Neck Turning Mesurement .223

[Fotheringill]

I tried to find this in the archives, but was unsuccessful.

New Lapua brass, .223. What thickness should I turn the brass down to?

 

[AlNyhus]

Impossible to say without knowing the neck diameter of the chamber.

 

[AJC]

Are you just trying to skim cut to make the neck even. I was also considering my setting but have not measured all my pieces. The Samir spec number for thickness I came up with is .01265 so skimming to .012 seems like a good idea. Very intrested in what you end up doing. If I dont have any inconsistencies I'll leave my lapua alone.

 

[Richard Coody]

what are you trying to accomplish?

surely this is not a bench rifle?

 

[AJC]

what are you trying to accomplish?

surely this is not a bench rifle?

Mine is. I shoot metal siloett to 600. My first gun for this practice.

 

[Richard Coody]

Mine is. I shoot metal siloett to 600. My first gun for this practice.

well what i would do is skim trim a few pieces turn at least.75% of the neck. measure the neck thickness on them and pick the thinnest and use that for the thickness of the entire batch. with lapua brass in 6br i found neck variations of up to 0.0015 measuring at different points around the neck. cleaning them up helps with concentricity and consistent neck tension.

if you are taking this to this level may i make a few recommends

first and foremost. accurate powder charges. best i found was adam's autotrickler system

if you are going to go to the trouble to turn necks then you want the most consistent neck tension possible. a high quality bushing die and a set of k&m expander mandrels in 0.0005 increments will allow you to find the neck tension that your rifle/barrel/powder/bullet prefers. need the 21st century hydro press and wilson dies to learn what it takes for consistent neck tension

lots of load development to find that magic combination

lots more but that will get you started down the rabbit hole.

 

[AJC]

well what i would do is skim trim a few pieces turn at least.75% of the neck. measure the neck thickness on them and pick the thinnest and use that for the thickness of the entire batch. with lapua brass in 6br i found neck variations of up to 0.0015 measuring at different points around the neck. cleaning them up helps with concentricity and consistent neck tension.

if you are taking this to this level may i make a few recommends

first and foremost. accurate powder charges. best i found was adam's autotrickler system

if you are going to go to the trouble to turn necks then you want the most consistent neck tension possible. a high quality bushing die and a set of k&m expander mandrels in 0.0005 increments will allow you to find the neck tension that your rifle/barrel/powder/bullet prefers. need the 21st century hydro press and wilson dies to learn what it takes for consistent neck tension

lots of load development to find that magic combination

lots more but that will get you started down the rabbit hole.

Right now i am testing bullets and plan on using my rcbs chargemaster for loads. Right now i am going to stay with 24.4 of varget until i find a good seating depth and a bullet that i like. The 80 eldx's are ok for now on my first match ever i got 39 out of 50 targets. This is the setup my dad came up with before he passed and what i am starting with. We never ran a seating test so that will be my first big step. I want to remeasure the lands with the hornaday tool, i just got and do the vld test that burger put out. I have never shot paper to see how well or consistant this load is so of the remaining 50 rounds he loaded thats my plan. I hope to use those for a seating test. He was using a regular set of rcbs dies, and i plan on going to the forester honed dies with the pin mandrel set to play with neck tension. I may be way off but the bushings dont appeal to me at this point because of that unsized section. I plan to order my dies either -.003 or -.004 considering is should get .001 spring back then i will not have to move it far for a final adjustment keeping the brass working to a minimum. These plans will all commence in july when i get done with my move and unpacked again. I will be retired and able to dedicate myself to focus on this new project completely.

 

[Richard Coody]

great retirement project and the begining of quite a learning experience.

get you an "accurate" beam or electronic scale to check those chargemaster charges. throwing short and trickling will probably be where you wind up

 

[savagedasher]

Turning necks should be done depending on the reamer used
If it isn’t a custom chamber turning neck only make you working the brass more

 

[Richard Coody]

Turning necks should be done depending on the reamer used
If it isn’t a custom chamber turning neck only make you working the brass more

opinions vary

i believe uniforming neck thickness in a batch of brass helps with concentricity and consistent neck tension

now do i do it with hunting and plinking ammo? no

but for precision ammo i believe it is pretty common

 

[savagedasher]

opinions vary

i believe uniforming neck thickness in a batch of brass helps with concentricity and consistent neck tension

now do i do it with hunting and plinking ammo? no

but for precision ammo i believe it is pretty common

Just remember when you take neck thickness away the brass must expand to take up the clearance
Without a custom neck I don’t think you will see the difference

 

[AJC]

Just remember when you take neck thickness away the brass must expand to take up the clearance
Without a custom neck I don’t think you will see the difference

So based on this idea then technically your working the brass more each firing cycle. Then begs the question which is more important consistant neck thickness or working the brass.

 

[AlNyhus]

So based on this idea then technically your working the brass more each firing cycle. Then begs the question which is more important consistant neck thickness or working the brass.

And....we're back to my original question.

 

[AJC]

And....we're back to my original question.

I would guess the neck thickness consistency would be most important because is is part of the holy triad including neck tension, but thats swag

 

[Richard Coody]

well like most things in shooting there are lots of ways to skin this cat. whatever works for you.

we can look at it this way. what you mean by working the neck is the difference between loaded round diameter and the chamber neck diameter? at least i think that is what you are talking about. benchrest shooters strive for .003 difference. of course some think less clearance is better and some want a little more. i have never read any discussion about overworking the brass with excessive clearance. now i am curious about that.

how about you post the difference between a loaded round and a fired case. figuring at least a .001 of springback we can get a pretty close approximation of.clearance.

you are saying trimming 0.0005 to .001 off the neck will result in too much clearance thereby overworking the brass upon firing. maybe

but for me the consistency of neck thickness is more important in precision ammo than brass life. my brass doesn't die from split necks but loose primer pockets.