Neck size and lubricants

[ronzi83]

Hello everyone, long time i didnt post anything, so today i would like to ask you for your experience in lubricants. Will it effect on neck tention if i use lub on one case and not on another? Will give me any value or just beter /smoother sizing? What lub do you use for inside case and how you clean it off? I was thinking to use just graphit powder and div case neck in to it. 

Regards

 

Ronzi 

[maximus otter]

1 hour ago, ronzi83 said:

What lub do you use for inside case and how you clean it off?

 

a)

 

 

b) I don't.

maximus otter

[Popsbengo]

1 hour ago, ronzi83 said:

Hello everyone, long time i didnt post anything, so today i would like to ask you for your experience in lubricants. Will it effect on neck tention if i use lub on one case and not on another? Will give me any value or just beter /smoother sizing? What lub do you use for inside case and how you clean it off? I was thinking to use just graphit powder and div case neck in to it. 

Regards

 

Ronzi 

Neck tension may be the same with or without lube but it's also the friction between bullet and neck that matters so lubricating the bullet or the neck will affect release and therefore combustion progress and that affects velocity.  If you can ensure tension and lubrication (eg coated bullet) are consistent then velocity should be too (all else being equal).  A lubed bullet normally has a lower Mv for the same charge weight of powder due to combustion progressing differently as the initial pressure (as well as friction in the barrel) to release the bullet and start it moving is lower- this is often compensated by increasing the load.

So, it's not just tension that matters, the surface condition of the neck (ie how shiny or polished/rough) is also factor.  For example, ultrasonic cleaning may result in a roughened surface.  I u/s clean but I also dry tumble to polish the case and wipe out any dust, as it's abrasive.

I use sizing lube in the neck when driving a mandrel in, it protects the surfaces of the mandrel and neck from micro scratches.  It wipes out really easy with a damp Q tip leaving a sized, dry reasonably polished neck and judging from bullet seating with an in-line die very consistent neck pressure and very consistent Mv

Some loaders advocate crimping as this can equalise release pressures  - the crimp has a far greater effect than neck tension/lubrication alone.

I should also mention that un-annealed necks will ultimately become very variable in tension as the brass work hardens to differing amounts.  This pretty much cocks up any attempts to equalise neck pressure - hence why annealing is recommended for precision shooting.

[Richiew]

Same as maximus  otter 

dry lube and wipe outside of case after sizing . Only dip the neck in the media though . I’ve found that sako 223 cases are rather rough so they hold a lot of media and bung the die up a bit - less is more !! .

I bought the dry media 5 years back and have only just topped it up with new graphite from the same maker (2500+) 308sloaded to date . 
cheers