question about headspace inconsistency

[PlinkIt]

Disclaimer ... I am new to reloading!!!

I just finished full length resizing a 40 round batch of 7mm rem mag brass..

now my question is should my headspace reading on each individual piece of brass not be the same?

I worked the first piece of brass by slowly increasing the depth on the die until I went from the fired case measurements of around 2.115-2.117 headspace

down to 2.112 which was my .003 goal...

now set the die locked it down and measured the next piece and 2.111 so I was happy with that and proceeded to resize the rest of the batch.

Now my question still is it normal for the same die on the same set of brass that was locked down the entire batch to have this much of a swing in result? I have 2.108-2.114 here and one stubborn piece that reads 2.116 and I tried to resize it several times... whats the deal????? is this normal is it all good to go? did I do something wrong?

 

[SONIC SAAMI]

I think you are to go....Load and shootem

 

[918v]

Press linkage slop induces variance. Brass hardness induces variance. The only way to cure it is to anneal and bottom out the die against the shell holder. This imparts too much headspace, but there are Redding Competition Shell Holders having incrementally taller deck height which allow you to bump the shoulder in precise .002" increments.

Also, lube the inside of the neck, otherwise the expander ball will pull the shoulder forward.

 

[witchhunter]

Try slowing down the amount of time your brass spends in the sizer die. Like a 5 or 10 count and see if that helps. Some brass has more spring back than others. You are using all the same headstamp right?

 

[PlinkIt]

I think you are to go....Load and shootem

thanks

Press linkage slop induces variance. Brass hardness induces variance. The only way to cure it is to anneal and bottom out the die against the shell holder. This imparts too much headspace, but there are Redding Competition Shell Holders having incrementally taller deck height which allow you to bump the shoulder in precise .002" increments.

Also, lube the inside of the neck, otherwise the expander ball will pull the shoulder forward.

I did lube the inside of the neck, but certainly didn't bottom out the die on the holder.. guess I have some purchasing to make if I actually want them to be the same huh?... would the plumbers candle be enough of a heat and cool to help this or will it need a real annealing?

Try slowing down the amount of time your brass spends in the sizer die. Like a 5 or 10 count and see if that helps. Some brass has more spring back than others. You are using all the same headstamp right?

2 20 round boxes from the same lot, and some of the pieces that stayed on the larger side I even tried to run again without it getting any smaller..

I will try the count idea but I am not sure it will help as I tried to resize some pieces repeatedly that were on the larger size without any luck in them getting to the desired size..

 

[918v]

I use a microtorch to anneal. They like $10 at a hardware store. Candles don't get hot enough to anneal. The comp shell holder set is pricy but worth it.

 

[Twoboxer]

. . . would the plumbers candle be enough of a heat and cool to help this or will it need a real annealing? . . .

Neck to 750 without bringing the rest of the case above 450. If you don't hit 750 (long enuff) there's no useful annealing . . . if the rest of the case gets over 450 it may not be able to take the next firing.

Just wanted to make sure you read up first, and didn't jump right into it.

 

[woojos]

The only way to cure it is to anneal and bottom out the die against the shell holder. This imparts too much headspace.

This may be part of the problem.

I've seen a similar .003" variation in headspace in my brass after sizing. It may be springback, but I think it is inconsistent pressure at the top of the ram. If I screw the die another 1/4 turn until the press cams over, I end up over sizing, so I haven't tried it to see if it solves the variation problem. But, playing with how hard I pull the handle I can almost predict if the bump will measure over or under my goal.

Being as consistent as possible with it, I still see the variation.

It almost seems like a need a Redding shell holders with -.002" increments, so I can set it to cam over, then reduce the shell holder height to give me the right bump without overbumping.

 

[918v]

Exactly.

 

[haroldwilson]

Comp shell holders are thicker not thinner. They will reduce your shoulder bump in .002 increments.

This should allow you to get cam over and much better consistency.

 

[PlinkIt]

I use a microtorch to anneal. They like $10 at a hardware store. Candles don't get hot enough to anneal. The comp shell holder set is pricy but worth it.

Neck to 750 without bringing the rest of the case above 450. If you don't hit 750 (long enuff) there's no useful annealing . . . if the rest of the case gets over 450 it may not be able to take the next firing.

Just wanted to make sure you read up first, and didn't jump right into it.

I had just started reading into the annealing process and the only thing I saw anyone speak of that I had access to try here at the house was some heavy candles so I tried it with a couple junk cases spinning it in fingers because I had read it somewhere on here but it didn't even get the neck anywhere near hot enough before my fingers were telling me to throw it in the water.. so I figured I will wait a little longer and get a little more reading in on the best way to get the annealing process started.. I figured I could get a few reloads though the press and learn what I am doing before I really call myself trying to make some high quality rounds...

This may be part of the problem.

I've seen a similar .003" variation in headspace in my brass after sizing. It may be springback, but I think it is inconsistent pressure at the top of the ram. If I screw the die another 1/4 turn until the press cams over, I end up over sizing, so I haven't tried it to see if it solves the variation problem. But, playing with how hard I pull the handle I can almost predict if the bump will measure over or under my goal.

Being as consistent as possible with it, I still see the variation.

It almost seems like a need a Redding shell holders with -.002" increments, so I can set it to cam over, then reduce the shell holder height to give me the right bump without overbumping.

well I am glad it wasn't just me that has the issue then, and I guess I will have to live with the spread until I can get the dies in each caliber.. I cant really tell anything by the handle pressure but again I am new at this.. it did confuse me how I could run the same brass again and it didn't manage to get any smaller though.. i would have figured if it was some inconsistency then a couple more cycles through the press would either get it where I wanted or make it too small..




Thanks for the help y'all!!!!!!!!!!!!

 

[Victor N TN]

After those rounds are fired, try when you size them hold the handle down for a few seconds. Sometimes being held in the die will help the brass all come closer to the same dimension. I know on some of my military brass I run it through a small base die. I double stroke it, holding it at the top of the stroke for just a second. Then do the whole thing again holding the press handle down again. This seems to help with getting the brass moved to where I want it.

Maybe it will work, or maybe not. But you might give it a try to see how it works in your circumstances.

Good luck.
Victor

 

[PlinkIt]

Ok two people noted on cam over now let me make sure I understand here... you are simply referring to when the handle is pushed until the fulcrum max is reached and then there is a slight movement where pressure is almost released when still moving the handle downward..

I am going beyond this point now because there is no bottoming out going on between the die and the shell holder..

now my question here would be what is the objective? to get the thicker shell holders and make it so that the press just barely does this cam effect? or to use the die to stop the press just short of the cam effect?

so am I understanding the cam over term correctly? and what is the preferred method?

Comp shell holders are thicker not thinner. They will reduce your shoulder bump in .002 increments.

This should allow you to get cam over and much better consistency.

If I screw the die another 1/4 turn until the press cams over, I end up over sizing

 

[PlinkIt]

I will be trying the couple seconds of holding with the next batch, but I did try the double press on all the ones that didn't size as small as I wanted them. I also tried turning them 1/4 turn and pressing again to see if it would help.. I still had one stubborn one that refused to go lower than 2.116 no matter what I did to it.. I believe at this point I have put that one through the press about 6 times just trying to see if there was something I could do different to get that one to end up where I wanted it without actually moving the die

After those rounds are fired, try when you size them hold the handle down for a few seconds. Sometimes being held in the die will help the brass all come closer to the same dimension. I know on some of my military brass I run it through a small base die. I double stroke it, holding it at the top of the stroke for just a second. Then do the whole thing again holding the press handle down again. This seems to help with getting the brass moved to where I want it.

Maybe it will work, or maybe not. But you might give it a try to see how it works in your circumstances.

Good luck.
Victor

 

[918v]

I don't cam over. I screw the die down past the cam over point. I can see and feel the bottom of the die stop against the shell holder and see and feel the shoulder being bumped.

You don't need the leverage of cam over. The case is weak. It will give. I use imperial sizing wax.

 

[Suasponte]

Terry

 

[PlinkIt]

See now that's why I ask questions on here.

Because you guys really deliver on the answers!

watching him that might really be my down fall.... I have reloaded the batch already at this point but I will be trying the 3 count and turn method and 3 count next time before I buy the redding shell holders, that would be nice if it was my only problem

 

[PlinkIt]

Ok guys I shot up the batch that was loaded and proceeded to try this again.. This time I used the counting method (counted to five), but still have some cases that seem to refuse to be sized the same as the others.. For the majority my brass is more consistent.. But these few are just refusing to match the rest?... Even tried letting one sit it the die for about sixty seconds.. Still refuses to match the other brass by about .006 of an inch.. So is this only resolved by the redding shell holders? Or is there anything else I may be missing?

 

[MitchAlsup]

now my question is should my headspace reading on each individual piece of brass not be the same?

Ideally, yes.

I worked the first piece of brass by slowly increasing the depth on the die until I went from the fired case measurements of around 2.115-2.117 headspace

down to 2.112 which was my .003 goal...

What you have here is a failure to think the problem through! ! !

What you wanted is to size the 2.117s down to 2.114 (-0.003) but size the 2.115s down only to 2.114 (-0.001). See, now they are both the same--which is good.
Secondly, you just barely touched the shoulders on the short ones, improving lifetime of the cases.

now set the die locked it down and measured the next piece and 2.111 so I was happy with that and proceeded to resize the rest of the batch.

Now my question still is it normal for the same die on the same set of brass that was locked down the entire batch to have this much of a swing in result? I have 2.108-2.114 here and one stubborn piece that reads 2.116 and I tried to resize it several times... whats the deal????? is this normal is it all good to go? did I do something wrong?

You have oversized the necks/shoulder. Since this is a belted magnum, the shoulders will be 'blown' back long on the next firing.

As to the distribution, the picture looks rather normal for a person slamming cases through the resizing die.
If you want tighter distribution, lube properly, and use the nerve endings in your lever arm to feel the cases getting sized. Neither move too fast, not apply excessive force, but attempt to use the same force on each and every case.

 

[PlinkIt]

Appreciate the help guys and think I figured out where my problem was at..

not enough lubricant.. thought the slightly gritty feeling was normal for the magnum brass..

little more liberal with the lube and all things fell into place perfectly, thanks again guys!