Neck turning- How much per pass?

[AndyW]

What is the maximum I can remove per pass? I am using a K&M turner. Have to reduce neck diameter by .095"

 

[fullersson]

http://www.6mmbr.com/neckturningbasics.html

Everyone's opinion on this will vary. Here's an article on the subject so you can decide for yourself. Brian Brown.

 

[watercam]

I start just enough to make contact at the highest point on the neck. Then roughly .001" at a time until one reaches the 80% clean up stage. Measure that overall thickness and determine if you need to go more. I shoot no turn necks so I generally stop there unless the problem is severe - but if that is the case I may have purchased the wrong brand of brass!

 

[bozo699]

What is the maximum I can remove per pass? I am using a K&M turner. Have to reduce neck diameter by .095"

Andy,
I hope you meant .0095 not .095, what is it your working with?
Wayne.

 

[rocketron]

What is the maximum I can remove per pass? I am using a K&M turner. Have to reduce neck diameter by .095"

Andy,
I hope you meant .0095 not .095, what is it your working with?
Wayne.

if you need to reduce the neck dia. by .0095. the cut would be .00475. remember it cuts both sides of the neck.

 

[2dogs]

A tube micrometer sure is handy when trying to precision turn necks.....

 

[lightman]

I get good results by cutting .002 or less per pass.I use a battery screwdriver,which is slow enough that the cutting tool does not get hot. Lightman

 

[artbosco]

What is the maximum I can remove per pass? I am using a K&M turner. Have to reduce neck diameter by .095"

Ken Markle, the original owner of K&M Services, told me that he performed an experiment one day to see how much he could remove successfully in one pass. His top end was .015" [15/1000ths].

When I turn 6PPC brass for a .262"neck chamber, I use two dedicated K&M turners to arrive at a thickness of .0081" - .0082".

The first turner takes off the majority of the brass [about 2/3rds of it], the second one cleans it up to my desired goal.

I've known some fellas that use three turners. It's really comes down to a personal decision, that you feel comfortable with.

 

[spclark]

A tube micrometer sure is handy when trying to precision turn necks.....

Yeah, pretty much essential if you're looking for any reasonable level of accuracy.

 

[AndyW]

Sorry- Yes I meant .0095"

I ended up doing it in 3 passes, turned out great.- Note- I did not have a tubing micrometer. The expanded brass ended up with the same neck diameter as if a bullet was seated- made things a bit easier, however a tubing mic would have been a great asset.

I can also see how if one does a lot of re-forming brass owning multiple neck turners would also be an asset.

FYI- I sized 7x57 brass down to 6mm and had to turn for a .274 reamer

 

[BoydAllen]

Turn it at 7mm, leaving a half thou. to clean up after you neck down. That should radically lower your potential for developing doughnuts.

 

[Elwood]

Sorry- Yes I meant .0095"

I ended up doing it in 3 passes, turned out great.- Note- I did not have a tubing micrometer. The expanded brass ended up with the same neck diameter as if a bullet was seated- made things a bit easier, however a tubing mic would have been a great asset.

I can also see how if one does a lot of re-forming brass owning multiple neck turners would also be an asset.

FYI- I sized 7x57 brass down to 6mm and had to turn for a .274 reamer

I've been there! RWS or Norma? 6mmAI or 6mm Crusader (I think I've asked you that in a different topic)?
I used RWS 7x57 brass and had to turn 10 thou total off for a .273 finish. It took 6 passes using the K&M and many many hours. I have a 21st Century lathe on order which I'm hoping will make things easier next time.

 

[artbosco]

Sorry- Yes I meant .0095"

I ended up doing it in 3 passes, turned out great.- Note- I did not have a tubing micrometer. The expanded brass ended up with the same neck diameter as if a bullet was seated- made things a bit easier, however a tubing mic would have been a great asset.

I can also see how if one does a lot of reforming brass owning multiple neck turners would also be an asset.

FYI- I sized 7x57 brass down to 6mm and had to turn for a .274 reamer

You really don't need a tubing micrometer. A good Caliper or outside Micrometer [similar to this: http://www.all-spec.com/products/54850001.html ] is sufficient. Remember, the only dimension that really matters and the easiest to measure is the OD [outside diameter] of the case neck with a bullet seated. Jackie Schmidt taught me that a long time ago.

You simply turn, seat a bullet in a dummy round, measure the OD, then repeat till you arrive at your goal OD dimension. Heck, the majority of the guys I know, couldn't tell you what their necks are turned to, but they certainly know what the OD is with the bullet seated.

If the bullet is substituted for another brand or grain weight, you most likely will need to make a turner adjustment. There's no need to make this a complicated process or buy additional tools that you really don't need.

 

[BoydAllen]

I think that trying to substitute a dial or digital caliper for a micrometer, in this application, is not a good idea, and I doubt that our friend Jackie would suggest it. (especially since he runs a machine shop) IMO a decent 1" mic., that reads to .0001, should be in everyone's reloading kit, if he is doing anything more than turning necks for a partial cleanup. The part about measuring a loaded round to get the neck OD is pretty standard. I would add that if one is using a typical flat base benchrest bullet, that has a pressure ring at its heel, the measurement should be made over the heel of the bullet. Because of the need for the best technique for using a micrometer to measure neck thickness directly, it is always a good idea to measure the loaded neck, even if you have measured neck thickness with the proper tool. I can get along without a neck mic., but it takes longer to make adjustments without one. I try to hit my mark to .0001. I know that this is perhaps more precision than is needed, but it can be done, with a little patience.

 

[artbosco]

I think that trying to substitute a dial or digital caliper for a micrometer, in this application, is not a good idea, and I doubt that our friend Jackie would suggest it.

Boyd,

Just to be clear, Jackie never advocated the use of any specific tool, just working toward the final OD dimension. I personally use a Digital Micrometer that gives me 1/10,000ths, however, I've seen calipers used by some, who have achieved acceptable results, for something other than a tight necked chamber.

 

[BoydAllen]

Thanks for the clarification. We are in complete agreement.
Boyd

 

[AndyW]

Sorry- Yes I meant .0095"

I ended up doing it in 3 passes, turned out great.- Note- I did not have a tubing micrometer. The expanded brass ended up with the same neck diameter as if a bullet was seated- made things a bit easier, however a tubing mic would have been a great asset.

I can also see how if one does a lot of reforming brass owning multiple neck turners would also be an asset.

FYI- I sized 7x57 brass down to 6mm and had to turn for a .274 reamer

You really don't need a tubing micrometer. A good Caliper or outside Micrometer [similar to this: http://www.all-spec.com/products/54850001.html ] is sufficient. Remember, the only dimension that really matters and the easiest to measure is the OD [outside diameter] of the case neck with a bullet seated. Jackie Schmidt taught me that a long time ago.

You simply turn, seat a bullet in a dummy round, measure the OD, then repeat till you arrive at your goal OD dimension. Heck, the majority of the guys I know, couldn't tell you what their necks are turned to, but they certainly know what the OD is with the bullet seated.

If the bullet is substituted for another brand or grain weight, you most likely will need to make a turner adjustment. There's no need to make this a complicated process or buy additional tools that you really don't need.

This is how I went about it. Seated a bullet in an unturned necked down case and did the math. When I knew I was close (after the second turn) I then seated a bullet to check, and my final turn was a clean-up to get it exact. I ran all the brass sequentially so once I had the turner set for the final pass I was running all brass, no back and forth. The whole process went really smooth.

A tubing mic would be nice, and I will be investing in one but was able to do it with my calipers and seating a bullet.

*On a side note I took one piece of brass that had not been turned and ran it slooowly into the turner that was set on the final clean-up dimension- removing all .0095 in one pass. It turned out perfect. What is the downside to removing this much at once? it measures out exactly the same as the 3 pass turned brass, same visual finish as well.Harder on the cutter? I will be calling K&M and ask them this question. Sure would save a lot of time if I am not pooching the cutter.

Elwood- 7x57 RWS that I am forming to 6mmAI. All fire formed now and turned out perfect!

For those of you with 6mm's I believe it is worth the work to form from RWS. They take making consistent brass to a new level!

 

[bozo699]

Elwood- 7x57 RWS that I am forming to 6mmAI. All fire formed now and turned out perfect!

For those of you with 6mm's I believe it is worth the work to form from RWS. They take making consistent brass to a new level!

Andy,
I couldn't agree with you more on the RWS brass, I have not had the pleasure of the 7X57 brass but I have about 1000 pieces of .300wm in the RWS brass and it is every bit as consistent as Lapua in my opinion. I am sure you are aware of this but always reduce loads when starting with RWS as it is thicker and you can't load it as hot as you can some of the others.
Wayne.