Setting up dies "properly"

Yes, all of the new unfired brass is 2.101 which appears to be .008 UNDER maximum SAAMI specs for this cartridge if I'm reading their spec sheet correctly. That would mean that from unfired to once fired, the brass is lengthening by .0175. Seems excessive to me as well but I've measured and remeasured and that's what I'm getting from it.

I have also experienced case head separation after only a few firings in one of my Model 700 270WIN rifles. So, obviously I cannot blame everything on the brass nor the rifle and somewhere it is my reloading process that is contributing to the issue. I have always set my dies up as directed in the manual that came with the dies.
 
have one, they work
I shoot a 230 at 2900 fps on a 26.5 bbl.
not a mild load.
Measure your fired 7mm mag cases just above the belt before and after resizing, measure the same place with unfired cases. Compare the measurements to determine if your sizing die is returning the area above the belt close enough to spec, .513". Then Research Belted Magnum Collet resizing die by Innovative Technologies . I'm not advertising for this guy, but just thinking about investing in one of his dies for my 300 Win Mag.
 
I just finished reading this thread:


In many of the posts, users mention "properly set up dies". What specifically does this mean?

A little back story on myself...I have been reloading for a number of years now. No competition shooting or anything like that but lots of hunting here in the west.

Recently I had some cases split (case head separation) on my 7mm mag after only 3-4 firings. I've always loaded for this rifle the same way (once load development was done, which didn't take long). Nothing extreme, well within max published load, shoots fantastic in this rifle.

160gr Accubond over 61gr of RL-22 using Federal or Winchester primers.

So, I begin researching why this may be happening. Thin brass (bad batch), excessive chamber specs, over working the cases, etc. all come up as likely culprits.

I have always FL sized my brass after each firing. Many suggested I back my dies out so that I am just "bumping" the shoulder back about .002" or so. Fair enough, easy to do.

The thing that has me really hung up is that my fired brass measures 2.1185avg. During the sizing and "bumping" process it grows to as much as 2.124 before I make contact with the shoulder and it begins to shrink. So in my mind, the stretching (damage) is already done before I even get the neck sized.

New brass measures 2.101, btw.

So, I buy a neck sizing die. I haven't used it yet but people are recommending I not use it for hunting loads...back to square 1.

BTW, the rifle will close on cases 2.120 and maybe even higher, I ran out of fired brass before I got to the top end of its chamber dimensions.

So am I supposed to be bumping shoulders .002 +/- from my fired case size (2.1185) or from the max my chamber will accept or from the max length my die makes them become (2.124) during the sizing process?

So confused. Sorry for the long post but if I've learned anything from forums, it's that more information usually generates better help.

Thanks.

First you have to understand how belted magnums deform in your chamber. Measure a brand new case, once fired and twice fired. When I say measure it, I mean measure right above the belt. You will notice that in each case the brass will deform in every direction.
Look at
Belted Magnum
Collet Resizing Die


 
New brass measures 0.5090 above the belt. Measures 2.101 +/- to the datum line.
4x fired un-sized measures .5145 above the belt. Measures 2.1210 to the datum line.
1x Fired measures .5125. Measures 2.1185 to the datum line.

So, it appears that my dies are not sizing all the way to the belt which is not surprising as I can clearly see a line where the die stops. It is sizing past the area where I am getting separation however.

What would that expensive collet die do that my current FL dies does not?
Obviously it will size all the way to the belt but will that just cause the separation to begin lower on the case? How does it prolong case life?

Thanks for the help all, working to make this whole process better in the long run.
 
I just finished reading this thread:


In many of the posts, users mention "properly set up dies". What specifically does this mean?

A little back story on myself...I have been reloading for a number of years now. No competition shooting or anything like that but lots of hunting here in the west.

Recently I had some cases split (case head separation) on my 7mm mag after only 3-4 firings. I've always loaded for this rifle the same way (once load development was done, which didn't take long). Nothing extreme, well within max published load, shoots fantastic in this rifle.

160gr Accubond over 61gr of RL-22 using Federal or Winchester primers.

So, I begin researching why this may be happening. Thin brass (bad batch), excessive chamber specs, over working the cases, etc. all come up as likely culprits.

I have always FL sized my brass after each firing. Many suggested I back my dies out so that I am just "bumping" the shoulder back about .002" or so. Fair enough, easy to do.

The thing that has me really hung up is that my fired brass measures 2.1185avg. During the sizing and "bumping" process it grows to as much as 2.124 before I make contact with the shoulder and it begins to shrink. So in my mind, the stretching (damage) is already done before I even get the neck sized.

New brass measures 2.101, btw.

So, I buy a neck sizing die. I haven't used it yet but people are recommending I not use it for hunting loads...back to square 1.

BTW, the rifle will close on cases 2.120 and maybe even higher, I ran out of fired brass before I got to the top end of its chamber dimensions.

So am I supposed to be bumping shoulders .002 +/- from my fired case size (2.1185) or from the max my chamber will accept or from the max length my die makes them become (2.124) during the sizing process?

So confused. Sorry for the long post but if I've learned anything from forums, it's that more information usually generates better help.

Thanks.

Fifty years from now these questions will still be asked! Let me say this from many years of Bench rest shooting.

I was once a believer in Bumping back shoulders as it was almost a fad until shooters came to realize the reality of it all. Amazingly, what many don't know is that bumping the neck to factory specs happen automatacly when you full length size your brass. When I stopped neck sizing and shoulder bumping my groups inproved dramaticaly. Try to remember that the rifles and ammo are all to sammi specks. By bumping the shoulder back you deviate from thoes specs and are now allowing the dies to change the dementions from what should have been to what is as a result. I know full well that my comments here are going to stir up a hornets nest but so be it.

Used to be, when using an auto rifle we would always full size all our brass or "Fire form" the brass to fit the chamber. If you look at this we have at least 4 different methods of sizing brass, full length, neck sizing, bump sizing and fire forming. THEY CAN'T BE ALL CORRECT, but they sure sell a bunch of new dies!
 
New brass measures 0.5090 above the belt. Measures 2.101 +/- to the datum line.
4x fired un-sized measures .5145 above the belt. Measures 2.1210 to the datum line.
1x Fired measures .5125. Measures 2.1185 to the datum line.

So, it appears that my dies are not sizing all the way to the belt which is not surprising as I can clearly see a line where the die stops. It is sizing past the area where I am getting separation however.

What would that expensive collet die do that my current FL dies does not?
Obviously it will size all the way to the belt but will that just cause the separation to begin lower on the case? How does it prolong case life?

Thanks for the help all, working to make this whole process better in the long run.
Follow the link Mc Fraser has in the post #18 ( Innovative Technologies) . It will take you to that web site. He has a whole lot of questions and answers already listed and he answered the ones I asked promptly.
 
Fifty years from now these questions will still be asked! Let me say this from many years of Bench rest shooting.

I was once a believer in Bumping back shoulders as it was almost a fad until shooters came to realize the reality of it all. Amazingly, what many don't know is that bumping the neck to factory specs happen automatacly when you full length size your brass. When I stopped neck sizing and shoulder bumping my groups inproved dramaticaly. Try to remember that the rifles and ammo are all to sammi specks. By bumping the shoulder back you deviate from thoes specs and are now allowing the dies to change the dementions from what should have been to what is as a result. I know full well that my comments here are going to stir up a hornets nest but so be it.

Used to be, when using an auto rifle we would always full size all our brass or "Fire form" the brass to fit the chamber. If you look at this we have at least 4 different methods of sizing brass, full length, neck sizing, bump sizing and fire forming. THEY CAN'T BE ALL CORRECT, but they sure sell a bunch of new dies!

So, if all 4 cannot be correct (truth is always a matter of perspective) which one would you propose is the correct one? Surely we can't just leave the brass as is and keep shooting it endlessly. Some form of sizing is going to have to take place at some point.

FL sizing my brass...and I do mean FULL Length as in installing the dies in the press exactly as directed in the die instruction manual has gotten me to where I am and the reason for this thread. Not bumping the shoulders just a little, not sizing only the neck, not keeping the cases fire formed, but running the case into the die until it will not go further and then reloading it.
 
Fifty years from now these questions will still be asked! Let me say this from many years of Bench rest shooting.

I was once a believer in Bumping back shoulders as it was almost a fad until shooters came to realize the reality of it all. Amazingly, what many don't know is that bumping the neck to factory specs happen automatacly when you full length size your brass. When I stopped neck sizing and shoulder bumping my groups inproved dramaticaly. Try to remember that the rifles and ammo are all to sammi specks. By bumping the shoulder back you deviate from thoes specs and are now allowing the dies to change the dementions from what should have been to what is as a result. I know full well that my comments here are going to stir up a hornets nest but so be it.

Used to be, when using an auto rifle we would always full size all our brass or "Fire form" the brass to fit the chamber. If you look at this we have at least 4 different methods of sizing brass, full length, neck sizing, bump sizing and fire forming. THEY CAN'T BE ALL CORRECT, but they sure sell a bunch of new dies!
This begs the obvious question ... which is the correct way? I've been reloading for my AR's for years and therefore have FL resized every case after every firing. I am only just now getting into bolt action shooting and subsequently, reloading for them. In some of my research I've also come to question the need and effectiveness for bumping the shoulder, and I'm not at all convinced it's necessary, ever. I have a Forster FL sizing die for my wildcat 7mm SST, but I also have the Lee neck collet die. So how should I proceed once I begin reloading this cartridge?
 
Follow the link Mc Fraser has in the post #18 ( Innovative Technologies) . It will take you to that web site. He has a whole lot of questions and answers already listed and he answered the ones I asked promptly.

I read the whole story of how he came up with this idea and how it serves the purpose of resizing that little bit of the case wall that other dies miss. Seems like a good way to resolve an issue where your brass has expanded in that area to the point it will no longer fit in your chamber. Shoot them, FL size them until they won't fit and then use this collet to shrink the base so you can shoot them some more....

That's all good and well but it does not solve the issue of the case stretching towards the neck and thinning out in the area where case head separation takes place. In fact, this tool is supposed to be used after you have already full length sized the brass using a normal die set. I do not grasp how it will stop the brass from thinning out in this area above the belt.

Feels like I am missing something simple...need to continue my research. I appreciate the discussion and I am reading every post and suggestion and taking them into account with the overall sizing process so I can learn to do this the right way every time.
 
sorry, but just not the best advice
saami spec,, die maker setttings old school accuracy.
we know a lot more today.
why repeat the errors of the last 40 years

Fifty years from now these questions will still be asked! Let me say this from many years of Bench rest shooting.

I was once a believer in Bumping back shoulders as it was almost a fad until shooters came to realize the reality of it all. Amazingly, what many don't know is that bumping the neck to factory specs happen automatacly when you full length size your brass. When I stopped neck sizing and shoulder bumping my groups inproved dramaticaly. Try to remember that the rifles and ammo are all to sammi specks. By bumping the shoulder back you deviate from thoes specs and are now allowing the dies to change the dementions from what should have been to what is as a result. I know full well that my comments here are going to stir up a hornets nest but so be it.

Used to be, when using an auto rifle we would always full size all our brass or "Fire form" the brass to fit the chamber. If you look at this we have at least 4 different methods of sizing brass, full length, neck sizing, bump sizing and fire forming. THEY CAN'T BE ALL CORRECT, but they sure sell a bunch of new dies!
 
most mag brass grows to a point it cannot be resized with std dies.
this tool is for GOOD brass that is too fat at the belt. period.
but it will not fix poor sizing and case failure.
brass flows forward on firing. too much sizing means it flows more every time till it thins and fails at the base

I read the whole story of how he came up with this idea and how it serves the purpose of resizing that little bit of the case wall that other dies miss. Seems like a good way to resolve an issue where your brass has expanded in that area to the point it will no longer fit in your chamber. Shoot them, FL size them until they won't fit and then use this collet to shrink the base so you can shoot them some more....

That's all good and well but it does not solve the issue of the case stretching towards the neck and thinning out in the area where case head separation takes place. In fact, this tool is supposed to be used after you have already full length sized the brass using a normal die set. I do not grasp how it will stop the brass from thinning out in this area above the belt.

Feels like I am missing something simple...need to continue my research. I appreciate the discussion and I am reading every post and suggestion and taking them into account with the overall sizing process so I can learn to do this the right way every time.
 
im thinking its your dies body angle fits tight at full shouder bump in comparison to you chamber angle ..

if your hornady die sizes neck and bumps shoulder .. do that then, full length only deep enough for the body to push in enough to chamber (shoulder wont contact )

then ink , test FL alittle more . ink test .. size out the ink contact .. i think you are over working the .2 up from belt ares too much .. on the harder not annealed part of the brass ..

even though your. 2 up from belt measurments are close

just brain storming out loud
 
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thank again rsmithsr that makes a bit more sense.

For someone like me that has observed a once fired case flow from the fired size of 2.1185 up to as much as 2.124 during the sizing process before being bumped back to the chosen size of say 2.1165 (.002" bump back for example only, but also most often the suggested bump back amount) and is not having issues with the case being tight in the chamber but is experiencing case head separation after only a few firings....what would you suggest I do differently?

I have two pieces of once fired brass that I resized to larger than they were after firing (went from 2.1185 to 2.120) that show a faint line where the case is thinning and wanting to separate. I plan to cut them in half to confirm what I am seeing but if I can't even resize a piece of brass one time something is not right.

And I know I've mentioned it before but this is not the first time I have reloaded for this rifle. I just pulled at least 50 pieces of brass that have been shot in this rifle with this exact load out of my scrap pile. They have all been shot a maximum of 4 times (I assume because that is my self imposed maximum reloading cut off) and although I have not sized them after that 4th shot, they do not show any signs of thinning yet. Chase the tail.....

I had a local gun builder check my chamber with their gauges and it will not close on the No-Go gauge but will on the Go gauge. At least I know my chamber is within spec, even if it's at the maximum for tolerances.
 
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