Neck turning results - 223

[Toprudder]

I thought I would take a stab at neck turning, to see if there would be any significant improvements. I purchased the 21st century tool, and I went whole hog and got the carbide cutter and nitride coated mandrel. I also got the matching neck sizing mandrel and die to complete the set. (I have been very pleased with their products!).

My first bottleneck rifle loading was with 223, and that is where I have done the vast majority of my learning and experimentation. So, that is where I thought I would start with learning to neck turn. If anyone is wondering 'why waste the time on 223', it is because it is one of the less expensive rounds to experiment with, and if I waste some brass - so what. I will be able to transfer anything I learn now over to a more worthy cartridge later.

For this experiment, I matched the brass by weight (I know volume would be better) using twice fired LC. I also annealed all the brass. The sequence was as follows:

1) Decapped.
2) Wet tumbled 10 minutes (no pins).
3) Salt bath annealed.
4) Washed again (no pins) to remove any salt residue.
5) Neck sized with Lee collet neck sizer. (so neck would fit the turning mandrel).
6) Turned necks. I had the wall thickness set to ~ 0.011".
7) Lubed, full length sized, without expander
8) Expanded using 21st Century mandrel and die.
9) Wet tumbled, with pins, 1 hour.
10) Trim, chamfer and debur.
11) Matched by weight.
12) Loaded. No crimp.

I realize that it might be best to turn the necks AFTER full length sizing, trimming, etc., but my intent was to make a final product that would have the bullet completely concentric to the case body as possible, and I thought the best way to do that was to full length size AFTER the necks were turned and the neck walls were uniform. I welcome comments on this.

I also loaded an identical set, but left out steps 5 and 6. This would be the control group. Both groups were loaded at the same time to maintain consistency.

Loads were with 8208XBR powder, 22.7, 22.9, 23.1, and 23.3gn. Previously, 23.1 was my accuracy load. Hornady 75 BTHP Match.

Non-turned necks
22.7gn, 2661 fps, SD=13.9, ES=26.24.
22.9gn, 2689 fps, SD=16.0, ES=38.2.
23.1gn, 2712 fps, SD=8.4, ES=21.22.
23.3gn, 2754 fps, SD=15.1, ES=35.3.

Neck turned:
22.7gn, 2678 fps, SD=6.5, ES=18.4.
22.9gn, 2700 fps, SD=7.8, ES=19.8.
23.1gn, 2733 fps, SD=9.5, ES=23.4.
23.3gn, 2749 fps, SD=7.1, ES=18.3.

Interesting to note the consistency across the charge range with the neck-turned loads. The only one that was not better was the 23.1gn load, and the difference there was not statistically significant. I can only assume that the more consistent velocities were due to more consistent neck tension.

Shot from my 20" AR, all of the groups were 1.0" - 1.4", with the groups showing some horizontal spread that I would associate with the 10-15mph crosswind that was present, so I can't really say that any one group was any better than the others. The 23.3gn loads both showed the least amount of vertical spread, though, at about 0.5". With the turned brass showing less extreme spread, this could only translate to more accuracy at farther distances.

This was an eye opener for me. Prepping rifle brass is one of the least enjoyable parts of reloading for me, but seeing the benefits when proper attention is given during the process, it makes it a little more tolerable.

Comments welcome and encouraged.

 

[Blue68f100]

Neck turning is part of my brass prep for my match quality loads. As you found out it's not hard but time consuming to do, but only needs to be done once. I'm using the Redding Type S Bushing dies on most all of my match grade ammo. This way I do not need to run the expander and have the chance of it pulling the necks of alignment. The lower SD will show there dominance as you start shooting long distances >300 yrds.

 

[Toprudder]

Neck turning is part of my brass prep for my match quality loads. As you found out it's not hard but time consuming to do, but only needs to be done once. I'm using the Redding Type S Bushing dies on most all of my match grade ammo. This way I do not need to run the expander and have the chance of it pulling the necks of alignment. The lower SD will show there dominance as you start shooting long distances >300 yrds.

Funny you mentioned the Redding bushing die - I already have one on order! I have just one bushing on the way with it, though. Based on how that works, I will probably order another if I need to tweak it for any reason.

 

[Bfh_auto]

I thought I would take a stab at neck turning, to see if there would be any significant improvements. I purchased the 21st century tool, and I went whole hog and got the carbide cutter and nitride coated mandrel. I also got the matching neck sizing mandrel and die to complete the set. (I have been very pleased with their products!).

My first bottleneck rifle loading was with 223, and that is where I have done the vast majority of my learning and experimentation. So, that is where I thought I would start with learning to neck turn. If anyone is wondering 'why waste the time on 223', it is because it is one of the less expensive rounds to experiment with, and if I waste some brass - so what. I will be able to transfer anything I learn now over to a more worthy cartridge later.

For this experiment, I matched the brass by weight (I know volume would be better) using twice fired LC. I also annealed all the brass. The sequence was as follows:

1) Decapped.
2) Wet tumbled 10 minutes (no pins).
3) Salt bath annealed.
4) Washed again (no pins) to remove any salt residue.
5) Neck sized with Lee collet neck sizer. (so neck would fit the turning mandrel).
6) Turned necks. I had the wall thickness set to ~ 0.011".
7) Lubed, full length sized, without expander
8) Expanded using 21st Century mandrel and die.
9) Wet tumbled, with pins, 1 hour.
10) Trim, chamfer and debur.
11) Matched by weight.
12) Loaded. No crimp.

I realize that it might be best to turn the necks AFTER full length sizing, trimming, etc., but my intent was to make a final product that would have the bullet completely concentric to the case body as possible, and I thought the best way to do that was to full length size AFTER the necks were turned and the neck walls were uniform. I welcome comments on this.

I also loaded an identical set, but left out steps 5 and 6. This would be the control group. Both groups were loaded at the same time to maintain consistency.

Loads were with 8208XBR powder, 22.7, 22.9, 23.1, and 23.3gn. Previously, 23.1 was my accuracy load. Hornady 75 BTHP Match.

Non-turned necks
22.7gn, 2661 fps, SD=13.9, ES=26.24.
22.9gn, 2689 fps, SD=16.0, ES=38.2.
23.1gn, 2712 fps, SD=8.4, ES=21.22.
23.3gn, 2754 fps, SD=15.1, ES=35.3.

Neck turned:
22.7gn, 2678 fps, SD=6.5, ES=18.4.
22.9gn, 2700 fps, SD=7.8, ES=19.8.
23.1gn, 2733 fps, SD=9.5, ES=23.4.
23.3gn, 2749 fps, SD=7.1, ES=18.3.

Interesting to note the consistency across the charge range with the neck-turned loads. The only one that was not better was the 23.1gn load, and the difference there was not statistically significant. I can only assume that the more consistent velocities were due to more consistent neck tension.

Shot from my 20" AR, all of the groups were 1.0" - 1.4", with the groups showing some horizontal spread that I would associate with the 10-15mph crosswind that was present, so I can't really say that any one group was any better than the others. The 23.3gn loads both showed the least amount of vertical spread, though, at about 0.5". With the turned brass showing less extreme spread, this could only translate to more accuracy at farther distances.

This was an eye opener for me. Prepping rifle brass is one of the least enjoyable parts of reloading for me, but seeing the benefits when proper attention is given during the process, it makes it a little more tolerable.

Comments welcome and encouraged.

I noticed similar results when I was working on 260 Rem loads. I found that annealing and turning 308 down to fit the chamber neck made an even bigger difference than using 260 brass.

 

[cheygriz]

Every serious reloader should experiment with bench rest loading techniques at some time or another. Whether you decide it's wortwhile, or not, it's a learning experience.

I even went to hand made dies, cut with the same reamer used to cut my rifle's chamber, and an arbor press before deciding it wasn't something I wanted to do. But I learned a great deal about loading!

 

[Walkalong]

I have just one bushing on the way with it

No one ever ends up with only one.

 

[Toprudder]

Every serious reloader should experiment with bench rest loading techniques at some time or another. Whether you decide it's wortwhile, or not, it's a learning experience.

Absolutely!!

No one ever ends up with only one.

Yeah, pretty much what I figured. I also ordered the storage box they make for them - planning ahead.

 

[Blue68f100]

No one ever ends up with only one.

Ant that the truth. You normally try to do it with 3. 3 leads to 5, 5 leads to 7....

If your able to make all the brass you own in that caliber the same wall thickness you could get by. Never happens that way with me. I like experimenting.

 

[doubleh]

I'm still stuck on the need for a carbide cutter on brass. I may make it to the next step after I solve this.

 

[Toprudder]

I'm still stuck on the need for a carbide cutter on brass. I may make it to the next step after I solve this.

Steel will work on brass, but carbide holds an edge longer. At least that is the way I look at it.

 

[Blue68f100]

The HS steel will give you a cleaner cut but will not hold up as long. What seams to happen is as we trim brass using power tools, the faster we go the more heat is generated at the cutting edge. As it heats up it gets to a point where brass will start sticking to the cutting edge. This is when it will start leaving a little more flash on the edge. If you just use a damp rag with any kind of lubricant/cutting oil it cools the edge and keeps brass from sticking. Just touch the mouth of the brass to the rag/oil before you make a cut every 5-10 time. You will have to experiment on how long you can go before needing it reapplied. Carbide is very hard and is used when time is money, so you crank-up your speed. Even in production work a lot of times a cobalt or HS cutting tool is used for the final cut since it gives you a better finish. Now with hand crank trimmers the HS steel will give you a better cut since they work better at light cuts. Now if your trimming brass for the first time and your removing > 0.010" carbide is a better choice since it likes heavier cuts.

 

[Toprudder]

I have not tried the steel cutter, but I have been very happy with the carbide cutter so far. Everything I have done so far is first-time, though. But the final product almost looks polished. I am using a hand drill to turn the brass, makes quick work of it.

I'm guessing the steel cutter would be very easy to sharpen - the carbide not so much.

 

[Nature Boy]

Very interesting results on the SD and ES numbers

 

[243winxb]

I like your test. Its the only way to know for sure, do your own testing.

8) Expanded using 21st Century mandrel and die. I can only assume that the more consistent velocities were due to more consistent neck tension.

Or different neck tension? The expander should have made the ID of the neck the same? But was spring back different?

I check neck tension this way- Measure necks outside diameter before and after bullet seating. After seating, how much has the OD expanded. I have not compared turned vs unturned , so don't know the answer. The minimum bullet pull for 5.56 is 35 lbs. Bullet seating should expand the neck a minimum of .002" from my testing.

The auto loaders may move the bullet on chambering. Shorter COL from the feed ram or longer COL from the sudden stop on chambering.

There are many mysteries involved with the 223.
1. Shoulder set back from the firing pin strike. Savage Axis using a spent primer for test.
2.Head to datum shorter after firing. The hot Nato rounds will expand fully to the chamber. Starting to mid-range loads, not so much.
3. https://apps.dtic.mil/dtic/tr/fulltext/u2/a622138.pdf See page 15- Conclusions

I did a quick test with a Savage Axis, turned vs unturned. Results not clear with such a short sample. A FL die is not the best for the test.

 

[doubleh]

The HS steel will give you a cleaner cut but will not hold up as long. What seams to happen is as we trim brass using power tools, the faster we go the more heat is generated at the cutting edge. As it heats up it gets to a point where brass will start sticking to the cutting edge. This is when it will start leaving a little more flash on the edge. If you just use a damp rag with any kind of lubricant/cutting oil it cools the edge and keeps brass from sticking. Just touch the mouth of the brass to the rag/oil before you make a cut every 5-10 time. You will have to experiment on how long you can go before needing it reapplied. Carbide is very hard and is used when time is money, so you crank-up your speed. Even in production work a lot of times a cobalt or HS cutting tool is used for the final cut since it gives you a better finish. Now with hand crank trimmers the HS steel will give you a better cut since they work better at light cuts. Now if your trimming brass for the first time and your removing > 0.010" carbide is a better choice since it likes heavier cuts.

Hmm, guess I didn't realise that some would be running a neck turning operation fast enough and hard enough or to do it as production work to actually need the durability of carbide over HSS.

 

[Toprudder]

Or different neck tension? The expander should have made the ID of the neck the same? But was spring back different?

Interesting question, I had not thought of that.

I used the same expander for both the turned and non-turned brass, but will a varying neck thickness cause different spring-back? I don't know. My first thoughts are that as long as the brass hardness is the same, the spring-back should not vary with different thickness, but then I am certainly no expert on metals. I can certainly see where a varying thickness can cause varying neck tension. (I'm talking 'hold' or 'grasp' on the bullet, not how much the neck expands when the bullet it seated).

The answer to your question would be good to know, but in the end I'm not sure that knowledge would change anything in the way I would process brass.

 

[Offfhand]

No one ever ends up with only one.

AMEN to that..

 

[hdwhit]

I tried neck turning and neck reaming years ago. For the kind of shooting I do (nothing over 200 yards, most shots around 100 yards) it didn't make any difference in accuracy that I could see. I still neck ream my 5.7mm Johnson brass since the case mouths thicken during case forming, but other than that, I gave it up.

 

[Toprudder]

Neck reaming. Hmmm, something else for me to buy/try?

 

[Blue68f100]

Reaming is done after sizing if your changing the caliber of the brass. It removes the donut on the inside where the necks/shoulder/wall meets. This happens when shoulder and/or wall thickness is heavier than the neck. It's normally done before turning the necks, as it impacts the pilot. It's purpose is to smooth the inside of the neck up and uniform the necks from the inside. They say its best done with the neck supported, so it does not expand during the process. I've played with this some. A unsupported neck seams to ream a lot easier than a supported one. But this is all dependent on size and how much material your removing. Reamers are normally stepped in 0.0005", but you can special order any size you need. The problem I ran into was it took a lot of torque to ream a supported neck, heavier cut. I used a bushing to support the neck to keep it from expanding from the tool.

I need to revisit this again, to see if I can find the right combination.

 

[Toprudder]

Reaming is done after sizing if your changing the caliber of the brass. It removes the donut on the inside where the necks/shoulder/wall meets. This happens when shoulder and/or wall thickness is heavier than the neck. It's normally done before turning the necks, as it impacts the pilot. It's purpose is to smooth the inside of the neck up and uniform the necks from the inside. They say its best done with the neck supported, so it does not expand during the process. I've played with this some. A unsupported neck seams to ream a lot easier than a supported one. But this is all dependent on size and how much material your removing. Reamers are normally stepped in 0.0005", but you can special order any size you need. The problem I ran into was it took a lot of torque to ream a supported neck, heavier cut. I used a bushing to support the neck to keep it from expanding from the tool.

I need to revisit this again, to see if I can find the right combination.

Could the reaming be done while the case is in a sizing die, with the expander/decapper removed?

 

[Blue68f100]

It could but you need some means to keep it centered to true it up. Other wise it will follow the current path. I had a thread where I was playing with this. I machined a pilot to screw into top of my sizing die that used bushing. This way I could control the amount of material being removed to some degree. If you get too heave of cut the brass will try to spin in the die.

 

[Offfhand]

Mr. Blue offers a good description of reaming case necks, the importance of external support when reaming and removing the shoulder donut. However, removing the donut is precisely and quickly done by using the K&M neck turning pilots that are available with a reaming tip. (as shown in attached pic). This is what I use when finishing reformed brass, because it cuts away the donut and other interior irregularities at the same time I'm turning the neck wall to desired thickness.