The advantage of the bushing die is being able to adjust the tension which varies over time, with usual optimal accuracy being afforded with a bushing .002" smaller than loaded round neck diameter, at least according to the BR crowd.
Bushing dies.. are they worth it!
- Thread starter schumy
- Start date
- Location
- rocky mountain house
the only way ANYONE can know how much neck tension is on a loaded round is seating with a wilson seater in a hydraulic arbor press such as the 21 century.
you can buy a torque wrench handle for your press to keep constant pressure on your collett dies.you can also order diffrent sizes of mandrels for collet dies in .001 increments to change neck tension. very simply the collett dies work well and as a competitive shooter i use them alot,but i also like bushing bump dies such as the Whidden,s. They are competitively priced and you get good dies every time.Unfortunately over many years i have had several substandard sets of redding dies and for their price i will go custom now.
Checked with a couple of the very top FClass shooters in Canada and some are using the new "21st Century hydraulic arbor press for seater" and using a variety of sizing dies including custom with .001-.002" tension. One top shooter used the fancy hydraulic seater but now simply uses "feel". Definitely interesting technology!
Chargerguy
CGN frequent flyer
This thread is perfect timing for me. I just started getting interested in upgrading to bushing dies.
Pretty bright statement whomever U. R
It is a difficult concept to grab and that is why some of us are using 1/2size neck bushings to fine tune the load, it seems overkill but how tight of groups do U want?
Good equipment can take U a long ways , especially if U fine tune it, I would rather have the most accurate gun I can when I go to the line knowing when I screw up it is all me,
Maybe I should not have revealed that as then everyone knows how lousy a shot I really am
Later. Jefferson
Hi Jefferson could you please expand on this are you talking the bushing itself (eg 262 bushing and next 261.5) or are you referring to neck sizing half the length of the neck. And if the former who is making these 1/2 sizes?
All the Best
Trevor
- Location
- rocky mountain house
He is referring to actual bushing sizes in .0005 increments.Its no secret that tuning your neck tension holds some of the key to lower velocity spreads among other things.the old adage of ".002 neck tension" should only be a starting point for tuning.
I'm new to rifle reloading (currently load only for pistol) but with a bushing die...because it sizes on the OD...would it not be an issue for proper tensioning the bullet, if you had brass with different wall thickness (either because on OEM specs, or from working the brass during reloads)
What is the solution here (if it's actually an issue). Would this require neck trimming...to ensure a consistent OD...to take full advantage of the bushing dies? I can see how a collet die may have some advantages.
Thanks in advance for any input...
What is the solution here (if it's actually an issue). Would this require neck trimming...to ensure a consistent OD...to take full advantage of the bushing dies? I can see how a collet die may have some advantages.
Thanks in advance for any input...
The value of my comments may be placed in the FWIW category but here are some observations on dies and sizing and the effects thereof. First off, I don't think anyone will argue that minimal sizing is not to be desired. Reduced working of the brass means the brass will last longer and work hardening will be reduced. With reduced work hardening comes better long-term uniformity. On the other hand, concentricity and alignment are better maintained if there is at least some contact with the case body. In addition, it is critical, is a bushing is used, that the bushing be postively aligned with the case body. A bushing which floats will yield eccentric case necks unless things go particularily well.
One has to use his/her immagination a bit to visualize the die at work and how things may go wrong because some of the results of a die behaving badly can be seem and understood. When a fired case is pushed up into a sizing die, there first contact will likely be at the mouth of the case unless the die is of the FL variety and the case is one with minimal body taper and a short neck (a description of many modern cartridges). As the case moves further into the die, the neck begins to be reduuced in diameter. At this stage, the body of the case may or may not be contacting the wall of the die. If it is not, the alignment of the neck can begin to be adversely affected. In other words, the neck might start to go crooked. This will continue until the body of the case contacts the body of the die. At this point the body will center up in the die and force the neck back into alignment; to a certain extent. Now, if the case neck was perfectly concentric with uniform thickness, the case mouth was perfectly square, the brass was uniform in grain structure, and the sizing was minimal, the neck could not be offset significantly and the body contact would have no effect; positive or negative.
The same sort of scenario occurs in a bushing die but here we can ensure that sizing is minimal so that helps. We can also ensure thay the body matches the case which is beneficial in some ways but not so much so in others. Since the die is perfectly matched to the brass (assuming this is a custom die matched to the rifle chamber) positive alignment of the case body will not occur until the case is fully seated in the die. The bushing , if it is aligned and captive, will size the neck as intended and, as the case hits home, the neck, if misaligned, will be forced back into alignment (sort of). If the bushing floats, the neck may or may not remain concentric and when the body is fully home, no re-alignment will take place since the bushing is simply pushed to the side.
Possibly the best system is one where the case is fully home before any sizing takes place and where both the body of the case and the neck sizing bushing are positively ahign by the die body or housing. I have made dies like this and they work very well but they are quite difficult to make since tolerances must be held very closely and this means the die body, the sleeve which accepts and guides the case and the neck sizing bushing must all fit together with minimal clearance yet move freely. When all is said and done you will have a very expensive die which will produce a sized case which is every bit as straight as that produced by a typical FL sizing die! The only difference is that you will have worked the brass to a minmal extent.
I frequently make bushing -type dies simply because factory dies do size the neck and body of the case too much. This is especially so for certain cartridges. For instance, I recently barreled up a 30/30 Winchester HV rifle. Now, factory dies for the 30/30 size that neck like there iks no tomorrow and then expand it back up to almost accept a bullet. The sized neck is eccentric to the body and when the bullet is seated, it is likely to eccentric to the neck; hardly a recipe for precision. So the answer was to make a bushing die to size the neck minimally and a seater which positively aligns bullet and case. Although most cartridges don't suffer from quite the lack of precision in dies quite as much as the 30/30, there is still a lot of compromise in dimensions since, in the view of the manufacturers, a die which works poorly is still a better tool than one which doesn't work at all.
When busings are chosen, the bushing should size the neck to where it is approximately .002 inches smaller than the same neck with a bullet seated. If one is shooting moly coated bullets, the amount of sizing should be increased to .003 smaller. Please note that this refers to the diameter of the sized neck, NOT necessarily the diameter of the bushing. Brass will spring back to a greater or lesser extent depending on the hardness of the brass. This explains the recent resurgence of the popularity of annealing brass to achieve greater consistency. When one encounters variations in the required seating pressure, it is variations in brass hardness which is the usual culprit.
I could go on but even I am getting bored with it and can't imagine the effect this must be having on an innocent reader! I will close with this bit of advice: If your rifle is shooting 1 1/2 moa, you can futz around with your sizing die 'til the cows come home (though what cows might have to do with it, I can't say) and you will be wasting your time. Unless the introduced error is gross a better sizer ain't gonna fix a bad shooting rifle.
One has to use his/her immagination a bit to visualize the die at work and how things may go wrong because some of the results of a die behaving badly can be seem and understood. When a fired case is pushed up into a sizing die, there first contact will likely be at the mouth of the case unless the die is of the FL variety and the case is one with minimal body taper and a short neck (a description of many modern cartridges). As the case moves further into the die, the neck begins to be reduuced in diameter. At this stage, the body of the case may or may not be contacting the wall of the die. If it is not, the alignment of the neck can begin to be adversely affected. In other words, the neck might start to go crooked. This will continue until the body of the case contacts the body of the die. At this point the body will center up in the die and force the neck back into alignment; to a certain extent. Now, if the case neck was perfectly concentric with uniform thickness, the case mouth was perfectly square, the brass was uniform in grain structure, and the sizing was minimal, the neck could not be offset significantly and the body contact would have no effect; positive or negative.
The same sort of scenario occurs in a bushing die but here we can ensure that sizing is minimal so that helps. We can also ensure thay the body matches the case which is beneficial in some ways but not so much so in others. Since the die is perfectly matched to the brass (assuming this is a custom die matched to the rifle chamber) positive alignment of the case body will not occur until the case is fully seated in the die. The bushing , if it is aligned and captive, will size the neck as intended and, as the case hits home, the neck, if misaligned, will be forced back into alignment (sort of). If the bushing floats, the neck may or may not remain concentric and when the body is fully home, no re-alignment will take place since the bushing is simply pushed to the side.
Possibly the best system is one where the case is fully home before any sizing takes place and where both the body of the case and the neck sizing bushing are positively ahign by the die body or housing. I have made dies like this and they work very well but they are quite difficult to make since tolerances must be held very closely and this means the die body, the sleeve which accepts and guides the case and the neck sizing bushing must all fit together with minimal clearance yet move freely. When all is said and done you will have a very expensive die which will produce a sized case which is every bit as straight as that produced by a typical FL sizing die! The only difference is that you will have worked the brass to a minmal extent.
I frequently make bushing -type dies simply because factory dies do size the neck and body of the case too much. This is especially so for certain cartridges. For instance, I recently barreled up a 30/30 Winchester HV rifle. Now, factory dies for the 30/30 size that neck like there iks no tomorrow and then expand it back up to almost accept a bullet. The sized neck is eccentric to the body and when the bullet is seated, it is likely to eccentric to the neck; hardly a recipe for precision. So the answer was to make a bushing die to size the neck minimally and a seater which positively aligns bullet and case. Although most cartridges don't suffer from quite the lack of precision in dies quite as much as the 30/30, there is still a lot of compromise in dimensions since, in the view of the manufacturers, a die which works poorly is still a better tool than one which doesn't work at all.
When busings are chosen, the bushing should size the neck to where it is approximately .002 inches smaller than the same neck with a bullet seated. If one is shooting moly coated bullets, the amount of sizing should be increased to .003 smaller. Please note that this refers to the diameter of the sized neck, NOT necessarily the diameter of the bushing. Brass will spring back to a greater or lesser extent depending on the hardness of the brass. This explains the recent resurgence of the popularity of annealing brass to achieve greater consistency. When one encounters variations in the required seating pressure, it is variations in brass hardness which is the usual culprit.
I could go on but even I am getting bored with it and can't imagine the effect this must be having on an innocent reader! I will close with this bit of advice: If your rifle is shooting 1 1/2 moa, you can futz around with your sizing die 'til the cows come home (though what cows might have to do with it, I can't say) and you will be wasting your time. Unless the introduced error is gross a better sizer ain't gonna fix a bad shooting rifle.
Thanks for the request Peter
I hesitated to respond to this topic because I am in the minority. I use a Lee Collet die extensively in conjunction with a custom bushing die. I see the benefits of the Lee die as an F class shooter outweighing the use of the bushing dies alone.
What I am looking to achieve is consistent neck tension with minimal or zero irregular neck pressure. How can I achieve that with a bushing die that pushes the irregularities to the inside of the neck.
How do I get consistent neck tensions
By squeezing the case using a bushing into open space or
By using the Lee die and compressing the neck around a specific dia mandrel.
By using the lee die I keep the irregularities to the outside and get more consistent tension instead of having the irregularities pushed inside (bushing) when seating a bullet.
**You can eliminate almost 100% of the neck dia irregularities by turning necks. I need a lathe to get rid of 100%.
The Lee die I use has a .306 mandrel I have other mandrels from lee including a .304(each additional mandrel from Lee cost $5.00+ shipping)
I always start with the .306 and adjust accordingly if that doesn’t work I will switch to the .304 and see if the initial tension tightens my group and lowers my numbers. Believe in your groups not what the chrony tells you.
One other trick I do is to turn the brass 90 degrees and run it through the lee die again.
My process of incorporating the FL bushing die is:
FL die with large bushing I use a .341 bushing: Newlon die blank with a sizing reamer spec'd to my finishing reamer.
followed by the Lee die to finish to the desired neck tension. This 2nd step may be days/weeks from the initial FL sizing. I run all the cases through each individual operation to avoid missing one step.
I run the Lee die mins or hours before i start loading rounds
before 1st firing... expand followed by the Lee collet die (this first firing is to form the case to the chamber and give me an idea of where to set my full length bushing die)
Factory brass typically falls closer to min SAAMI dimensions and most off the shelf rifles and my custom reamer have larger then min SAAMI dimensions. To get the proper length and width I use the first firing to get the brass close to chamber size. Some guys do 2 firings before they every gets used in a match.
I will load one case 3x in a row to fined my max case dimensions and have a reference to compare the 1st firing to 3x and adjust my FL die accordingly. Max dia. is reached first (in some cases after the first firing) followed by the length.
I really want to try the 21st century hydraulic press and Wilson dies. I have been offered the opportunity to run a blind test to compare numbers between me and him. He hasn't committed to the press at this point and i haven't tested it. I have a new barrel that has 30 rds through it and i haven't found my optimal load and seating depth using my method to provide a baseline, it would be a waste to the hydraulic press at this state.
All the Best
Trevor
P.S.
280 Ackley
I have never seen a bushing in 1/2 sizes. a look at grafs or Hirsch site show only full sizes.. can you direct us to where they are listed?
I hesitated to respond to this topic because I am in the minority. I use a Lee Collet die extensively in conjunction with a custom bushing die. I see the benefits of the Lee die as an F class shooter outweighing the use of the bushing dies alone.
What I am looking to achieve is consistent neck tension with minimal or zero irregular neck pressure. How can I achieve that with a bushing die that pushes the irregularities to the inside of the neck.
How do I get consistent neck tensions
By squeezing the case using a bushing into open space or
By using the Lee die and compressing the neck around a specific dia mandrel.
By using the lee die I keep the irregularities to the outside and get more consistent tension instead of having the irregularities pushed inside (bushing) when seating a bullet.
**You can eliminate almost 100% of the neck dia irregularities by turning necks. I need a lathe to get rid of 100%.
The Lee die I use has a .306 mandrel I have other mandrels from lee including a .304(each additional mandrel from Lee cost $5.00+ shipping)
I always start with the .306 and adjust accordingly if that doesn’t work I will switch to the .304 and see if the initial tension tightens my group and lowers my numbers. Believe in your groups not what the chrony tells you.
One other trick I do is to turn the brass 90 degrees and run it through the lee die again.
My process of incorporating the FL bushing die is:
FL die with large bushing I use a .341 bushing: Newlon die blank with a sizing reamer spec'd to my finishing reamer.
followed by the Lee die to finish to the desired neck tension. This 2nd step may be days/weeks from the initial FL sizing. I run all the cases through each individual operation to avoid missing one step.
I run the Lee die mins or hours before i start loading rounds
before 1st firing... expand followed by the Lee collet die (this first firing is to form the case to the chamber and give me an idea of where to set my full length bushing die)
Factory brass typically falls closer to min SAAMI dimensions and most off the shelf rifles and my custom reamer have larger then min SAAMI dimensions. To get the proper length and width I use the first firing to get the brass close to chamber size. Some guys do 2 firings before they every gets used in a match.
I will load one case 3x in a row to fined my max case dimensions and have a reference to compare the 1st firing to 3x and adjust my FL die accordingly. Max dia. is reached first (in some cases after the first firing) followed by the length.
I really want to try the 21st century hydraulic press and Wilson dies. I have been offered the opportunity to run a blind test to compare numbers between me and him. He hasn't committed to the press at this point and i haven't tested it. I have a new barrel that has 30 rds through it and i haven't found my optimal load and seating depth using my method to provide a baseline, it would be a waste to the hydraulic press at this state.
All the Best
Trevor
P.S.
280 Ackley
I have never seen a bushing in 1/2 sizes. a look at grafs or Hirsch site show only full sizes.. can you direct us to where they are listed?
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I never did get into neck sizing, I decided it was not necessary to make accurate ammo. I bought some nice FL sizers (Forster and Redding) and Redding comp seater dies. I resize my cases one thou smaller than the chamber and run my brass lots through 10 firings before I get rid of them. Simple and easy, I enjoy getting out there shooting instead of involved reloading.
That's why I use the Lee neck sizer, no lube to wipe on or off. I hate removing lube before seating/loading.
- Location
- rocky mountain house
Trevor, you are certainly not a minority when it comes to the use of collet dies.You,like alot of the rest of us,have figured out how many problems the collet dies solve in the quest to build perfect ammunition.As far as the half size bushings it was an idea i had last year.I have approached a bushing company asking if they would build bushings in 1/2 thou sizes and they are getting back to me on it.I dont know where jefferson got his .5 bushings from.In my mind this should be easy to do for the bushing companies;as easy as it is for companies to build reamer bushings in .0002 increments.
If you are going to shoot the canadians this year look me up and we can sit and talk about this stuff!i never get tired of learning;the quest for perfection should never be limited to what shooterX or shooterY are doing at a particular year because i guarantee if they want to stay at the top of the field they are constantly improving also.
cheers, Bob G.
100 Yards. That was nearly 5 years ago. The rifle now has over 4,300 rounds through it.
2 years ago at a precision rifle clinic in Petawawa it shot 50.9V at 500M
It no longer shoots that well. It's time to rebarrel it.
I contacted Redding many years back to request expander mandrels in .0002" increments to use in conjunction with the bushing dies to fine tune neck tension from the inside where it counts most.
They didn't even get it and I dropped the point but stand firm that it would be a solid advancement over the bushing alone.
Getting neck tension just right with bushing dies is a bit of a trick and here's why...
Case wall thickness varies both at different points of measurement around the same neck and from one case to the next.
Ok you can just neck turn right? Yes but then you get into the next level of problems associated with the various hardness of the brass proportionally affecting spring back.
In this regard you will find you only really know how much spring back there is after you resize each individual neck.
If you use the same bushing for all cases in a lot, you will need the seating pressure scale, as mentioned above, to discern a tight one from a light one,,, unless you get a little creative and here's how...
If you pay close attention to the case when you resize the necks you will notice that neck sizing induces a taper to the neck... the mouth of the case is smaller than the diameter closer to the shoulder.
The more you reduce the neck diameter... the greater the taper that gets induced... and the less control you have over consistent neck tension.
If you have a tight neck chamber then you're resizing only a thou or two so you wont have much taper, but if you have a well cleared neck and are reducing 0.010-0.012" then you are inducing serious taper... if you resize in a single step.
Here's where it gets interesting...
If you resize the cases 0.002 too large to hold a bullet and then incrementally resize by one bushing smaller you will eventually find that some of the cases will hold a bullet and some will not...
At this point you separate the cases that hold a test bullet and move the loose cases to another container. Assuming all your necks are turned at this point, these first tight cases are the ones with the softest necks. You know this because they had the least spring back.
Now you move to the next bushing smaller and resize the necks of the cases that are still too loose to hold a bullet
At this point some of the cases will hold a bullet and you put those aside.
Just repeat until all cases will hold a bullet and make sure you know which cases were sized with which bushing.
............................................
Now to test the tapered necks I mentioned above....
You will find that by the time you get all the cases resized to hold a bullet using this incremental method, you will be using at least 0.001" or 0.002" smaller bushing than you would have been using if you resized all the cases in a single step. The difference is the taper caused by neck resizing.
This is the best method I know of to precisely control neck tension and reduce SDs.
..........................................
As for controlling concentricity between the case body and neck... you cannot reliably control this at the reloading stage... here's why...
Body to neck runnout is a direct byproduct of the amount of neck reduction you are performing.
If you are reducing the neck diameter by 0.012 then it is theoretically possible to have as much as 0.012" of runout on a worst case scenario...
On the other hand, if you are only reducing the neck diameter by 0.002" then the maximum possible runout you can induce is 0.002"
Therefore the best way to ensure that your necks are concentric is to run a tight neck chamber with minimal neck clearance.
If you have a sloppy neck clearance you can never get better concentricity than a guy with a tight neck chamber regardless of the dies you size with. Its a statistical impossibility.
They didn't even get it and I dropped the point but stand firm that it would be a solid advancement over the bushing alone.
Getting neck tension just right with bushing dies is a bit of a trick and here's why...
Case wall thickness varies both at different points of measurement around the same neck and from one case to the next.
Ok you can just neck turn right? Yes but then you get into the next level of problems associated with the various hardness of the brass proportionally affecting spring back.
In this regard you will find you only really know how much spring back there is after you resize each individual neck.
If you use the same bushing for all cases in a lot, you will need the seating pressure scale, as mentioned above, to discern a tight one from a light one,,, unless you get a little creative and here's how...
If you pay close attention to the case when you resize the necks you will notice that neck sizing induces a taper to the neck... the mouth of the case is smaller than the diameter closer to the shoulder.
The more you reduce the neck diameter... the greater the taper that gets induced... and the less control you have over consistent neck tension.
If you have a tight neck chamber then you're resizing only a thou or two so you wont have much taper, but if you have a well cleared neck and are reducing 0.010-0.012" then you are inducing serious taper... if you resize in a single step.
Here's where it gets interesting...
If you resize the cases 0.002 too large to hold a bullet and then incrementally resize by one bushing smaller you will eventually find that some of the cases will hold a bullet and some will not...
At this point you separate the cases that hold a test bullet and move the loose cases to another container. Assuming all your necks are turned at this point, these first tight cases are the ones with the softest necks. You know this because they had the least spring back.
Now you move to the next bushing smaller and resize the necks of the cases that are still too loose to hold a bullet
At this point some of the cases will hold a bullet and you put those aside.
Just repeat until all cases will hold a bullet and make sure you know which cases were sized with which bushing.
............................................
Now to test the tapered necks I mentioned above....
You will find that by the time you get all the cases resized to hold a bullet using this incremental method, you will be using at least 0.001" or 0.002" smaller bushing than you would have been using if you resized all the cases in a single step. The difference is the taper caused by neck resizing.
This is the best method I know of to precisely control neck tension and reduce SDs.
..........................................
As for controlling concentricity between the case body and neck... you cannot reliably control this at the reloading stage... here's why...
Body to neck runnout is a direct byproduct of the amount of neck reduction you are performing.
If you are reducing the neck diameter by 0.012 then it is theoretically possible to have as much as 0.012" of runout on a worst case scenario...
On the other hand, if you are only reducing the neck diameter by 0.002" then the maximum possible runout you can induce is 0.002"
Therefore the best way to ensure that your necks are concentric is to run a tight neck chamber with minimal neck clearance.
If you have a sloppy neck clearance you can never get better concentricity than a guy with a tight neck chamber regardless of the dies you size with. Its a statistical impossibility.
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