What the right neck tension is? If a guy gets bushing dies and then different sizes, do you load up a few from each one and see what shoots the best with that bullet combo? Do you do this after you have your powder weight and your seathing depth figured out or before?
How do you know?
- Thread starter wisconsinteacher
- Start date
bozo699
Gold $$ Contributor
When I buy a bushing die I know about what I will need just by measuring the brass and a bullet, even closer if I seat a bullet in the brass to be used, I always buy bushing several up and down from what I want, I will use them at some point anyway for something, I now have boxes of them and rarely buy any anymore, once I find for sure through load developement I then buy a carbide if I can get one or a titanium nitride in the size needed and that is what I will use, I usually buy several of them at that time as they can vary sometimes as much a .0005 and that is good for really fine tuning, sometimes just turning the bushing over will gain you a little one way or the other.wisconsinteacher said:
Wayne.
GSPV
A failure to plan is a plan for failure.
You start with a recipe that is known to be about right, then you tune from there based on group size and other indicators.
My suggestion would be to get this book http://www.accurateshooter.com/book-dvd-reviews/tony-boyers-book-of-rifle-accuracy/
Tony is the best of the best in short range benchrest. There is a ton of info in there.
Mike Rattigan's book is another good source. Not as much detail in there about tuning, though.
In short, neck tension is the last thing that most of us vary, but we start with something that usually works.
I recommend that you become best friends with this page http://www.accurateshooter.com/cartridge-guides/6mmbr/ . Take this for what it's worth, but I recommend starting with non-VLD bullets. They are, for me at least, easier to tune. If you're going to do long range, the 107 SMK is a good place to start.
My suggestion would be to get this book http://www.accurateshooter.com/book-dvd-reviews/tony-boyers-book-of-rifle-accuracy/
Tony is the best of the best in short range benchrest. There is a ton of info in there.
Mike Rattigan's book is another good source. Not as much detail in there about tuning, though.
In short, neck tension is the last thing that most of us vary, but we start with something that usually works.
I recommend that you become best friends with this page http://www.accurateshooter.com/cartridge-guides/6mmbr/ . Take this for what it's worth, but I recommend starting with non-VLD bullets. They are, for me at least, easier to tune. If you're going to do long range, the 107 SMK is a good place to start.
My "system" (for lack of a better word) is this..
1) Do your standard load development changing ONLY the powder charge. find what shoots best in your gun WITHOUT changing any other perameter. My starting point is always .... xxx.x grains of powder and a 20 thou JAM!!! I ALWAYS start with the jam...... I do not change this during this stage of load development.
I do the next two steps in no paticular order. i do know that once you find the proper neck tention, it will NEVER CHANGE.....no mater what else you change/ try/ experement with....the proper neck tention will never change........
2) or 3) Take the load you found and try tinker with neck tention. If you have very thin necks you may need to try 4 or 5 different bushings. No turn necks usualy need only three bushings. Once you find it you find it!! I only need to shoot ONE five shot group with each bushing. You can figure it out in one range session.
3) or 2)...Seating depth......I load 5 of the load from step #1 and decrease the seating depth to ten in and ten off..... for a total of 15 shots. I try and stay away from the ZERO setting....any bullet runout will put you either into or out of the lands by the amount of the runout. A +.002 runout in the bullet, will make a huge difference with a ZERO starting point...... if you are at plus or minus 10 thou...or more....not so much. Again...one five shot group with each seating depth...it should be fairly obvious on the target!!!
Steps 2 and three need to be done at longer or long range. What you are trying to eliminate with these two steps is verticle dispersion. They WILL show up on target at 600 or 1k...not so much at 100 or 200.
Like I said, this is my system....right or wrong....and I take a look at ANY advice I get!!!
Good luck,
Tod
1) Do your standard load development changing ONLY the powder charge. find what shoots best in your gun WITHOUT changing any other perameter. My starting point is always .... xxx.x grains of powder and a 20 thou JAM!!! I ALWAYS start with the jam...... I do not change this during this stage of load development.
I do the next two steps in no paticular order. i do know that once you find the proper neck tention, it will NEVER CHANGE.....no mater what else you change/ try/ experement with....the proper neck tention will never change........
2) or 3) Take the load you found and try tinker with neck tention. If you have very thin necks you may need to try 4 or 5 different bushings. No turn necks usualy need only three bushings. Once you find it you find it!! I only need to shoot ONE five shot group with each bushing. You can figure it out in one range session.
3) or 2)...Seating depth......I load 5 of the load from step #1 and decrease the seating depth to ten in and ten off..... for a total of 15 shots. I try and stay away from the ZERO setting....any bullet runout will put you either into or out of the lands by the amount of the runout. A +.002 runout in the bullet, will make a huge difference with a ZERO starting point...... if you are at plus or minus 10 thou...or more....not so much. Again...one five shot group with each seating depth...it should be fairly obvious on the target!!!
Steps 2 and three need to be done at longer or long range. What you are trying to eliminate with these two steps is verticle dispersion. They WILL show up on target at 600 or 1k...not so much at 100 or 200.
Like I said, this is my system....right or wrong....and I take a look at ANY advice I get!!!
Good luck,
Tod
GSPV
A failure to plan is a plan for failure.
Two different ideas:
1. I always start with a powder charge, seating depth and neck tension that is known to work. I steal an amazing number of them from the cartridge-specific pages off the 6mmBR.com home page. That usually propels past "rough tuning" and right to "fine tuning". I'm different than most folks in that I twiddle with powder charge and seating depth looking for the load that prints just shy of the highest and will print fractionally lower if I increase the powder charge a hair or seat the bullet deeper into the lands. I'm looking to firm up a picture that says that the bullet is exiting the crown just shy of the highest point in its oscillation.
2. I find that when I am running a light neck tension, I have to go to slightly tighter bushings as the brass work hardens.
Take it for what it's worth.
1. I always start with a powder charge, seating depth and neck tension that is known to work. I steal an amazing number of them from the cartridge-specific pages off the 6mmBR.com home page. That usually propels past "rough tuning" and right to "fine tuning". I'm different than most folks in that I twiddle with powder charge and seating depth looking for the load that prints just shy of the highest and will print fractionally lower if I increase the powder charge a hair or seat the bullet deeper into the lands. I'm looking to firm up a picture that says that the bullet is exiting the crown just shy of the highest point in its oscillation.
2. I find that when I am running a light neck tension, I have to go to slightly tighter bushings as the brass work hardens.
Take it for what it's worth.
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