Lube bullets before seating?

S

Stats Shooter

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A while back we had a thread that discussed neck tension, still other threads have discussed crimping. The desired result for most hand loaders is enough neck tension to keep the bullet from unseating while maintaining consistency. "enough" neck tension is of course a relative term and while enough may be very little neck tension in a single shot target rifle, much more neck tension may be needed in tubular magazines in calibers such as .45-70.
For the most part, we all do different things to ensure consistent neck tension such as sorting brass lots, making sure that each piece of brass in a particular load group has been fired the same amount of times, annealing, trimming, chamfering etc.

But I decided to try something else, something I didn't find a lot of talk about, which is lubing the bullets when seating them. I know that it is common with respect to cast bullets, but in jacketed factory bullets, it does not seem to be common.

One of the problems I have is that I use a steel pin wet tumbler. While it gets the brass squeaky clean inside and out, it may in fact get the neck too clean increasing the friction between the brass and the bullet. With some of my cartridges, despite doing everything mentioned in the first paragraph, I noticed considerably more effort needed to seat some bullets vs others. Indeed, I pulled some previously seated bullets to see what was happening an noticed some were scraped up more than others, with portions of the jackets being scraped off. These were boat tail's mind you and not flat base.

It is likely that someone who does not tumble their brass would never have this issue because they likely do not remove all of the case lube thereby lubing the neck before hand so to speak. However in my case, all the lube and remaining residue from firing is totally gone.

So I decided to try lubing the bullets as I seated them. I did 3 test lots, 20 rounds each. The first lot was the control where I did not use any lube. The second lot I used a viscous "wet" lube where I put a thin ring of lube at the bottom of the ogive just above the boat tail. In the third test lot I used talcum powder coating just below, and above, the bottom of the ogive.

Here is what I found relative to the control
Wet Lube:
Average velocity -7 fps
Standard deviation 4 fps compared to 21 fps for control

Dry Lube:
Average velocity -4 fps
Standard deviation 9 fps compared to 21 fps for control

Now I realize that introducing a damp material to a cartridge with powder already in it may not be the best idea....especially if this ammo is going to be stored for a long-ish period of time. But I highly doubt much of the material made it down into the powder. Also, if that is a concern, the dry lube gave good results too and obviously wouldn't dampen the powder.

One may question weather it is worth it, but a standard deviation of 21 fps mans that the spread between 68% of the bullets is as high as 42 fps. And in a round averaging 2750 fps, that is 2771 for some and 2729 for others...and if you use the 68,95,99.7 rule from statistics, in the control, 99.7% of the rounds are between 2687 and 2813. The wet lube on the other hand averages 2743 with 99.7% between 2755 and 2731!..now that is consistency, where the wet lubed bullets are more consistent in 3 standard deviations than the no lube bullets are within 1 standard deviation. Of course the dry lube is in between both extremes.

So, while I'm not suggesting that this is a good practice for all applications, especially not semi-auto handgun or heavy recoiling tube magazine rifles. If you have done everything stated in paragraph 1 and would like to try and reduce the standard deviation further, lubing the bullet might just help.
 
Nice piece of work! Thanks for posting it.

Take a look at this article. I've been told the Froggy's Lube mentioned is no longer available to purchase, but that it is just graphite in alcohol. The step of brushing the inside of the case mouth will scuff the surface enough to eliminated polished surface friction. Polished surfaces can present uneven contact and the scuffing will randomize it enough to tend to average errors out.
 
Back in the olden days when we all used a lube pad or non-inked stamp pad to lube our cases, many of us would roll a nylon bore brush on the pad and then insert the brush into the case neck to lube the inside of the neck. One or two rolls of the brush on the pad was good for five to ten cases.

Later, Lyman came out with a little gizmo that had various size nylon brushes anchored in a vertical position inside a plastic box filled with finely ground mica particles. Idea was to lube the inside of the case mouth with a dry lube to avoid (allegedly) powder contamination. Shake the box to get the mica on the brushes and then insert the case mouth over the brush. I've still got one and it did not work as well as the old lube pad/ brush method.

I have lubed thousands of case necks with the pad/nylon brush method and have yet to have a powder contamination issue. I still use this method on all the cases I have cleaned in my SS pin tumbler. With 50 cases standing up in a loading block, one quick pass with the lubed nylon brush takes very little time. Just don't get the brush drippy wet with lube -- one or two rolls across a lube pad is fine and good for several case mouths.

As a final note, back then I was using a petroleum based lube on the lube pad and still do. I don't know what some of the modern liquid lubes will do if not petroleum based. If you can't find one you might try 90 weight gear oil (boat lower case outboard motor lube) or STP oil treatment. I still have several tubes of the first (original) RCBS case lube left, so I've not experimented with any of the new liquid lubes.
 
MKL:
My only concern with respect to lubing the neck vs lubing the bullet is this: if I lube the bullet, any excess lube is pushed up and out, where if I lube the neck, it is pushed down and in. If your method has worked for decades, then obviously don't change a thing. But that was my thoughts when I chose to lube the bullet rather than the neck.
 
MKL:
My only concern with respect to lubing the neck vs lubing the bullet is this: if I lube the bullet, any excess lube is pushed up and out, where if I lube the neck, it is pushed down and in.
Click to expand...

Good point. I never considered that, just that I have never had a misfire using the inside neck method. Also, I never ran the with/without loads over a chronograph like you did.

Would be interesting if you did a bullet lube vs a neck mouth lube test over your chronograph after the cartridges had set a year or so. I suppose it is possible I had some powder contamination and never noticed it since I never chronographed the loads.
 
The same thought has crossed my mind though its directed at new brass.

Normally my shooting brass is once fired.

But I do have some good brass (Lapua) and what I had seen with it and PPU (seems about RP class) is that the new brass the bullet seating is erratic for tensions.

This is with Lapua, some slide in like once fire, others take a push.

This is with boat tail bullet and a chamfered case mouth.

So, I have Hornady luge that they say does not react with power, I am going to load up some with lube on the bullet side (not the boat tail or the bottom) and see how they do.

I won't have FPS data, but I can feel the slide in difference and will see if there is any accuracy change.

Its a once off as after the first shooting the neck tension feels the same as long as I anneal once every 5 rounds.
 


The above is a 10 shot string from 100 yards using my wet lubed bullets shot through corney to get velocity.
.223 75 grain BTHP
62 degrees, 1-3 mph wind
Lake city brass, Varget powder

From the gun below



As far as lubing the neck vs the bullet, I'm not sure I would need to wait a year. A few months would likely be enough. And I'm not sure how much difference it makes. There was a tiny bit of residue on the rim off the neck when I seated the bullets that I simply wiped off, but it wasn't much.
 
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I occurs to me to mention this is also supposed to be a benefit from coating bullets with moly or hBN. I discovered, however, that when you chamfer a case after trimming, the edge left by that operation can actually scrape all the moly off a bullet, and it comes out the color of copper on the bearing surface if you pull it afteward. So you have to burnish the chamfered edge to prevent that. I did it with a hard wood dowel sharpened like a pencil and spinning in my drill press, but those sticks didn't last long. Then Bart Bobbit put me onto the idea of polishing up an E-Z Out's coarse left hand thread, and that works and lasts. After burnishing with that the coating remains intact during seating.

I've not tried the hBN coating, but presume something similar would occur with it.
 
Unclenick:

Something else I just thought of as well, my losses, albeit small, in velocity may not actually be a loss at all. The lubed bullets may be the "true" average while the unlubed bullets give more erratic average velocities given their high standard deviation. Had I shot 1000 rounds over a chroney of lubed and nonlubed bullets, the average may be identical, but with much higher standard deviation.

I only say this because I do not want to give the impression that my test says lubing your bullets will reduce velocity. But, the drop in standard deviation is significant enough and you can certainly tell when you operate the press which are lubed and which are not.
 
Losses are normal with lubrication. It's the reduced start pressure that's responsible. Moly-coated bullets drop 20-50 fps in MV, but there is isn't just start pressure but resistance all the way down the bore that is making it harder for the powder to burn. In that case it's no problem adding a little powder to make that up. In your case the difference is so small you can ignore it.
 
Sort of an aside and question for Mississippi, or anyone else; my method to lube case necks is a pill bottle full of air gun BBs and graphite. Plain old black graphite. I just push the cases in the BBs a couple times and size. How would this method affect bullet seating/neck tension? Your thoughts?
 
Right unclenick,

Lubing a small portion of the bullet isnt the same as Molly coating...so perhaps my velocity loss is real, but small since I'm only really reducing the pressure required to unseat the bullet, it likely doesn't extend all the way down the bore
 
I have lube equipment for lead bullets, but when loading bottle neck cases I do not want anything between the case and chamber but air, I do not want a lot or air just a little and then there is clean air; I prefer clean air.

Next is the bullet in the barrel, I do not want anything between the bullet and the rifling/barrel; because if there is anything in front of the bullet when the trigger is pulled and if it does not get out of the way the bullet has to pass it. Again, I do not want anything between the case and chamber and I do not want anything in the barrel the bullet has to pass.

And then there is neck tension, no one can measure neck tension because no one builds a tension gage. I have tension gages; all of my tension gages are calibrated to pounds, and that leaves me with no way to convert pounds to tensions. I do have bullet hold, I am the fan of bullet hold, bullet hold is measured in pounds.

F, Guffey
 
however, that when you chamfer a case after trimming, the edge left by that operation can actually scrape all the moly off a bullet, and it comes out the color of copper on the bearing surface
Click to expand...

but there is isn't just start pressure but resistance all the way down the bore
Click to expand...

Maybe I'm missing something but how can these two quotes be accurate ? If simply seating a bullet removes the moly . How is the moly "not" removed when it slams into the rifling and scrapes down the bore ?

Now I've never used moly coated bullet because of the roomer the moly gets left in the bore and is almost impossible to get out . This would seem to indicate the coating is actually at least partially remove from the bullet early in the bullets travels . If so would it also be reasonable to conclude lubing your regular bullets will ultimately do the same thing with out leaving the moly coating in the bore .

Or even just soft seating the bullet ? Meaning your bullet hold is just enough to not let the bullet fall out of the neck . I know guys that say they seat there bullets very long with very little bullet hold and let the rifling seat the bullet deeper when they close the bolt .
 
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Metal god:

My guess would be that with molly coated bullets, if it is being run across a smooth edge, like the bore, the molly coating stays on better than scraping it against a sharp edge. I truly do not know how much molly is left once the bullet leaves the barrel and I have never used molly bullets.

But, I do know that seating bullets with dry or wet lube helps with consistent seating and reduces the standard deviation.
 
I lubed the inside of the cases.

Much more uniform seating but you could still feel the variation in my never fired cases.

First bunch I was dumb and lubed before I put the powder in, not as bad as it sounds but not the way to go.

The rest I lubed after the powder went in.

Not sure its any help, still chewing on results.

The cases are chamfered in a TriTrimmer.
 
I had to go back and read UN post . It states

when you chamfer a case after trimming, the edge left by that operation can actually scrape all the moly off
Click to expand...

My understanding of chamfer is to put a angle on the inside lip of the case mouth rather then it being a perfect 90 degrees . Logically you'd think that would reduce any friction as it works like a funnel allowing the bullet to be eased into the neck rather then being scraped along a right angle .

hmm , never thought about flaring the neck though . That would allow the bullet to slide in there easier . How many guys flare there rifle case mouths ? I never have but I load on a single stage or turret press .
 
Volatile aspects of the wet lube are going to cook off over time and you may end up over the long term with more variability than if you'd gone dry or with nothing.
 
30CAL: Volatile aspects of the wet lube are going to cook off over time and you may end up over the long term with more variability than if you'd gone dry or with nothing.
Click to expand...

So I guess that is a vote for dry lube?
 
While I cannot say I use it,I have a small tin of dry neck lube.I think it is offered by Imperial sizing wax.
I have a different theory what may be happening.
Brass is very mallable.The pins may be causing a slight mushrooming of the brass at the case mouth.That would create a scraping edge.
A quick twist with a VLD chamfer tool might help.

It would make sense to pin clean the brass before sizing.Then a light twist of chamfer tool.I would expect the sizing expander ball to somewhat burnish and clean up the neck ID.Carbide expander balls are nice.Hornady sells a kit to fit RCBS dies.
 
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