Forums
New posts
Search forums
What's new
Articles
Latest reviews
Author list
Classifieds
Log in
Register
What's new
Search
Search
Search titles and first posts only
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Rifles, Reloading, Optics, Equipment
Reloading
Neck clean-up, cutting depth?
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="lynn" data-source="post: 72839" data-attributes="member: 1479"><p>ArthurJTo get concentric necks which is what you are after they must be cleaned up 100%.If you only clean them up 80% of the way that means 20% of the brass is a different thickness so why bother at all? There is no sense in doing a half *** job and later trying to correct for bad habits learned on a loose chamber.Start by necking down a piece of brass then expanding it back up with the mandrel.This will ensure all your necks have the same pre-load on them.You need to liberally coat the mandrel and inside of your necks with Imperial Sizing Die Wax or Automatic transmission fluid mixed with STP (2 to 1)oil treatment.Do a quick cut on a piece of brass that will be sacrifised that cleans up the neck 90%.From there adjust the tool in very small increments until that piece of brass is 100% cleaned up.This piece of brass should be done by hand and you should keep applying lubricant so it spins freely and to avoid heat build up.Wait atleast a half hour and re-run it on the turner without changing anything.If you feel tight spots are places were it feels like it is dragging on one spot keep turning it until this becomes silky smooth.These are little ridges or high spots.Did i mention that lubrication is very important.This dragging will be felt on your initial cut even with proper lubricant but it shouldn't be felt after your final cut.You also need an old toothbrush to keep the chips from trying to go through the cutter and galling your brass.Keep the chips brushed away at all times.The outside of that one case should look shiny smooth.Measure that case now and see what it measures.Now seat a 30 caliber boattail bullet(no pressure ring) and pull that bullet back out and measure it again.Alot of people skip that step and there brass comes up too loose in the chamber.On typical 30 caliber brass using a bullet that measures 0.3080 you would add twice your neck thickness plus the bullets diameter to get something like this. 0.308 + 0.013 + 0.013 = 0.334 which would work well if you had a 0.335 or 0.336 tight neck chamber which is very common.If you had a 0.332 tight neck chamber your brass would need to be turned thinner.On a factory chamber i would clean it up 100% measure it and record the thickness.You can now do your initial turning under power and your final cut by hand.When done i usually use 0000 steel wool on the outside for a mirror smooth finish.If your under power you can put some steel wool on a worn out cleaning brush and run it inside the necks with a little Flitz metal polish on it to get the inside very smooth as well.Remember the lubricant and touch the mandrel that the neck rides on against your lip.If it is hot to the touch your going to fast.Slow down or let it cool.This is important on the final cut.Lynn</p></blockquote><p></p>
[QUOTE="lynn, post: 72839, member: 1479"] ArthurJTo get concentric necks which is what you are after they must be cleaned up 100%.If you only clean them up 80% of the way that means 20% of the brass is a different thickness so why bother at all? There is no sense in doing a half *** job and later trying to correct for bad habits learned on a loose chamber.Start by necking down a piece of brass then expanding it back up with the mandrel.This will ensure all your necks have the same pre-load on them.You need to liberally coat the mandrel and inside of your necks with Imperial Sizing Die Wax or Automatic transmission fluid mixed with STP (2 to 1)oil treatment.Do a quick cut on a piece of brass that will be sacrifised that cleans up the neck 90%.From there adjust the tool in very small increments until that piece of brass is 100% cleaned up.This piece of brass should be done by hand and you should keep applying lubricant so it spins freely and to avoid heat build up.Wait atleast a half hour and re-run it on the turner without changing anything.If you feel tight spots are places were it feels like it is dragging on one spot keep turning it until this becomes silky smooth.These are little ridges or high spots.Did i mention that lubrication is very important.This dragging will be felt on your initial cut even with proper lubricant but it shouldn't be felt after your final cut.You also need an old toothbrush to keep the chips from trying to go through the cutter and galling your brass.Keep the chips brushed away at all times.The outside of that one case should look shiny smooth.Measure that case now and see what it measures.Now seat a 30 caliber boattail bullet(no pressure ring) and pull that bullet back out and measure it again.Alot of people skip that step and there brass comes up too loose in the chamber.On typical 30 caliber brass using a bullet that measures 0.3080 you would add twice your neck thickness plus the bullets diameter to get something like this. 0.308 + 0.013 + 0.013 = 0.334 which would work well if you had a 0.335 or 0.336 tight neck chamber which is very common.If you had a 0.332 tight neck chamber your brass would need to be turned thinner.On a factory chamber i would clean it up 100% measure it and record the thickness.You can now do your initial turning under power and your final cut by hand.When done i usually use 0000 steel wool on the outside for a mirror smooth finish.If your under power you can put some steel wool on a worn out cleaning brush and run it inside the necks with a little Flitz metal polish on it to get the inside very smooth as well.Remember the lubricant and touch the mandrel that the neck rides on against your lip.If it is hot to the touch your going to fast.Slow down or let it cool.This is important on the final cut.Lynn [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Rifles, Reloading, Optics, Equipment
Reloading
Neck clean-up, cutting depth?
Top