to determine neck thickness, how do I determine how much brass I should be shaving off?

How often do I have to turn the necks? I'm guessing most people will do this procedure only once, but with every firing the brass is flowing, and the neck wall thickness is growing, so shouldn't this be repeated somewhere down the road?

when is the ideal time to turn the necks? on fireformed brass? when signs of the dredded donut appears? after "x" number of firings? before annealing? after annealing?
 
Takes some give and take, but look to knock off the high spots on the brass ... so no more than 50% of the neck on the majority of your brass should have trim marks on it. I tend towards about 1/3 of the neck maximum.

I only trim once on new or once fired brass. Go past the neck/shoulder junction just a bit (Zediker in Handloading for Competition is a good read). About the time you get donuts, time for new brass (or learn to anneal) in my opinion.
 
Goose25 said:
Without all those fancy measuring tools used to determine neck thickness, how do I determine how much brass I should be shaving off?

How often do I have to turn the necks? I'm guessing most people will do this procedure only once, but with every firing the brass is flowing, and the neck wall thickness is growing, so shouldn't this be repeated somewhere down the road?

when is the ideal time to turn the necks? on fireformed brass? when signs of the dredded donut appears? after "x" number of firings? before annealing? after annealing?
Click to expand...

You should get a tubing mike and a digital caliper to measure your neck turning. Anhydrous lanolin is a good lube for expanding mandrels and even carbide turning mandrels.

NormB
 
Goose25 said:
Without all those fancy measuring tools used to determine neck thickness, how do I determine how much brass I should be shaving off?
Click to expand...

Generally skim enough brass of to leave 20% of the neck untouched.

Having said that, you don't need "fancy" measuring tools like a tubing mic, since you have a K&M which is setup for a dial indicator. Get a dial indicator anywhere, zero it against the mandrel and then trim the neck.

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Goose25 said:
^I like that set-up.

where's a good place to purchase a dial indicator similar to the one above?
Click to expand...
"get a dial indicator anywhere" - they are a common item found anywhere you can get decent measuring tools.

Princess Auto, any industrial supply shop, eBay, etc.

If you care about brand, Starrett and Mitutoyo. You're looking for .001" scale with 1" travel and a 3/8" mounting stem, ideally with jewel bearings.

e.g.:
http://shop.ebay.ca/?_from=R40&_trksid=p3907.m570.l1313&_nkw=dial+indicator+Mitutoyo&_sacat=See-All-Categories

http://www.mcmaster.com/#dial-indicators/=91jfo9

http://www.sinclairintl.com/.aspx/cid=0/k=dial+indicator/t=P/ksubmit=y/Products/All/search=dial_indicator
 
In a standard chamber, I like to neck turn to clean up around 80% of the necks. This removes the high spots and makes things even enough to not matter. As long as there is enough room for the necks to expand, the final thickness isn't that big a deal.

Just don't thin so much that the necks split or can't hold the bullet.

If you are turning to fit a tight chamber, then you need to have at least 1.5 thou per side. I prefer 2 thou per side. For this, you will need to have some way of measuring the thickness properly. Tubing mic is likely the best tool for this.

I use a pair of calipers and average my readings. Crude, yes but good enough.

If you find that you have the trim the necks, odds are the necks are no longer even in thickness. The brass had to come from somewhere.

I am now skimming the necks each time I trim. With improved cases where case stretching is min, I will still give the necks a skim every 6 to 10 firings. They are much slower to thicken and almost all will be near the shoulder but if you have tight tolerances in your chamber, it will cause issues.

Jerry
 
Forget the tubing

mic and just use an outside mic.

Who cares what the thickness of the brass is. It is what the outside of a loaded round at the pressure ring measures is what matters. I have never owned a ball mic and probably never will. I may waist a Lapua case or 2 getting the measurement right but once it is set that turner is dedicated for that brass only. 2-3 thou total clearance is what you are looking for.

My chamber for my bench rifle is a .269 neck, I am turning so a loaded round is around .267 at the pressure ring.

There are more uses for an outside mic than having a ball and then a outside. Buy one and it will do the job for you.

If you click on the link at my sig line and go to centerfire discussions there is a link to a presentation by a hall of fame shooter on the techinques he used and uses to get him in the hall of fame. There is a bit for everyone on that presentation. A MUST watch if at all interested in the 6PPC.

CBY
 
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