Neck turning, sizing die, and neck tension?

[ronstone09]

I have been researching a bunch and from what I gathered I could fl size my brass then neck turn. After that seat a bullet into the case. Take a micrometer a measure outside diameter of the neck then subtract 2 thousandths. That would give me a bushing size. Is that correct?

Correct

 

[misterc01]

I measure the neck thickness with an RCBS Vernier Ball Micrometer.If the measurements the same at three points around the neck I leave as is. IF not. I clean it up to get to even measurement around the neck. Then use the correct busing and size for .002 thousandths neck tension. Neck turning is a one-time process. same for primer pocket uniforming, deburr, etc. New brass is easiest, fired brass I FL resize to start with a standard case.

 

[Mikecr]

how do you decide between the choice of a bushing die or a mandrel? currently I have a basic 3 die set from Redding. 280 AI. I am wanting to get a more consistent setup.

You're hijacking the thread with this. Should start a new thread.

 

[Alibiiv]

I have been researching a bunch and from what I gathered I could fl size my brass then neck turn. After that seat a bullet into the case. Take a micrometer a measure outside diameter of the neck then subtract 2 thousandths. That would give me a bushing size. Is that correct?

I have been fire forming Nosler brass for my .270 Ackley Improved. I am waiting for a set of custom dies to be made; yet, I want to shoot the rifle to break the barrel in and have some brass to work with. What I have been doing is just neck sizing the brass using a .270WSM resizing die, the regular .270 Winchester die will not work due to the 40 degree shoulder. While doing this procedure I leave the neck expander ball out of the die. After the neck sizing I run the neck sized brass up into a Sinclair .275 (?) mandrel die. From this point I am turning the necks. During the neck turning process I noticed that about 1/2 way down the neck the brass was thicker as I turned closer to the neck/shoulder datum line. I have read that there are two options when one is turning necks on brass. One option is to do what I am doing and pushing out the brass from the inside to the outside. The second option is to use the regular neck expander ball, full length resize pushing the donut into the inside of the case and reaming the inside of the neck to remove the donut. The process that I use is pushing the excessive brass, donut, out to the neck that gets removed when I turn the outside of the necks. Hope this makes sense to you?? I'd like you to know that I was happy to see your post, I too am new at precision reloading. I haven't gotten to the bushing dies yet. Benn at Hornady told me that once I get my dies I will not need a bushing die.

 

[Wedgy]

I have noticed a great deal of once fired brass has run out as bad as 3 thousands. I was hoping to make it more concentric in hopes of improving accuracy, but if you think I will not achieve that then it's not worth spending time and money on. Thanks for the info.

Just check to see if what you are calling runout is not case neck thickness variation;
to measure case thickness you need the vernier ball micrometer as previously stated(see picture) and to measure case runout you need a concentricity gauge

 

[MOOSE39465]

I measure the neck thickness with an RCBS Vernier Ball Micrometer.If the measurements the same at three points around the neck I leave as is. IF not. I clean it up to get to even measurement around the neck. Then use the correct busing and size for .002 thousandths neck tension. Neck turning is a one-time process. same for primer pocket uniforming, deburr, etc. New brass is easiest, fired brass I FL resize to start with a standard case.

I think I'm gonna try it.

 

[MOOSE39465]

I have been fire forming Nosler brass for my .270 Ackley Improved. I am waiting for a set of custom dies to be made; yet, I want to shoot the rifle to break the barrel in and have some brass to work with. What I have been doing is just neck sizing the brass using a .270WSM resizing die, the regular .270 Winchester die will not work due to the 40 degree shoulder. While doing this procedure I leave the neck expander ball out of the die. After the neck sizing I run the neck sized brass up into a Sinclair .275 (?) mandrel die. From this point I am turning the necks. During the neck turning process I noticed that about 1/2 way down the neck the brass was thicker as I turned closer to the neck/shoulder datum line. I have read that there are two options when one is turning necks on brass. One option is to do what I am doing and pushing out the brass from the inside to the outside. The second option is to use the regular neck expander ball, full length resize pushing the donut into the inside of the case and reaming the inside of the neck to remove the donut. The process that I use is pushing the excessive brass, donut, out to the neck that gets removed when I turn the outside of the necks. Hope this makes sense to you?? I'd like you to know that I was happy to see your post, I too am new at precision reloading. I haven't gotten to the bushing dies yet. Benn at Hornady told me that once I get my dies I will not need a bushing die.

I was planning on fl sizing my brass and bump the shoulder back 2 thousandths. Then neck turn my brass. I was hoping it could be that easy. From the sound of things it more complex then that.

 

[MOOSE39465]

Just check to see if what you are calling runout is not case neck thickness variation;
to measure case thickness you need the vernier ball micrometer as previously stated(see picture) and to measure case runout you need a concentricity gaugeView attachment 143104 View attachment 143105

Wedge it is neck thickness variation. I have that same micrometer on order now. I will buy the gauge neck. Thanks.

 

[Wedgy]

Wedge it is neck thickness variation. I have that same micrometer on order now. I will buy the gauge neck. Thanks.

Grinding the outer radius of the stem down a little will let you get closer to the shoulder where the doughnut would form.

 

[MOOSE39465]

Grinding the out radius of the stem down a little will let you get closer to the shoulder where the doughnut would form.View attachment 143123

Good to know thanks. That's a clever idea.

 

[ThrdKllr]

The cutter on the neck turn tool needs to have the same angle or slightly less than the angle of the shoulder on your brass. When turning just kiss the shoulder (a sixteenth or less). This prevents the dreaded donuts. Full length size, run it over an expander mandrel .001 larger than your turning mandrel and lube the necks. It works better to cut in small increments and recut to get to the dimensions you want.