Head Spacing, FL Sizing Die, Shoulder Bump

[16tpi]

1. If you post a response why don't you keep your replys relevant to the subject?
2. Forget the untelligible cryto-English - I think you are the only one that understands most of your posts.
3. If you are asked a question or receive a conflicting comment why don't you answer the question directly or limit your reponses to the subject matter without the deliberate obfuscation?

Please send him a PM, this is not for an argumentative, Im trying to learn new things from other people that want to talk about the main subject and what your opinions are about it.

Thanks

 

[ireload2]

Okay I have been reloading for years, maybe someone has noticed this before or maybe not. If you are bumping your shoulder on your brass, the question is WHY?

My initial die set up:
I will usually have once fired brass from a rifle with a longer chamber or I will expand case necks over size before resizing them. The initial sizing is done by comparing a fired case from my rifle to the cases being sized with a Hornady bushing gauge. I set the die so that I get .000 clearance. Using a stripped bolt, I size the case until I can feel a slight drag while closing the bolt with 1 finger. This setting is a little tedious to find because I often use once fired brass from an indoor range that comes from many different rifles. My goal is to set the die so it will size any brass to fit my rifle. Because the once fired brass varies by brand, by lot, by rifle it was fired in and several other variables I have to take extra care to get exactly the same size brass every time.
Variations in speed of sizing, amount and kind of case lube, length of dwell at the top of the stroke and number of strokes can cause small variations in the shoulder position. If you have a gauge that can measure the shoulder location to .001 use it on every case that you form or size in a lot of 100. You will find that your cases vary about plus or minus .002 total with most being within plus or minus .001. But that is still .002 variation. It takes extra care to get your sizing process to repeat to the limit of resolution of your calipers.
Once my die is set I don't know if my shoulder is being bumped, all I care is that the sized casea exactly match the chamber every time - of a bolt rifle. I will push the shoulder back about .001 to .002 shorter than the chamber for a lever, pump or autoloader. But I still do not measure my brass before it is sized once I have the die set unless I am just curious. I know that my fired cases can also vary +.000 to -.002 due to brass and differences in loads (from high pressure to plinking)

I have been looking to find the answer. In my line of work as an A Tool & Die Maker you have to give dies clearance to form the material the dies are forming. If it doesn't have the correct clearance the die will rip the material or leave it looking like a pie pan wrinkled up.

Forming self supporting cylindrical brass in a closed die is not the same process as a draw die

Now I have taken the time to setup my press to find out the why. I'm guilty of bumping the shoulder on my brass. I have a shell holder that will let me bump the shoulder back.

TEST

I set my die up using a standard shell holder, 0.125 of an inch from where the brass sits on the holder to where the holder bumps the die. Setup an indicator on top of the die and Zero it, to see what i am reading when i bump my brass with the bump that is required to get a smooth bolt closure. I put my bump shell holder in, and set the die to where i size the brass normally, -0.0105 of and inch is the reading i get when I size a brass. Now with that being said I use my GO GAUGE to see how far the die is set from there, the reading i get is -0.009 of an inch on the GO GAUGE. What is this go gauge? - there are a lot of variations
Now the math says I am bumping my brass a total of -0.0015 of an inch.

So if the head spacing is where the cause of need to bump the shoulder is, why not add .0015 to the back of the head space gauge?
Why do you want to modify the gauge? You could do this but your gauge is not longer an accurate gauge.

If it is the die, why not take it off the bottom of the die?
That is fine but the die is permanetly altered and may not be right for another chamber. You could trim the shellholder and keep them as a matched pair.





Your thoughts???

 

[16tpi]

Hey that's pretty good info there. Yes you are right, It is almost like a restike die to where you crisp a preformed part. with the exception of no bottom stake or punch. ALMOST...

The go gauge that you use to chamber the rifle with. To a point it will have a shut height for setting a die to form the brass to the chamber. Rather than guessing where to start or to use for measuring where your chamber is. But with the exception of what BoydAllen said.. the deviation is to far off to measure with the go gouge to do what I am wanting to do. I would in turn have to make a new gauge to set the chamber depth that will work with my dies. The tolerance of the saami specs is not that precision of a standard to set anything to. It is just a starting point or a reference. It is kind of like running a progressive die off the die stops and saying it is making a consistent part. Laughing Out Loud... Or with maybe even slugs under the die you know?? Not wanting to alter the gauge. It is a starting point to start measuring the chamber to let the chamber setter/ smith to know they are getting close. I say it should not have that much variation! Its like this, The powder and bullet is the punch that forces the brass to the chamber walls, or pressure from the ignition of it anyway. and the chamber is the form cavity. So we are restriking the brass. The brass has already been formed. I say there needs to be a FINISH GAUGE. And if it is gone over that is the smiths fault same for under size. If there is a finish gauge then there would be no bumming the shoulder, the brass will be right!! Variables in brass hey make that the same too!! This is not muzzle loading it is precision shooting we ALL are trying to accomplish.. If not take the restrictor plate out of nascar!! we see who a better driver, better engine builder, see how long the tires will last. All it the same aspect Chamber deep... see how long the barrel will last, see who can shoot the best see those bullets start smoking at mach4. Shoot a 50spsx bullet out of a 22-250 it will smoke it.. seen it done in a .223 not impressed with it. it was made for short barrels 10-16 I thinking off the top of my head again. maybe wrong.

Off subject.. do you know that the 327-350hp engine Chevy came out with in the 60's? Well if you don't let me enlighten you with a little bit of knowledge. If you wind the engine past 5700 RPM it starts to bend pushrods, and if you get it to wind high enough it will break the racker arms, I have seen that very camshaft shoot the pushrods thru the valve cover and break them like toothpicks. But before you do over rev the engine, @ about 3200 it comes to life starts to lay you back in the seat 5700rpm its shift or let off the little peddle!

Back on subject,

If you want consistent shooting it has to have consistent precision. From my point of view I see it as the bandaid has worn off and people, I myself have kept putting back on, because WHY? The problems are not being fixed. THE ANSWER IS IT WORKS... So does coke a mentos.

Make the Go Gauge A FINISH GAUGE, Make the die makers, do their job a little better to have a better too to work with, thus making better more consistent brass cases to run thru the dies.

Yes getting the right deck height that the shell holder smacks the bottom of the die and keep them together may need to be something a DIE MAKER as Redding, RCBS, Hornady, ... so on and so , may very well need to do. But the brass is going to have to change also. It needs to be the same from manufacturer to manufacturer. I know that different metals at different times have different properties, heat treat, different minerals little more zinc copper iron.. quality control...

Thru my years of reloading, I have found the most accuracy from reloading to with in the case neck tension and shoulder area. more so the neck tension than shoulder. Shoulder for pressure inconsistent, and tension for mostly flyer and inconsistent grouping. I make my own sizer ball in different sizes from carbide. case thickness i don't care about cause I know I can pull the ball thru and size it to what ever I want it to be.

Just my thoughts.

 

[16tpi]

Thank you for your help anyone else want to chime in?

 

[dkhunt14]

The only problem with the above post is brass changes with every firing. It is not the same hardness from the first firing to the fifth firing. The amount of spring back changes and so does the amount needed to size. Matt

 

[dmoran]

^^^ +1

To maintain a common length, I've had to adjust dies excess of .006" from new to 5 or 6 firings with some cases.
Donovan

 

[DanSavage]

You will eventually need to bump the shoulder on brass fired over and over, because it will stretch over time. I agree it is 2016 for pete's sake the numbers should be set in tone and all manufacturer's and smith's should have common number's available to work with for each chambering.

 

[16tpi]

You will eventually need to bump the shoulder on brass fired over and over, because it will stretch over time. I agree it is 2016 for pete's sake the numbers should be set in tone and all manufacturer's and smith's should have common number's available to work with for each chambering.

The case growing isn't the issue, but when the die cannot do its job, because the numbers are off in depth of chambering, both are machined yes, both have a specific depth yes, do the depths aid the other as it should no.

If a die is set to size a brass to fit the chamber, it is not going to change. If the die doesn't size the brass to fit your chamber after the die is set from a prior reload, then you chamber has moved or you moved your dies just enough to change the size of it. That is why I went with lock n load press, for the zero return from die changes. Every time I change dies it is where I left it when pulled. Your talking thousands of an inch, do you torque the die with a torque wrench to make sure it is at the same tightness every time? I know I don't. Hand tight. And to could have to reset from press stoke wear or flex. Sizing 5000 50bmg with your press and go back to .223 and I'm sure it will be a different number. I don't think the chamber is going to move, I don't think it is the brass fault either. That is all in die change setup repeatability. How consistent is the change?

I think the problem all lay within the depth of chamber. Think about it. I fire form the brass I'm using. Standard shell holder one of a name brand die. Why is it not sizing it correctly to begin with? Because I set it to a go gauge the is made to Saami specs, and the die maker made the die to Saami specs deviation .010-.022 as I recall some of the tolerances I seen on there site. The cheapest for me would be to make a new go gauge for the length I need to size the brass correctly in the more expensive dies, than a 20cent go gauge in material.

 

[dkhunt14]

You will eventually need to bump the shoulder on brass fired over and over, because it will stretch over time. I agree it is 2016 for pete's sake the numbers should be set in tone and all manufacturer's and smith's should have common number's available to work with for each chambering.

If you want smooth cycling of the bolt you need to full length bump every time. If you are not having too, your chamber must be big or your shooting cold loads. It doesn't matter if they hold numbers or not. The brass changes from cycle to cycle and the die needs changed to keep up with it. Matt

 

[JRS]

Order the WTC die and be done with it

 

[LHSmith]

4 pages and the disconnect still exists.......IMHO, you're directing the call to perfection in the wrong place. Instead of campaigning to get SAAMI to rewrite tolerances, if you want REAL improvement in accuracy that shows up on the target direct your energy and talents instead to the two biggest components that matter- Bullets and Barrels.

 

[16tpi]

4 pages and the disconnect still exists.......IMHO, you're directing the call to perfection in the wrong place. Instead of campaigning to get SAAMI to rewrite tolerances, if you want REAL improvement in accuracy that shows up on the target direct your energy and talents instead to the two biggest components that matter- Bullets and Barrels.

Bullets and barrels are like a man and a woman, if one don't like the other then it is not going to work. That simple. It's all in what the barrel likes, I have to Guns same chamber different mfrs to different loads.

 

[16tpi]

Order the WTC die and be done with it

How do they set there depth in there dies? If they set them the same way Redding dies I don't want them.

 

[JRS]

How do they set there depth in there dies? If they set them the same way Redding dies I don't want them.

The inserts are made to fit your brass. No other sizing die is in the same league.

 

[dkhunt14]

How do they set there depth in there dies? If they set them the same way Redding dies I don't want them.

They use shims on the bottom of the die. The machining on them is in a class of it's own. Matt

 

[LHSmith]

Bullets and barrels are like a man and a woman, if one don't like the other then it is not going to work. That simple. It's all in what the barrel likes, I have to Guns same chamber different mfrs to different loads.

And when you find a good barrel/bullet combination, it's amazing the groups one can shoot with brass that has subtle dimensional differences.....I see this every time I Fire Form unprepped PPC brass.

 

[BoydAllen]

To put a little perspective on all of this, I think that people need to understand that with the products and gunsmithing practices that are currently in use, averages of five groups shot at 100 yards, under the best conditions, by top shooters are under .2". Since I doubt that most, if not all who are reading this shoot with anywhere near this accuracy, perhaps the thought that there is a problem in the areas under discussion is simply wrong. I find it common that shooters get off on tangents in the pursuit of accuracy. When your results are not as good as the best, copy what they are doing, instead of making up "problems". Current brass, dies and gunsmithing methods work perfectly well. To speak to the issue of gauges, one first has to know the details of how they are used. I think that some on this discussion may not really understand those details at all.

 

[Patch700]

If a die is set to size a brass to fit the chamber, it is not going to change.

That is not the case , we are dealing with brass and it's ability to resist sizing changes constantly.

That is why I went with lock n load press, for the zero return from die changes. Every time I change dies it is where I left it when pulled.

That too is in my opinion a misconception , the lock n load setup is not an accurate way of setting and forgetting dies.. See reply #1.

I think the problem all lay within the depth of chamber. Think about it. I fire form the brass I'm using. Standard shell holder one of a name brand die. Why is it not sizing it correctly to begin with.

Stacked tolerences between mfg's is a start.

 

[fguffey]

1. If you post a response why don't you keep your replys relevant to the subject?

Well excuse me. I wanted to know who ‘you’ was/is.

And then I wanted to know what that meant. It was not my intentions to drive you to the curb.

F. Guffey

 

[DanSavage]

Order the WTC die and be done with it

WOW! That is one whale of a die! I really like it ,,, maybe someday I could afford it, would probably have to buy a press for it too. For me it's just working on table manner's and feeding the barrel's for the time being.LOL