Working with neck lube as a means to reduce SD/ES

[done111]

I am running some experiments over my Magnetospeed to see if lubing the neck of my brass will reduce my SD/ES. I have some dry neck imperial lube (with the loading beads) that I am trying as a first pass at the experiment. I dipped the neck in 3 times, tapped the neck on the container to shake off any excess and wiped the outside of the case to keep my hands clean when handling the load.

Has anyone had success doing this? Should I be using another means of lube? Should I worry about powder contamination? I'm using a satern funnel specific for my 6.5 creedmoor when loading my powder so hopefully that might help in powder touching the inside of the neck when going into the brass.

Don

 

[Dusty Stevens]

let us know what you find. the dry neck lube youre using works fine

 

[David Christian]

@done111 , I have done this exact testing to include measuring the seating force using a K&M Force gauge of cases with the Imperial Dry Lube against cased prepped identically without the final Imperial lube of the cases before bullet seating.

My empirical data suggests that the lube reduces surface friction and shows a lower bullet seating force, however when measured over my magneto V.3 chrono as well as actual results on a 600 yard target, there is no difference in SD or ES! I think neck hardness and a consistent interference fit are way more important. In my opinion the best way to achieve consistent interference fit is to use gauge pins to ream your case necks post sizing. I have repeated this test multiple times with the same result. Lapua SP brass, 6.5 CM, 140 Berger Hybrid bullets, H4350 powder, CCI 450 primers.

I might encourage you to read this entire artice and maybe even part 1 of their test. A good portion is related to annealing, yet part of this test addresses neck lube.

https://www.ampannealing.com/articles/42/annealing-under-the-microscope/

To quote, “As demonstrated in our Stage One report, "neck tension” is more than just interference fit. The force necessary to move a bullet in a case neck depends on a combination of interference fit, neck hardness, and the surface condition of the inside case neck and bullet surface.”

 

[Rsadams]

It will help on wet tumbled or new brass to stop cold welding....

 

[Jeff A]

I have been using Imperial as I wet tumble in SS Pins. I did a Side-by-Side test and my SD & ES were SLIGHTLY lower on the neck lubricated rounds, but I'm afraid the sample size on the test would render the results "Inconclusive".

 

[Joe Salt]

I've used Imperial dry lube for years, the reason i started using it was that it gives you a more consistent seating depth. As for E/S and S/D I don't think that is going to change. Worry about what it does on paper.

Joe Salt

 

[JimSC]

I tried various wet and dry neck lubes last summer, nothing too extensive but I did try a commercial dry lube and some home grown wet and dry lubes and noticed no difference whatsoever in my SD's. I have no way of measuring pull force in a laboratory under scientific conditions of course so take this with a grain of salt. But think about this, How much whatever pressure 2 or 3 thousandths of brass squeeze are putting on a fraction of a inch of bullet in the neck have any affect when you drop 50K plus of pressure behind it?

Bryan Litz in Modern Advancement II found that higher neck tension did not make any significant difference in muzzle velocity average but the SD's were lower with increased neck tension on the .223 and .243 tests and there was no appreciable difference on muzzle velocities.

When I added that with my own meager research I no longer neck lube and I get mostly single digit SD's on my established loads. Powder choice, and accurate powder load weight along with primer choice seems to have the most effect on lowering SD's as far as I can tell.

 

[Bart B.]

I have no way of measuring pull force in a laboratory under scientific conditions.......

Here's a way to get very close enough.

Prepare by filling several Ziploc bags incrementally with 1/4, 1/2, 1, 2, 4, 8 and 16 pounds of bullets. Weigh a collet type bullet puller, note its weight. You now have over 32 pounds of weight you can change in 4 ounce increments. Get a durable cloth bag with tie strings that holds the bullets and puller.

1. Drill a half inch hole in a 3/4" board, clamp it to the edge of a bench with the hole end several inches away from the edge.

2. Slip a bulleted case into a shell holder then put it onto that hole bullet down.

3. With the bullet puller, grip the bullet tightly.

4. Put some bags of bullets in the bag, attach it to the puller, then slowly let their weight pull down on the bullet.

5. If the weight of all that stuff doesn't pull the bullet, repeat with more bullets. Otherwise, add more bullets then try again.

If that weight pulled the bullet, remove some bullets, reseat the bullet then try again.

When the weight almost pulls out the bullet, slowly add more by hand until it pulls.


Or just dump bullets in the bag until it pulls.

 

[dmoran]

Here's a way to get very close enough.

I use a Grawor luggage/fish scale w/ tare weight hold function.
Cost around $10 and accurate to an ounce.

 

[eas1949]

I swizzle (with a cue-tip) the inside of the case necks with Neolube #2 after ultrasonic cleaning. It works great.

https://www.micromark.com/Neolube-2-fl-oz-

http://www.newmantools.com/chemicals/neo2pds.htm

Eric

 

[JimSC]

Thanks for the suggestion Bart however I have reached my goal of single digits with my velocity SD's and ES's so I don't plan to do any further ammo testing unless I change bullets. What I need to work on now is my shooting technique and wind calling not my ammo

 

[Bart B.]

There are several ways to skin a cat.

As long as you don't damage the cat.

 

[Bart B.]

I have reached my goal of single digits with my velocity SD's and ES's

Then pull force spread across all rounds is small, more important than what its average is.

 

[Bart B.]

Bryan Litz in Modern Advancement II found that higher neck tension did not make any significant difference in muzzle velocity average but the SD's were lower with increased neck tension on the .223 and .243 tests and there was no appreciable difference on muzzle velocities.

My tests with the same 308 Win load across a 1 to 30 pound pull force had over 40 fps average velocity spread.

Bullet jump distance effects velocity. Mine had about .060". Does Litz mention his?

 

[dmoran]

My tests with the same 308 Win load across a 1 to 30 pound pull force had over 40 fps average velocity spread.

That's excessive - IME. Likely a difference from how you clean and prep your necks compared to Litz, and others do. Can't help but feel if your getting that much ES across 30lbs of pull force, and inducing that much variation in pull from equal cases, you have some excessive friction issues, do to neck prep, or lack of. As per the topic of this thread; neck lube and/or other neck preparation steps could lower that ES issue, that optimally would aid in your seating force consistency, hence your amount of pull force and its ES.

 

[Bart B.]

Likely a difference from how you clean and prep your necks compared to Litz, and others

Nope. All cases had the same inside neck prep. Half had about .0015" smaller inside diameters sized in die necks about that much smaller. Those produced highest average velocity.

Same load, different grip force on bullets.

 

[BoydAllen]

One variable that may be involved is powders responding differently to neck tension. In short range we have run into this. Some time back, I was helping a fellow get up and running with his first 6PPC. In our discussions I found that he was using quite a bit of neck tension, something that seems to work well with 133, but he was shooting LT32, and it had been my experience that that powder did better with much less neck tension. Based on that, he increased the ID of the bushing that he was using, and eventually went to soft seating(loading longer than jam, so that the bullet is seated a little deeper as the round is chambered. His groups improved when he made those changes. Years before I had done the reverse when a friend suggested more neck tension for 133. My groups improved. I have a friend that gets excellent shooting Varget in a 6BRA with light neck tension. On the other hand for the H4895 that he favors for that caliber, I understand that one of the reasons that Tom Mosul does not anneal is because, for him, that powder does better with more neck tension.

 

[dmoran]

Nope. All cases had the same inside neck prep.

Which is more proof that you had an excessive friction issue, that could be remedied with different neck preparation steps and/or neck lube (as is the thread topic).

Personally, if I was getting 40-fps ES across 30-lbs of bullet pull, much less getting 30-lbs indifference in pull from equally neck prepped cases with only .0015" variation in neck tension, I would be attentive to find the reason for the excess, fallowed by changes in my neck prep and/or cleaning steps to resolve the issue. It's obvious to me you had/have an issue that caused that much friction indifference that created the excessive's.

Betting neck/bullet lube would help resolve your issue, but doubt in your case that it would be enough by itself. And have to think that something in your case cleaning, lubing, and/or neck preparations will need addressing as well.
Good Luck

 

[BoydAllen]

I just came back to this thread and saw an unintended bit in my last post...which I deleted (the bit, not the post). I must have hit an odd key while on a phone call. It was the text of a search that I had done.

 

[JimSC]

Bullet jump distance effects velocity. Mine had about .060". Does Litz mention his?

He was testing neck tension in that chapter so bullet jump was not addressed

I am using Erik Cortina's method of load development so yes I do address bullet jump in my own load development. My jump distance tweaks had what I would call a minor effect on velocity but it had a major effect on group size overall by reducing the number of horizontal flyers. For me the largest improvement I saw on lowering SD and ES were the powder choice and powder charge along with consistent and thorough case prep. Then I try a couple of different primers on the best load to see if I can tune it's numbers down lower. Once I am satisfied that the load will give me consistent single digits for 15+ shot groups I fine tune the bullet jump to tighten the groups up and cut down on flyers. Once again I am not a NRA record holder or expert on reloading and my meager experiments should be taken for what they are worth. Just because neck lube seemed to do nothing for me does not mean it won't work for others