Results from body die sizing - is this expected? - with pics

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RonR

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Hi All,

My first experience with body die sizing has lead to more questions to results I am experiencing, and am putting this out there to see if others can share experiences or insight.

Givens
- Relatively new reloader. Have neck sized only. No full length sizing experience…so body die is just as new and never done it before. Patience for any of my ignorance is requested. 
- Body sizing to bring back the cartridge for easier chambering. I had to pull some loaded rounds that were test fit prior to hunting last year…and I am glad I did that.
- 7mm-08, Savage
- Loading for accurate hunting rounds, no competition…just bragging rights with the crew.;)
- Lee single stage press, Redding body die
- Using Hornady comparator set to measure the differences in shoulder throughout resizing. Ultimately the “too tight” fit cartridges in the rifles chamber were measured as reference to another value .002 to .003 less in length.

At first just turning the die for contact and increasing 180 degrees a crack, it seemed like forever until there was any measurable difference in shoulder position. It seemed as though the body of the cartridge below the shoulder was getting sized and the shoulder position stayed as is. Near to the end of die depth to produce shoulder set back, in advance of any noticeable shoulder set back, the cartridges increased in shoulder length by .002. <<< I understand the growth, just didn’t anticipate it. Then there was a different feel on the press like a second stage of pressure/release and finally there was shoulder bump back.

Pictures as reference. 3 on the left body sized. 2 on the right not sized.

1. What am I experiencing here… is this normal to have this change in cartridge body below the shoulder prior to shoulder bump back?

2. My comprehension of shoulder bump using the body die was that it was just going to tap back the shoulder and leave the rest of the cartridge as is. Please advise if expectations are incorrect. Without considering the neck, is this result not approaching full length resizing?

3. Redding competition shell holders…is this a possible solution to get the shoulder bump without so much of the rest of the body getting resized? Or is my math/understanding of what's meant to occur all wrong?

Thanks Nutz in advance
Regards
Ron

e5prbc.jpg


29pxhxc.jpg
 
RonR said:
Hi All,

My first experience with body die sizing has lead to more questions to results I am experiencing, and am putting this out there to see if others can share experiences or insight.

Givens
- Relatively new reloader. Have neck sized only. No full length sizing experience…so body die is just as new and never done it before. Patience for any of my ignorance is requested. 
- Body sizing to bring back the cartridge for easier chambering. I had to pull some loaded rounds that were test fit prior to hunting last year…and I am glad I did that.
- 7mm-08, Savage
- Loading for accurate hunting rounds, no competition…just bragging rights with the crew.;)
- Lee single stage press, Redding body die
- Using Hornady comparator set to measure the differences in shoulder throughout resizing. Ultimately the “too tight” fit cartridges in the rifles chamber were measured as reference to another value .002 to .003 less in length.

At first just turning the die for contact and increasing 180 degrees a crack, it seemed like forever until there was any measurable difference in shoulder position. It seemed as though the body of the cartridge below the shoulder was getting sized and the shoulder position stayed as is. Near to the end of die depth to produce shoulder set back, in advance of any noticeable shoulder set back, the cartridges increased in shoulder length by .002. <<< I understand the growth, just didn’t anticipate it. Then there was a different feel on the press like a second stage of pressure/release and finally there was shoulder bump back.

Pictures as reference. 3 on the left body sized. 2 on the right not sized.

1. What am I experiencing here… is this normal to have this change in cartridge body below the shoulder prior to shoulder bump back?

2. My comprehension of shoulder bump using the body die was that it was just going to tap back the shoulder and leave the rest of the cartridge as is. Please advise if expectations are incorrect. Without considering the neck, is this result not approaching full length resizing?

3. Redding competition shell holders…is this a possible solution to get the shoulder bump without so much of the rest of the body getting resized? Or is my math/understanding of what's meant to occur all wrong?

Thanks Nutz in advance
Regards
Ron

e5prbc.jpg


29pxhxc.jpg
Click to expand...

1) Yes.

2) Assumptions were incorrect. A Redding body die is a FL die with no neck section.

3) The Redding competition shellholders are an easy and accurate way of controlling how far the case is pushed into the die. That's it, that's all. Having said that; what a great way of doing that one thing.
 
I did my first shoulder bumping just a couple months ago. I too took forever to get the setting right too....and in the end yodave taught me that RCBS shell holders suck, and yes, getting Redding ones helps.
 
Below is my Forster bushing bump .223 die, it will just size the neck or if lowered a few thousandths it will also bump the shoulder. It comes with three bushings "BUT" my standard Forster full length benchrest dies with the high mounted floating expander produces cases with less neck runout.

bump_zpsc21e51f6.jpg


Normally I associate a body die like you have that sizes everything but the neck with shooters who are using a Lee collet die for the case neck.

I prefer to full length resize and the Forster full length benchrest dies produce the least amount of bullet runout along with their benchrest seating die.

Below the Forster full length die with the high mounted floating expander. The neck of the case is held and centered in the die when the expander enters the case neck. With this type spindle and expander assembly it can not pull your necks off center and induce neck runout.

Sizer_Die_011_zpst2zm6m7y.gif
 
Thanks all,

GGG, good to know someone else is going through similar operations. For a while with no responses on this thread I was wondering if it was something I said or garlic breath from last nights supper. :d (I am still interested in seeing the results from the neck turning operations. I am on to that next after this.)

Dogleg, thanks for the nice clear response. I am struggling with the term bump and how it’s used in this instance because of the results, but I am getting over it and I think I understand. …Regarding 2) since this is the change to my cartridges I can see why there is the fl sizing train of thought and another being neck sizing/bump. One operation with options for fl die style and method with good options for adjustments and customization to meet specific tailored needs, and this one neck sizing/bump separate operations with infinite adjustments. Regarding 3) if I understand the process correctly, in my particular case competition shell holders do not offer anything. Competition shell holders are for those that use a f/l die that need to have less cartridge insertion (less shoulder bump) into the dies while having the full range of other resizing operations?

Big Ed, thanks for the response on this post and others. (I read your posts and Jerry's closely.) Is it the Co-Ax washer that provides the floating component for alignment of the spindle? Does the die body also float or self center so to speak? Just myself I have wondered about cartridge alignment/initial contact being in two places, on the ball and the other the de-capping pin. Do those ever oppose each other or create opportunity for misalignment when working down into the case? <<<pardon any ignorance on my part…it’s just what I am seeing.

Regards
Ron
 
Anything you are feeling stupid about, I've done, and likely worse.

If you haven't bought turning stuff, hold off. I see you have the 3 wheat sheafs in your avatar.....and I know a guy that has a full setup.

I'd say buy an annealer before turning stuff, or if you're handy build and induction one like others are doing in another thread on here....

MY F CLASS RIFLE ARRIVED TODAY!!! Now I can get a starting seating depth and start my powder choosin'!!!! Sorry for the noise neighbors.....
 
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1. What am I experiencing here… is this normal to have this change in cartridge body below the shoulder prior to shoulder bump back? No.... you are sizing the top part of the case body because the chamber is near the max allowable dimensions

2. My comprehension of shoulder bump using the body die was that it was just going to tap back the shoulder and leave the rest of the cartridge as is. Please advise if expectations are incorrect. Without considering the neck, is this result not approaching full length resizing? Correct, the body die is designed to be min spec headspace. Max spec body and base dimension... a bit closer to "standard" in the shoulder area. The reason the body die is acting like a FL die is because the chamber dimensions are approaching the max allowed by SAAMI

3. Redding competition shell holders…is this a possible solution to get the shoulder bump without so much of the rest of the body getting resized? Or is my math/understanding of what's meant to occur all wrong? The shellholders will not help with your situation as the dimension of the case after firing is at max spec in the shoulder area. The only thing the SH can help is easy adjustments of the headspace dimension while leaving the die in the same position in the press. Sizing a bit in the shoulder area really isn't going to hurt and will ensure proper chambering if things get wet/dirty.

There is an assumption that sizing dies are made to a specific dimension... they aren't. They fit into various categories and have the lattitude to manipulate various parts of the case within the sizing range offered by SAAMI. Before you ask, YES FL sizing dies can and will vary and in how and where they size.

Think of dies like Shoes..... although they may have the same SIZE... they do not need to have the same FIT

So you need to choose the dies that best suit the chamber and application you want/need.

many accuracy minded reloaders use the Body die because it allows the case to swell for a precise fit in the chamber and align better with the bore. It is the no brainer approach as a chamber under max spec is not touched much if any.

And it is the back half of the case that aligns the bullet with the bore.. Not the case shoulder.

Jerry
 
it's a body bump die, it does 2 things, it bumps the shoulder back, like you set out to do, second it sizes the web and body of the case. As your case was inserted into the die the body of the case was forced down in diameter, the metal had to go somewhere right, thats why the case grew in length when you measured the shoulder to base measurement, once the body of the case was sized to spec the die began to push the shoulder back, which again you saw the results of.

Redding makes 2 different body bump dies depending on the cartridge, regular die and small base die. In the world of the 6mmbr and a savage rifle using the regular shoulder bump die, as the shoulder is pushed back it causes the body of the case to swell and the case will no longer chamber, to combat this new found issue one has to use the small base body bump die and work both areas of the brass in order to get them to chamber with minimal bolt drag when closing the bolt on a bumped case.

Hats off to you for knowing what to measure and what to watch for, and for reaching out when things got weird, but what you experienced is totally normal, I use a small amount of sizing wax on the lower 3rd of my cases when I body bump them, I also make a mark on the top of the die and turn it down 1/12th of a turn at a time while measuring, to achieve that I turn the mark from 2 o'clock to 3 o'clock and then measure the brass and also try it in the chamber, because who says my chamber is minimum spec right, when the hold handle works freely I call it good and lock the die down, on a hunting rifle I might go one more hour on my clock and give me a bit more fit in the chamber.
 
RonR said:
Big Ed, thanks for the response on this post and others. (I read your posts and Jerry's closely.) Is it the Co-Ax washer that provides the floating component for alignment of the spindle? Does the die body also float or self center so to speak? Just myself I have wondered about cartridge alignment/initial contact being in two places, on the ball and the other the de-capping pin. Do those ever oppose each other or create opportunity for misalignment when working down into the case? <<<pardon any ignorance on my part…it’s just what I am seeing.

Regards
Ron
Click to expand...

Ron

1. The thick rubber washer (W-10) allows the spindle to float and self center with the neck of the die.
2. You can make any resizing die float and self center in the press by placing a rubber o-ring under the dies lock nut.
3. Any low mounted expander can pull your case necks off center, and the Forster expander works better than any other type die.
4. When resizing with a full length die with the expander removed the resized case should have little to no neck runout. Meaning the case is as straight as its going to get, and the expander is the first cause of neck runout.
5. Many neck sizing dies do not fully support the case body and this will cause the neck to be sized off center with the body of the case.
6. My Redding full length dies with the low mounted oblong expander will pull the necks off center very easily. But if equipped with a round floating carbide expander produces much less neck runout. But the Forster full length die produces the least neck runout of any type die I own.
7. The Forster bushing bump die produces more neck runout than the standard full length Forster die.
8. Mystic Precision was spot on when he compared dies to shoe sizes and how they fit. So remember we live in a plus and minus manufacturing world and no two chambers and dies are the same.

O-Rings on Dies May Reduce Run-Out
http://www.accurateshooter.com/technical-articles/reloading/o-rings-on-dies-may-reduce-run-out/

Below a RCBS full length resizing die equipped with a Forster expander and spindle assembly and a Lee lock ring with a rubber o-ring.

IMG_2140_zpsea657d9e.jpg


o-ring001_zps094cec91.jpg
 
GGG, the encouragement is appreciated. I’m in Saskatoon. I did purchase neck turning equipment but I haven’t yet put it to use. I hope to get it working at the end of this month…commitments pending…however one never knows what happens between now and when I actually get to it.

P51 much appreciated. I am going to digest more to make sure I understand. I have seen your other posts on concentricity with equipment and experience to substantiate and I appreciate that perhaps more than most.

Jerry you have summed up my fears after contemplating the responses and my results. My chamber is big and I will be working the brass like fl sizing. Kind of a downer but it is a hunting rig and I am enjoying the science and challenge to make the most of what I have. I’ll just have to purchase more brass in the future! The shoe analogy resonates on this end. I get that part. In this case I don’t think there is a solution without a custom die…and at that rate I’d like to spend my money elsewhere like a barrel and or stock/bedding. I still think I am winning with the body die but the range will cut to the chase.

(This reminds me of my old 72 chevy. As a teenager I was wrenching every weekend to keep it running but I learned a lot and appreciated the sweat to make it go better than most.<<< had to share that. I’m not too proud to say that I am still working on my driving skills at the range, so to speak. Always room for improvement. People can make fast cars but can they drive? )

Thanks for weighing in Yodave. You have explained perfectly what I have experienced. I really had to think about what was going on when the shoulder length grew and then with the smallest adjustment, voila the shoulder set back occurred. I could almost feel the moment when the shoulder got bumped back. After bumping a hundred cases tonight I can tell by the feel on the press which ones fall into spec and which ones have been culled to the WTF pile for analysis at a later date. After this chapter of body sizing I have got a whole new line of questioning on brass. Stuff like hardness and consistency of metallurgic composition between cartridge manufacturers (get what you pay for) but it’s a topic for a new thread and I want to see if I can make correlations on my own first. I only know Federal brass from factory round that I’ve kept and PRVI from Jerry so there’s much more to try and compare.

Thanks all for your time.

Regards
Ron
 
When seeking to bump a shoulder back a thou or two by adjusting the die, a little thought and a little math can illustrate the problem. First there is a wild amount of flex in a press, and the amount it flexes varies with sizing effort. Sizing effort varies with brass hardness and the amount of sizing needed, both of which vary with the amount of times it has been fired, how hot the loads were and the brand and lot of the cases. That die that seems so solidly mounted might as well be hanging on a rope.

Next consider that on a 14 thread per inch die a full turn is right around 71 thousandths, an hour on a clock is about 7 and a second a bit over 1. That's pretty precise die twisting, but since the die is a moving target it becomes an excercise in futility anyway. Sort of like measuring with a micrometer then cutting with a chainsaw. Make that cutting a moving object with a chainsaw. That's where a set of Competition shell holders can help. First they eliminate the variability of press flex, and second they eliminate the variability of twist adjustment. The WTF pile will get smaller.:)
 
Dogleg said:
When seeking to bump a shoulder back a thou or two by adjusting the die, a little thought and a little math can illustrate the problem. First there is a wild amount of flex in a press, and the amount it flexes varies with sizing effort. Sizing effort varies with brass hardness and the amount of sizing needed, both of which vary with the amount of times it has been fired, how hot the loads were and the brand and lot of the cases. That die that seems so solidly mounted might as well be hanging on a rope.
Click to expand...

Great explanation. Wow…for me and where I’m at WRT reloading that’s prophetic. The press did flex but I just don’t have a comparative to know how much. There was a considerable range of effort between cases. There was an expected correlation between the 3x fired vs the factory fired in terms of stiffness and contribution to WTF pile but it was not absolute which is also explainable and as you outlined. Within reason, I would like to develop some measure of predictability with the brass I have and the modest loads used for when the brass needs annealing. I have got a lot to learn and test.

Dogleg said:
Next consider that on a 14 thread per inch die a full turn is right around 71 thousandths, an hour on a clock is about 7 and a second a bit over 1. That's pretty precise die twisting, but since the die is a moving target it becomes an excercise in futility anyway. Sort of like measuring with a micrometer then cutting with a chainsaw. Make that cutting a moving object with a chainsaw. That's where a set of Competition shell holders can help. First they eliminate the variability of press flex, and second they eliminate the variability of twist adjustment. The WTF pile will get smaller.:)
Click to expand...

Geez, I think you just explained something else to me. Using the clock analogy, there was about 5 min of rotation where there was no effect on shoulder bump. It was either no effect or 2 to 3 thou of bump. I couldn’t get it to adjust any less. Is this the moving target you speak of?

I’m not sure I get how the competition shell holders help but I’ll take a crack at it…for this situation and set up I have (die, press, brass hardness state, setup) by adjusting the distance between case head and die there can be a sweet spot to compensate/correct what I am experiencing with the no adjust point in die rotation?

Your time and explanation are appreciated Dogleg.

Regards
Ron
P.s. The expertise and wisdom of some of you Nutz is remarkable.
 
I'll take another crack at explaining how the competition shell-holders work. Do you know how the instructions that come with a FL die usually have you crank the die down to contact the shell-holder then another quarter turn or so? That little extra compensates for the flex in the press and linkage and keeps the shellholder solidly against the bottom of the die no matter how much resistance the brass gives. In some cases that might size the brass more than enough but at least they are all more or less the same. When you back the die out so there is an air gap between the die and the shell-holder the amount that the shoulder gets bumped is directly related to how much effort was needed to size the case. A hard piece of brass, or more swollen case or even less lube will flex the press more and size the case less. When it gets sized less, the base to shoulder measurement increases. It would miraculous that any are the same length, except that there are so many cases getting sized.

The Competition shell-holders get away from that variation by being set exactly the same as the standard instructions for most dies. They bottom hard, and then some. Flex in the press is compensated for. Its still there but doesn't matter much because the case is going to going to get shoved in until the shellholder hits. Instead of trying to adjust the die, you get a set of 6 shell-holders that with different lengths. There is a standard, .002, .004 and so on up to .010" over. When you need to FL size your cases, try the .010" and see how it chambers. If that isn't enough, try the .008 and so on until the desired effort on the bolt handle is achieved. Some like just a bit of resistance when lowering the bolt, and some will go one past. Once the proper shellholder is found, write the magic number down on the die box. You can even use the same die on multiple rifles without adjusting, just by noting which shellholder gets used with which rifle.

I've moved away from collet and neck dies and back to FL sizing for most of my rifles. If a new rifle shows up I'll just start with new brass and the .010 shellholder. I'll use it and let the cases grow until there is more chambering effort than I want, then go through the series for the perfect fit. Then it gets written down too.
 
Below is a photo of the Redding Competition shell holders, you get five shell holders a (plus) +.002, +.004. +.006, +.008 and +.010

reddingshellholders_zpsa84fa472.jpg


Normally a standard shell holder pictured below has a X dimension of .125. The competition shell holders would be .127, .129, .131, .133, .135 and the deck height where the case rests are lower. Meaning the competition shell holders do not push the case as far into the die as the standard shell holder. And as stated above the die still makes hard contact with the top of the shell holder removing any slop in the press.

techtalkshellhldr_zpsunhebtoy.jpg


Below I use the (plus) +.004 competition shell holder on the left to give me .003 shoulder bump on my .223/5.56 cases for my AR15 rifles. If the standard shell on the right had been used and set up per the dies instructions the case shoulder would have been bumped back .007.

shellholders_zps0f9bb695.jpg


I'm still using my Rockchucker I bought in 1973 and the competition shell holders remove any slop in the well used press.
 
bigedp51 said:
Below is a photo of the Redding Competition shell holders, you get five shell holders a (plus) +.002, +.004. +.006, +.008 and +.010

reddingshellholders_zpsa84fa472.jpg


Normally a standard shell holder pictured below has a X dimension of .125. The competition shell holders would be .127, .129, .131, .133, .135 and the deck height where the case rests are lower. Meaning the competition shell holders do not push the case as far into the die as the standard shell holder. And as stated above the die still makes hard contact with the top of the shell holder removing any slop in the press.

techtalkshellhldr_zpsunhebtoy.jpg


Below I use the (plus) +.004 competition shell holder on the left to give me .003 shoulder bump on my .223/5.56 cases for my AR15 rifles. If the standard shell on the right had been used and set up per the dies instructions the case shoulder would have been bumped back .007.

shellholders_zps0f9bb695.jpg


I'm still using my Rockchucker I bought in 1973 and the competition shell holders remove any slop in the well used press.
Click to expand...

Adding to the clarity P51. Much obliged. I have a course of action to test now. Thanks!

Regards
Ron
 
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