centershot
Silver $$ Contributor
What is the proper amount of clearance on a turned neck? .001", equaling .002" diameter?
What Neck Clearance When You Turn 6PPC Brass
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Dusty Stevens
Shiner
I turn to .0085 to .0087 for a 262nk and around .0112-.0115 for a 268nk. it all matters in your bullet pressure ring measurement so you may not get good info here. all I can tell you is if a bullet wont slip into a fired round turn off some more.
I turn the customers brass for .002 clearance using the customers supplied bullet. As @Dusty Stevens said, the pressure ring matters.
i hope this helps,
Lloyd
i hope this helps,
Lloyd
Ccrider
Gold $$ Contributor
I have read a lots trying to find the correct answer to this question. I have seen from.080-.086 recommended. I finally decided that the fired brass and target will tell you how much to trim. If you have a solid line around your neck after firing, you have not trimmed enough. Trim too much and you will see the carbon on your shoulders but no wavey patten on your neck. Just right and you seem to get a consistent wavey pattern around the neck.
Most importantly, if all shots go into the same hole, you know you probably got something right.
Most importantly, if all shots go into the same hole, you know you probably got something right.
Dusty Stevens
Shiner
Youll only get 2 waveys on the neck if its right, unless you have a 3 lug action
centershot
Silver $$ Contributor
Thanks for the input.
After trial and error of trying my hand and drill press and anything else my creative mind could come up with, I eventually stopped trying to turn my own case necks. I talked to Bruno Shooting Supply over phone the first time I ordered pre turned 6ppc cases as I did not know chit from shino. I do not remember the gentlemans name, but he is very helpful and I could not be happier with the cases. I now buy my Lapua brass already turned from them and they are always perfect and professional looking. Well worth the price.
As for dimensions, when loaded, the case necks are .260" O.D.. My barrel is reamed to .262". My action is a factory Sako, so I do not load anything except what is printed and approved safe by the powder companies.This might be from the load data books, a phone conversation with one of the techs, or an email, but its always from the company of the powder I am going to try or use. With this said, I think if you reload from a reloading book, like myself, the .002" clearance works perfect. Now if your action is a custom action and you are planning on maxing the capacity of the cases to reach the higher nodes, you may want to consider .003" clearance. But I have no experience with custom actions and this is just knowledge I have picked up from reading up on the 6ppc.
As for dimensions, when loaded, the case necks are .260" O.D.. My barrel is reamed to .262". My action is a factory Sako, so I do not load anything except what is printed and approved safe by the powder companies.This might be from the load data books, a phone conversation with one of the techs, or an email, but its always from the company of the powder I am going to try or use. With this said, I think if you reload from a reloading book, like myself, the .002" clearance works perfect. Now if your action is a custom action and you are planning on maxing the capacity of the cases to reach the higher nodes, you may want to consider .003" clearance. But I have no experience with custom actions and this is just knowledge I have picked up from reading up on the 6ppc.
rwj
Gold $$ Contributor
Being new to rifle/bottle neck case reloading, turning necks would be one of the later steps in the learning process. Suggest starting with a chamber neck diameter that does not require neck turning. Some accomplished shooters are no longer turning necks.
If you already have a rifle/chambered barrel that does require turning necks, a good starting point would be a case neck wall thickness that results in 0.002/0.003” of diametral clearance on the loaded round. If the chamber neck diameter is 0.262”, subtract 0.002” (clearance) and 0.2433” (bullet diameter) then divide by 2 for your target case wall thickness (0.0083”). As I don’t know the wall thickness of unturned Lapua 220 Russian cases, I can’t cite how much needs to be removed. But removing 0.00818” seems excessive!
Welcome to BR shooting… enjoy the ride!
Edit to append this related thread…
Lapua 220 Russian brass neck thickness
Does anyone know the average neck thickness of unturned Lapua 220 Russian brass? I am trying to determine the average loaded round neck diameter using unturned 220 Russian brass. Thanks, EJ
forum.accurateshooter.com
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Ccrider
Gold $$ Contributor
Here is how you calculate:
Traditionally, for a .262 neck, most turned down to:
0086— .0086 + .0086 + .243= .2602, leaving .0018 clearance.
Jack Neary says “cut them thin to win:”
.0082– .0082 + .0082= .2594, leaving .0026 clearance.
I say turn to .0082. Try both and see what shoots best in your gun and then decide.
Either way, actually measure your finished round to make sure you have the clearance you think you have. Bullet thickness will impact the size of your finished round.
Traditionally, for a .262 neck, most turned down to:
0086— .0086 + .0086 + .243= .2602, leaving .0018 clearance.
Jack Neary says “cut them thin to win:”
.0082– .0082 + .0082= .2594, leaving .0026 clearance.
I say turn to .0082. Try both and see what shoots best in your gun and then decide.
Either way, actually measure your finished round to make sure you have the clearance you think you have. Bullet thickness will impact the size of your finished round.
For my .268 chamber neck diameter I turn necks to .265 loaded neck diameter which equals .011 neck thickness.
This gives .015 clearamce per side and total of .003 clearance. According to Jack Neary a long time Hall of Fame 6PPC Bench Rest shooter this is where he finds the proper bullet release and gas seal at ignition.
This gives .015 clearamce per side and total of .003 clearance. According to Jack Neary a long time Hall of Fame 6PPC Bench Rest shooter this is where he finds the proper bullet release and gas seal at ignition.
Hall of Fame and Southeasten Champion,Ed Watson,used .001" total neck clearance,per his article in "The Benchrest Shooters Primer" book. I use .0015" total clearance on my .268" Nk 6PPC's with no problems whatsoever.
Thank you Boyd Allen for your input. I always appreciate what you have to say.
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BoydAllen
Gold $$ Contributor
I used to run .0086 necks in my .262, but I know a couple of record holders and Hall of fame members and spoke with someone some time ago about what he found that Tony had gone to more recently, and that is why I am where I am. As I understand it, the advantage of more clearance mostly shows up at 200 yards. Some years ago, Gary Ocock told me that he wants to be at about two and three quarter thousandths.
3Ackleys
Gold $$ Contributor
I'm just curious as to what tool you are using to measure to the hundred thousandths?
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