Extreme Velocity Spread Question - I'm perplexed

[shepardsonp]

Dry neck lube will make the difference, I gave it a try after reading some one doing it, don't quote me but I think it was Carlock with a 338Edge. I don't use it anymore and started annealing to maintain consistent bullet release.

i am heading to Shawn's advanced LR class July 12 & 13th in Idaho. I purchased his Reloading for Long Range Hunting Video - watching it at least 10 times and followed the instructions to a T. I didn't think the neck lube would be a big deal - maybe it is. I hope so - that way i may have found out the problem.

 

[Pdvdh]

i am heading to Shawn's advanced LR class July 12 & 13th in Idaho. I purchased his Reloading for Long Range Hunting Video - watching it at least 10 times and followed the instructions to a T. I didn't think the neck lube would be a big deal - maybe it is. I hope so - that way i may have found out the problem.

I've always believed that varying neck tension can affect the consistency of powder ignition/combustion. Lubing the necks would be the equivalent of decreasing bullet to case neck tension - to my way of thinking.

I've ultrasonic cleaned some brass in the past. When I load bullets into the necks of these ultrasonic cleaned case necks, the bullet seating force is incredibly increased. I now use a very light coating of Imperial Case wax/lube inside the case necks of any ultrasonic cleaned cases prior to powder charging the cases. Bullet slips in there like greased lightening - in comparison to the dry case necks. I use a Q-tip to coat the interior of the case neck, and then a dry Q-tip to remove any excess Imperial Case wax.

I was experiencing differing MVs between the dry case neck and lubed case neck reloads over the chronographs.

 

[Mikecr]

Lube shouldn't make any difference at all.
Neck tension is not directly represented by the force it takes to seat bullets. There is friction as well. But this does not come into play with bullet release on firing. Neck expansion from pressure allows bullet release, before it even moves.
Neck lubing allows easier seating, which should provide more consistent seating, if the plug is pushing too hard against the angled bullet nose. But when this is the case, you're not sizing necks correctly.

Neck TENSION is purely a matter of it's springback, which is limited to ~1.5thou(per side) with very very hard brass. You'll note that others have solved the 'problem' of varying seating pressure with annealing. Well, annealing doesn't make necks slippery. It normalizes & reduces springback, and so tension variances.

Phorwath, there is no need to use wax in the necks. There is no need to lube necks.
Just size them correctly, with an occasional annealing, and all will be gripped consistently.

 

[Pdvdh]

Mike,
I'm sure the ultasonic cleaning simply changed the coefficient of friction between the bullet and the interior case neck. It was a real surprise when seating the first bullet - a greatly increased force on the press handle required to seat bullet. The next thing I encountered was the need to screw down the micrometer seating depth adjustment on the Redding Competition seating die substantially to obtain the same case head to Ogive length on the seated bullets - compared to fired cases without the ultrasonic cleaning.

I've about decided ultrasonic cleaning is more trouble than it's worth. I don't tumble, vibrate, or ultrasonic clean any brass any longer. Other than if I find some pickups in the field with some dirt or corrosion on them - pretty much solely for use in the AR-15 or pistol/revolvers. I'll ultrasonic clean them. But I still Imperial wax the case necks prior to the first powder charging to reduce bullet seating force.

Edit addition: Except for my Ruger Alaskan .454 Casull. If I Imperial waxed those case necks, all the remaining loads in the cylinder would jump there crimp and leave me with a jammed revolver and a single shot revolver...

 

[shepardsonp]

Any tips on the annealing process and how you do it consistently?

 

[bigngreen]

The neck tension will remain the same but the friction can be altered which will change bullet release. What every a guy does you just have to do it consistently while developing a load and keep it the same from there on out.

 

[Pdvdh]

Any tips on the annealing process and how you do it consistently?

There are some write-ups on the method on this Forum. It's a matter of obtaining the proper duration of application of the heat, which is dependent on the temperature of the torch flame. Gotta get the case neck shoulder joint up to around 650F quickly, without allowing the case head to ever get heated up. Also, if you overcook the case neck the brass case can be ruined.

There too much to write up on my method to take the time at this moment, but I basically spin the cartridge case in a battery powered drill, holding the case head in a Lee case head holder chucked into the drill. I use a 3/4" long focused blue propane torch length. Spin the casing while holding the case neck/shoulder joint at the tip of the darker blue flame for 5 1/2 seconds. Quickly remove the casing from the flame tip and drop the case into a container of cold water. I keep a large clock with a second hand visible behind the torch flame so I can watch the second hand while spinning the case neck in the flame.

Research the subject and practice on some reject brass before launching into your good brass. You'll have to devote at least one hour to researching the subject before you'll be prepared to begin annealing. That was my experience. You'll find articles on the topic if you run a Google search.

 

[trebark]

i am heading to Shawn's advanced LR class July 12 & 13th in Idaho. I purchased his Reloading for Long Range Hunting Video - watching it at least 10 times and followed the instructions to a T. I didn't think the neck lube would be a big deal - maybe it is. I hope so - that way i may have found out the problem.

phorwath gave you the test you need to run to determine if the dry-lube is the culprit.

 

[Mikecr]

The neck expands enough to release a bullet(.0001) before the bullet actually begins to move. The escaping gas(around the bullet, and before neck sealing) scours the throat and soots the outside of necks.
So it doesn't matter to peak pressure, throat life, or neck sooting, that you coat bullets or not.

Actual neck tension matters to peak pressure, and neck sooting(depending on clearances). You can run an independent test over a chrono to see it.

 

[Pdvdh]

Mike,

You could be absolutely correct. I admit I didn't shoot enough bullets over my chronographs to reach any confident conclusion. Nor have I performed any exhaustive research on the subject. Your perspective is interesting - if not a little counter-intuitive. However I will admit I've learned to respect your knowledge over the years from reading your Posts on this Forum. You've confirmed or corrected a thing or two in the past for me when I wasn't really certain.

Either way, I'm a finicky kinda guy, and I like to load all my rounds the same way. I'd probably lose sleep if I didn't load them all 'exactly' the same way...

 

[Mikecr]

Only tryin to help.
I really don't think his ES has changed over neck lube.
It seems to me that it could come down to a small chrono sample size -earlier.
His chrono is a good one. But he doesn't have your 'MegaChrono' validation!

ES can be one of the toughest issues to solve..

 

[djtjr]

i think that you are being meticulous enough that it doesn't have to do with procedures but sample size and basic statistics. a sample size of 5 vs 13 is very different statistically speaking the larger you sample size the better typically if you have 1 round that is way off discard it as an outlier which you mentioned and got an es that statistically is a lot closer between the two strings.
d

 

[Boss Hoss]

Edited

 

[rscott5028]

Like djtjr said, 5 shots is a very poor statistical predictor of future performance

and, ES is an even poorer way to measure

nothing changed

you just got lucky on the first batch

Shoot some more paying particular attention to suggestions like Boss Hoss and others pointed out.

-- richard