Lube for new brass
- Thread starter RHux
- Start date
Rodger said:
How does "new" brass get carbon in the neck?
Rodger said:
Yes, I dip the necks of rifle brass in a jar of bird shot that is covered in graphite powder. The bird shot assures the graphite gets applied to the inside of the neck. Graphite on the inside of the neck does 2 things:
1. It provides lubrication for the expander button on the FL sizing die, and
2. Provides lubrication for bullet insertion and seating.
Joe Maisto
jam711
fdshuster said:
Expander buttons , (in my opinion) have become obsolete. If you need to expand a cartridge neck, use an expander die designed for that purpose only, and then get yourself a FL sizing die with button inserts to squeeze the neck to the size you need. It's what we do in benchrest shooting. They come in .001 increments as well , for more or less bullet tension.
jam711: I agree. The only reason an expander, ( of some type) must be used with non neck bushing dies, is because the case necks are being radically sized down, way more than is needed, so they then gotta be opened up to the correct inside diameter. Talk about overworking the brass !
Is it any wonder the case necks split sometimes after only a few loadings?
Is it any wonder the case necks split sometimes after only a few loadings?
Q: You believe consistent neck tension (i.e. grip on the bullet) is really important. What methods are you using to ensure consistent bullet release?
Henry: I apply Imperial dry neck lube to the inside of my case-necks with a bore mop. The K&M arbor with seating force gauge shows the need to do this. If you put a bullet into a clean case, it will be jerky when seating the bullet. You may see 40 units (on the K&M dial) dropping to 20, then slowly increasing pressure. I explained to a friend that not lubing the neck is like overhauling an engine without lubing the cylinders. Smooth entry gives the bullets a smooth release.
Henry: I apply Imperial dry neck lube to the inside of my case-necks with a bore mop. The K&M arbor with seating force gauge shows the need to do this. If you put a bullet into a clean case, it will be jerky when seating the bullet. You may see 40 units (on the K&M dial) dropping to 20, then slowly increasing pressure. I explained to a friend that not lubing the neck is like overhauling an engine without lubing the cylinders. Smooth entry gives the bullets a smooth release.
I was recently told by a Redding technician that I should dry lube the necks to improve seating bullets. I am using .002" neck tension and was amazed how easy the Nosler partition 130 gr bullets seated in Norma brass fired 4X. Also the tech said to put the neck sizing bushing in upside down or with the dimension side going in first. (Using Redding competition 3 die set). Now have 4 groups of 6 to test at the range. Any pro/con comments are welcomed!
I dip bullets in the dry neck lube. Cases get the powder and I don't want that stuff mixing or powder kernels rubbing it off when I dump em in.
shoot4fun
Gold $$ Contributor
I use Imperial Dry Lube in virgin brass or in cases where the die has an expander ball. Expander balls are not obsolete. I do agree that they are needed on Bushing type dies ONLY when the necks have been carefully turned to consistent thickness. If necks are not turned then the bushing pushes irregularities to the inside and can skew neck tension. The expander ball should keep the inside of the neck consistent. Below is copied from Redding website:
Question: Do I need to use the expander button that came with my Type "S" Die?
Answer: It is advisable to use an expander button to maintain consistent neck tension if the case necks have not been turned to a uniform wall thickness. However, the expander button can be replaced with the Decapping Pin Retainer (included with your Type "S" Die) if the user does not wish to use an expander button.
Question: Do I need to use the expander button that came with my Type "S" Die?
Answer: It is advisable to use an expander button to maintain consistent neck tension if the case necks have not been turned to a uniform wall thickness. However, the expander button can be replaced with the Decapping Pin Retainer (included with your Type "S" Die) if the user does not wish to use an expander button.
I agree with you in that until you have the carbon layer inside necks, seating forces will be all over the map.
But IMO, the only purpose for new brass is a beginning. Once fire-formed they'll have a nice carbon layer.
Also, neck tension & bullet release is independent of neck friction/seating forces.
A bullet is 'released' with neck expansion under firing pressure. It's a hard concept to accept, but think about it this way: if a neck gripping a bullet expands only a trillionth of an inch(i.e. ANY amount), it has fully released a bullet. It takes way more pressure to move the released bullet mass of it's own, than to cause it's release. So when a bullet is released, it's still takes time for it to freely accelerate out of the neck.
If a condition forced seating friction to be overcome for bullet release, that bullet would move very little -in front of the exploding action!
So if it takes so little to release a bullet, how can tension variance matter? It's because the pressure curve is building so fast that everything else takes longer to occur -and yet everything else contributes to the final peak & timing of it.
You can do a test here & now to see it. All bullets seated off the lands OTL. Your K&M will help.
test #1
-Polish 5 new(but chamfered) necks squeaky clean, size/seat and note high seating forces.
-Take 5 other new/chamfered necks, dry burnish in a shiny layer of tungsten disulfide(WS2), size/seat and note low seating forces.
Fire them across a good chronograph, and note no difference in MV. Friction didn't matter.
test #2
-With 5 new necks bushing size .200"length of necks, seat and note seating forces.
-Size 5 others only .100" length of necks, seat and note seating forces.
Fire them across a good chronograph, and note significant difference in MV. Tension(grip) does matter.
If setup to do so there is a test #3, where you could fit for very little neck clearance (~.0001) -VS- a lot of clearance (~.002), and a chrono would show no difference in MV.
.0001", where you can manage, might as well be a mile of neck clearance.
If there are more reasons than that I haven't found one.
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