Neck turning angles

[Ledd Slinger]

That one is done with a 40° while the virgin case is 30°… Straight ackley headspaced off the neck shoulder junction. After 14 firings, those cases have ZERO thickening/taper, BUT they have had the crap sized out of them every loading. I just recently took a sample of those original BRA cases and inspected for brass flow, and there is NONE....I was simply amazed to be honest given the abuse they've received. That barrel is semi retired so the brass will move on to "abusive duties". My reamer grinder got my new reamer a bit shorter, but still plenty clear of any problem areas. Really liking the longer necked BRA vs the "washed up" dasher.

Tom

With no measurable brass flow off the shoulder are you saying that the case trim length remained consistent as well? I would imagine there was some neck stretching.

 

[Ledd Slinger]

Just think about it, how is cutting into the shoulder going to maintain its integrity or make the case stronger? It can't it, can only weaken the case.

If there is any excess material/brass at the shoulder neck junction the pressure and heat is going to blow it forward the next time you fire that piece of brass. Its just that simple. YMMV.

Joe

Well then don't cut into your shoulders if it makes you feel better. Nobody is saying "this is the way it MUST be done"

Its not like this is a new practice. Brass has been turned this way for many years now. When one of my hundreds of cases has a failure at the neck shoulder junction, I'll be sure to let you know. Until then you can continue to assume Hornady knows what they're talking about.

 

[Ledd Slinger]

Not much, maybe .004 in 14 loadings. What I did was set up to full length size the necks, expand and 're turn them. After 6 random samples that just evenly cleaned the dirt off all the way to the junction I decided to stop and measure. I randomly measured some from each box, and could find none that hinted at a doughnut/thickening/taper.


Tom

Wow! That's amazing. Did you also anneal after every firing?

 

[Ledd Slinger]

I only anneal when I want to shoot bigger groups!

Tom

Now I'm confused ...Lol.

 

[Alex Wheeler]

The cutter is so important with neck turning. I like a couple degrees shy of the shoulder angle and I dont like a very sharp edge. Once the angle and edge are right holding .0001" is possible. Whether you believe that or not.

 

[Ledd Slinger]

All general statements are wrong some time. I'm not saying that Hornady is some kind of an authority on precision reloading, I don't think they are. I do not use their bullets or brass, but I do use some of their tools.

I have turned thousands of 308 cases into the shoulder and none have failed me. But I have stopped doing that because IMO the risk of digging a thou too much into the shoulder is not worth the benefit to me. Now that I'm running a 260AI and a 7SAUM at higher pressures I don't want to chance it. Those case have sharper shoulder angles and brass does not flow forward to the necks like a 308. I have SAUM brass on the 6th firing and the necks haven't gotten thicker yet. And until recently I was using 195 grains bullets going at 2980 fps. Now I've switched to the 180 grain going over 3,000 fps. QL tells me that's over 62,000 chamber pressure. I've only trimmed that brass once.

IMO both practices can work, but it depends on the caliber, powder, pressures, brass you're running, whether you anneal or not, etc.... Like everything else its multi factorial. Ultimately, you make the decision, you bear the consequences.

Good luck,

Joe

That's fine. As long as it works for you and you're comfortable with the way you prep brass. Just don't try to spout Hornady video statements that disagree with a known safe practice for turning necks. If you're not comfortable with turning onto the shoulder then dont do it. Every part of reloading is very dangerous if you don't know how to do each step correctly. We are basically making high explosives then igniting them right in front of our face!

I'd bet most guys are running 62K or even more presure in their 6BR brass.

 

[Alex Wheeler]

What kind of pressure is a 6BRA at when pushing a 103 at 3100 in 28" using H4895?

 

[21shooter]

Alex, That's exactly the way I GRIND the carbide cutters for the 21st century shooting neck turning tools.
(Always have) John

 

[Ledd Slinger]

Alex, That's exactly the way I GRIND the carbide cutters for the 21st century shooting neck turning tools.
(Always have) John

I figured you would know to do it that way John Thanks for the clarification on that.

 

[Alex Wheeler]

Alex, That's exactly the way I GRIND the carbide cutters for the 21st century shooting neck turning tools.
(Always have) John

John, never used one of yours. Mine are hss (old sinclair) and once I grind the angles I want I will stone the edge a little to dull it slightly. The increased cutting pressure seems to force the neck against the mandrel and hold a better tolerance.

 

[gunsandgunsmithing]

John, never used one of yours. Mine are hss (old sinclair) and once I grind the angles I want I will stone the edge a little to dull it slightly. The increased cutting pressure seems to force the neck against the mandrel and hold a better tolerance.

I don't know how a dulled cutter would help anything but I do prefer a tight mandrel vs one with any clearance. I was just discussing this with a fellow shooter within the last day or so.

I make my own mandrels and like to have about .0005-.0007 interference fit. I just lube the case and mandrel a tad and use a fairly slow rpm going on, then speed it up a bit coming off. The finish is good and my necks are always +/-.0001. With clearance, I don't feel like imperfections will be pushed and held the the outside, against the cutter. It also helps a lot to use a min turn neck or do them in two passes. I much prefer NOT having to do a second pass, as I kinda hate case prep.
I feel like a good sharp cutter, along with a light cut, minimizes cutter and mandrel deflection. In turn, this yields a very consistent finished product.

I'm not saying your or other methods don't work, just that this makes sense to me, being from the tool and die industry, and gives ME good results.

edit...When I turn on the lathe, I make the mandrel in a single setup, taper it gradually and use the tail stock to expand the neck and hold the case for cutting. Then pull it off of the mandrel using the tail stock. This works very well too.

I never re-use that mandrel and I don't take it out of the chuck until I've turned all the necks, so the setup remains the same all the way.

 

[Alex Wheeler]

Its just edge prep. An edge with a higher cutting force is going to push the neck into the madrel. Its very forgiving to use. I didnt say dull, just not razor sharp

 

[Ledd Slinger]

Johns expander and turning mandrels are extremely precise. There is absolutely NO play between the case neck and turning mandrel after exapansion. Yet the case goes on the mandrel pretty easily. I dont even use lube for short neck cases. But that might be because I use the nitrided turning mandrels.

The cutters go through the brass like a hot knife through butter. I can't measure small enough with my concentricity gauge to detect inconsistencies on any piece of brass turned. I don't even check em after initial setup anymore. I can turn a neck on a case, then take the same case, size it and expand it, put it back on the turner and the cutter is so precise it will NOT touch the neck at any spot again.

 

[gunsandgunsmithing]

Its just edge prep. An edge with a higher cutting force is going to push the neck into the madrel. Its very forgiving to use. I didnt say dull, just not razor sharp

It helps with surface finish in some cases, too.

Johns expander and turning mandrels are extremely precise. There is absolutely NO play between the case neck and turning mandrel after exapansion. Yet the case goes on the mandrel pretty easily. I dont even use lube for short neck cases. The precision is amazing.

The cutters go through the brass like a hot knife through butter. I can't measure small enough with my concentricity gauge to detect inconsistencies on any piece of brass turned. I don't even check em after initial setup anymore. I can turn a neck on a case, then take the same case, size it and expand it, put it back on the turner and the cutter is so precise it will NOT touch the neck at any spot again.

Consistency is where it's at, IMO. Sounds like it's working for you.

 

[Ledd Slinger]

Fresh annealing on the cases is the key to making the precision of a good cutter like the 21st century work properly. The difference between the expander and turning mandrel is so small and precise, work hardened or improperly annealed brass will spring back too far after expansion and make turning difficult without constant application of lube. I personally don't like lube in my necks.

I'll even anneal brand new brass before turning just to make sure the annealing is done correctly and consistently on each case

 

[fyrewall]

My vote is for Toby Bradshaw (1st reply). I think the band on the shoulder near the neck is the result of the brass being bermed up as a result of having the shoulder set back and the neck lengthened (plastic deformation?) that caused a elevated area and the angled cutter blade, matching the shoulder angle, neatly shaved off the elevated area without touching the remaining shoulder that was not disturbed. The new part of the neck that was part of the shoulder was also turned down by the main edge of the blade. The junction of neck and shoulder will be made very uniform by the intersection of the 2 cutting edges of the neck turner.

My plans are to get 3 spare cutter blades for my RCBS neck turner and grind them to fit 3 of my wildcats that I neck down.

As for the annealing stuff, I prefer my necks the have some spring back after they are pulled over an expander plug because I think they grip bullets better. In the event I size without an expander neck size diameter is controlled by a bushing. I also or use of Forster dies having honed out necks.

************* edit

Looking at my simple low budget RCBS neck turning tool I see a tool steel cutting blade that engages the brass neck, offset to 1:00 o'clock, at a 90 degree angle (down slope from 12:00 o'clock); the other side, the beveled edge, is facing away from the direction of travel. Periodic blade re-forming needed and this is done with a diamond stone. Upon engaging the cutter with the brass neck there is no clearance between the mandrel and inner brass neck; cutting is independent of force but having a good straight edge with a 75 - 80 degree bevel on the cutter blade assures a nice shiny smooth neck. In the event lots of neck brass is needed to be turned off, like turning necks that were once .30 to 6.5mm brass is turned off in 2 or more steps. The brass is chucked up in my DeWalt cordless and spun at low rpm's.

On the head space. It sure looks like the brass was bermed up on the shoulder. This would happen when the shoulder was pushed back. The brass was deformed beyond recovery making it plastic (plastic deformation??). Some brass might have migrated back into the neck area, some brass was squashed and flowed into the shoulder. Headspace might be affected at least on the first firing, turning off the berm with an angled cutter would make for more consistency.

As usual, I found threads like this a valuable read enabling me to make more good ammo faster.

 

[BoydAllen]

I believe that Ken Markel, founder of K&M believed that for brass a negative rake angle was called for and ground his cutters that way. I assume that the new owner still does. This may be for the same reason that Alex Wheeler mentioned he likes his cutters slightly dull.

Years ago when I was turning necks for a tight neck .222 Remington, with what must have been a dull K&M cutter I noticed that my turned cases had grown several thousandths from that process. It seemed that in addition to turning the necks I was also doing some pressure forming. Since I did not have the tools to properly sharpen the cutter I ordered a new one and the problem went away. I have not checked for that in many years. I will try to remember to do that sometime soon.

I have a bag of free "range brass" that I use to set up turners, to spare my expensive stuff. It is .222 that can be cleaned up, sized and expanded for a .22 caliber setup or expanded for 6mm.

One of the reasons that I like to let my tool and case have the freedom to move as I turn is that in the past I had issues with the plain mandrels that Sinclair furnished with their turners. They tended to transfer brass to the turning mandrel from the inside of the neck below where the cutting was taking place. Freeing up the fit helped but without that interference I became dependent on the cutter to keep the neck pinned to the mandrel if I wanted the best tolerances. With some practice I could turn very respectable necks with a relatively loose fit. I know that some will have an absolute hissy fit at the idea but it can be done. IMO if things are heating up much during turning something about the process needs to be changed. I also do the fast feed to the shoulder slow back to the mouth thing so that I leave a good amount of material to cut on the way back to keep the neck pinned. I also put a little sideways pressure away from the cutter, into the mandrel as I hold the tool and cordless drill.

Not that I can prove that it shows up on targets, but in my experience the straightest fire formed 6PPC cases are not made by expanding up .220 Russian cases with a mandrel, but by first expanding to .22 caliber, turning to .010 (for a .262 neck chamber) and either fire forming without a bullet using pistol powder, or by firing a .22 caliber bullet down a 6PPC fire forming barrel (with suitable attention to having a suitable backstop) using a case full of any powder that has a burn rate close to 133. By turning at .22 the neck ends up the right thickness so that a little mandrel expanding at 6mm is required, but not enough so that necks are cocked by the axial pressure on the case. The reason that I got into this is that I wanted the cut on my cases' shoulders to be even all the way around and if the necks are cocked relative to the case body when you turn the cut will start on one side before the other, and be uneven. It has been my observation that in order to straighten a piece of metal that it has to be bent slightly past straight so that I will spring back to where you want it. With a case in a chamber there is no way to do this, so keeping things as straight as possible seems to be the best approach. This may all seem a little strange to those that only turn at the original calibers that cases come in, but when you are necking up things are different.

 

[Brians356]

Not that I can prove that it shows up on targets, but in my experience the straightest fire formed 6PPC cases are not made by expanding up .220 Russian cases with a mandrel, but by first expanding to .22 caliber ...

On first reading that seems contradictory. Then I figured by "expand" you must mean expand either raw 220 Russian cases, or FL sized cases, simply to fit the turning mandrel. The payoff in staying at 22-cal is very little expansion is required, and neck cock is avoided?

... or by firing a .22 caliber bullet down a 6PPC fire forming barrel (with suitable attention to having a suitable backstop) using a case full of any powder that has a burn rate close to 133.

Wow, I'd never considered or heard of that approach, using an undersize bullet. Was that your personal epiphany? I can surmise, but what do you consider the benefit of the 22-cal bullet, rather than "bulletless", with or w/o filler?
-

 

[fyrewall]

FYI, I added an edit to my last post.

 

[BoydAllen]

On first reading that seems contradictory. Then I figured by "expand" you must mean expand either raw 220 Russian cases, or FL sized cases, simply to fit the turning mandrel. The payoff in staying at 22-cal is very little expansion is required, and neck cock is avoided?



Wow, I'd never considered or heard of that approach, using an undersize bullet. Was that your personal epiphany? I can surmise, but what do you consider the benefit of the 22-cal bullet, rather than "bulletless", with or w/o filler?
-

I got the idea of using the .22 bullet from something that James Mock wrote. The additional step of turning @ .22 is my innovation, based on my experience and experiments trying to expand necks without making them more crooked. As far as comparing the .22 bullet method with doing the same thing without a bullet with Bullseye, it is probably a toss up except for someone who does not have a worn out barrel to use for fire forming. I am not all that excited about firing a lot of high nitro content powder in a good barrel. I have fired a few of the .22 bullet loads in one and checked for unusual copper afterwords and found none. I was concerned that the bullet might be rattling down the barrel tearing off chunks of jacket as it went, but apparently that is not what happens. I tend to enjoy trying new things as long as I do not think that they are unsafe.

Another thing that I have that I think is worthwhile is a one piece 6PPC die that has a .258 neck ID. It comes in handy when I want to turn necks thinner or return them, because, unlike bushing dies, it sizes all the way to the shoulder. It is a stock Hornady die.