Sizing Cases?

[Howa 9700]

First some background. About 2 months back, made the executive decision to start reloading rifle again after a 50 year break. Had a few residual items, but with some careful shopping and a little help from my friends, have been able to accumulate almost all I need to get started. Only thing missing is a pound or two of select fresh powder.....and still looking for that.

First run at setting up sizing dies was yesterday. New RCBS dies (270 Win) on a Lee Classic breech lock press.....using the breech lock inserts. Brass had been cleaned and de-primed. Was using what I know was once fired brass from the same box of factory Remington Peters brass.

Goal was to set headspace shoulder bump back 2 thousands......these from and for same bolt gun that fired it the first time. Was using both Hornady case comparator gauge and a Wilson headspace/ case length gauge. Initial case length before sizing looked to be within specs.

Measured 10 cases and got a good idea on what existing headspace was, so knew how much I needed to end up with. 7 of 10 were the same.....other 3 were only .001 less.

Instructions for setting up dies says to raise ram to uppermost point, then screw dies down to touch......then lower ram and screw in dies about 1/8 to 1/4 turn more......enough to get ram to cam over, and that is where you set your dies. That seems to be the universal manufacturers instructions for setting up sizing dies.

I set dies to touch, and stopped there....no additional turn. I then sized a case and measured it, found no shoulder bump......so then screwed die down about 1/8th turn......and got my 0.002 shoulder bump. Then set lock ring and set screw. Nothing moved.

Sized a case, and it held up......0.002 shoulder bump. Did another.....same. Did several more.....then went back and measured.......and started finding way more bump. Like .004 and .005. Nothing had changed.......and still no cam over. The only difference I could detect to cause any difference was the degree to which I pushed on the ram at the bottom of the stroke. Firm or very firm, yet still no cam over.

So question / observation is........there seems to be a total disconnect between instructions that are loosey / goosey as far as any precision is concerned, and the minute differences that put you in and out of spec when you get out even basic measuring devices.

Tested the entire lot with Wilson gauge and after trimming, all are within specs of the gauge, so feel they will load OK, but still ended up with more variation that I expected.

So now wondering where to look for source of variation. Problem with my setup.......or a problem with Lee system and press?

 

[Dale Alan]

Could be as simple as brass , without being annealed spring-back comes into play . Were the variations all in a row or random through the process ?

 

[MEHavey]

What lube ?

 

[Howa 9700]

A row of 10.......variation throughout.......which at the time I couldn't see, but after the fact, and thinking it over.....seems to point to simple difference in pressure at bottom of stroke. But if that were the case.....errrrr.....issue, if I followed the directions and went so far as even a slight cam over, it would way over cook them as far as head space is concerned.

Redding die wax. Didn't have any hint of a stuck case......nor dimpled from too much lube.

Checked all cases with a bullet before sizing.......and necks were tight to begin with. BTW, gun is a lightly used Rem 700, so action remains tight.

 

[JFrank]

Deleted

 

[Wreck-n-Crew]

Cam over is only on certain presses and not that one, it is a dead stop design. So if pressure does vary some on the stroke it will show in the shoulder bump.

 

[AJC1]

A row of 10.......variation throughout.......which at the time I couldn't see, but after the fact, and thinking it over.....seems to point to simple difference in pressure at bottom of stroke. But if that were the case.....errrrr.....issue, if I followed the directions and went so far as even a slight cam over, it would way over cook them as far as head space is concerned.

Redding die wax. Didn't have any hint of a stuck case......nor dimpled from too much lube.

Checked all cases with a bullet before sizing.......and necks were tight to begin with. BTW, gun is a lightly used Rem 700, so action remains tight.

The reeding sizing wax is the source of your variation. I recertified this 113 times on my 308 cases two days ago. I never got dents but my cases trended shorter. Dont lube the neck at all. I observed. 004 down trend in my numbers. Still safe but not as consistent as I would like. I removed my expander ball so my process may vary from yours. I expand with a mandrel after I chamfer and debur.
Another thing I do that may be different is die dwell time. Push in the case for a repeatable time. I use 20 seconds. I should anneal but I'm not there yet.

 

[MEHavey]

^^^^^ THIS ^^^^^
Sizing force (and therefore sizing if no cam-over/bottom out) is no small function of lube conditions.
I suggest RCBS case lube/or clone for more uniformity throughout the process.

 

[JFrank]

Deleted

 

[lightman]

First some background. About 2 months back, made the executive decision to start reloading rifle again after a 50 year break. Had a few residual items, but with some careful shopping and a little help from my friends, have been able to accumulate almost all I need to get started. Only thing missing is a pound or two of select fresh powder.....and still looking for that.

First run at setting up sizing dies was yesterday. New RCBS dies (270 Win) on a Lee Classic breech lock press.....using the breech lock inserts. Brass had been cleaned and de-primed. Was using what I know was once fired brass from the same box of factory Remington Peters brass.

Goal was to set headspace shoulder bump back 2 thousands......these from and for same bolt gun that fired it the first time. Was using both Hornady case comparator gauge and a Wilson headspace/ case length gauge. Initial case length before sizing looked to be within specs.

Measured 10 cases and got a good idea on what existing headspace was, so knew how much I needed to end up with. 7 of 10 were the same.....other 3 were only .001 less.

Instructions for setting up dies says to raise ram to uppermost point, then screw dies down to touch......then lower ram and screw in dies about 1/8 to 1/4 turn more......enough to get ram to cam over, and that is where you set your dies. That seems to be the universal manufacturers instructions for setting up sizing dies.

I set dies to touch, and stopped there....no additional turn. I then sized a case and measured it, found no shoulder bump......so then screwed die down about 1/8th turn......and got my 0.002 shoulder bump. Then set lock ring and set screw. Nothing moved.

Sized a case, and it held up......0.002 shoulder bump. Did another.....same. Did several more.....then went back and measured.......and started finding way more bump. Like .004 and .005. Nothing had changed.......and still no cam over. The only difference I could detect to cause any difference was the degree to which I pushed on the ram at the bottom of the stroke. Firm or very firm, yet still no cam over.

So question / observation is........there seems to be a total disconnect between instructions that are loosey / goosey as far as any precision is concerned, and the minute differences that put you in and out of spec when you get out even basic measuring devices.

Tested the entire lot with Wilson gauge and after trimming, all are within specs of the gauge, so feel they will load OK, but still ended up with more variation that I expected.

So now wondering where to look for source of variation. Problem with my setup.......or a problem with Lee system and press?

Before you drive yourself crazy or pull your hair out try chambering a few cases in your rifle. If they chamber ok using your method lock your die down and call it good.

Back before the measuring craze hit I would turn my sizing die down and leave a gap about the thickness of a business card between the die mouth and the shell holder. I would size a case and look at the neck with a magnifying glass. You can see a ring where the die sized the neck. I would continue to move the die down until the ring met the shoulder and then give it about 1/8th more turn. If the sized cases would chamber ok I locked the die down and called it good. This method has worked well for me for a number of years.

The instructions that came with your dies are to ensure that your ammo would fit all industry standard chambers. My method, and your method of measuring are for your particular firearm and is to minimize case stretch.

 

[CMB]

Redding makes a "competition shell holder" set. Basically the shell holders are graduated in .02 increments from .02 through .10. I just got a set so my experience is only a week old but this set allows you to make die to holder contact yet still regulate the shoulder bump. For me to get .002-.003 set back I use the .10 shell holder. This is with the Lee classic single stage press which only sizes brass.

Some folks report the importance of shell holder contact to "square" the die in the press which is the main reason I picked them up. Prior I used the back it off method your explaining and it worked fine for years. Maybe I missed it but is all the brass the same head stamp- I see same- box of Rem brass......

Does RCBS use a sizing ball like Redding? Is the up stroke pressure consistent from case #1 through case #10? Is it possible the sizing ball got dirty and is stretching the case slightly?

Here's to rambling thoughts-

 

[Howa 9700]

The Lee press was a lightly used near gift a guy made available to me, but didn't come with instructions. But I found some online and after reading those again, I am now aware this press does not cam over. Instructions did say, however, to screw die down to touch, lower ram, then increase depth by 1/4 to 1/2 more turn. That would have way over cooked my cases.....probably out of spec. Again, what seems to be a disconnect between what shows up in instructions, vs. what happens when you put those instructions into practice.

I had been lead to be believe the Redding lube was the pick of the litter? I just swiped a finger across the top, then rubbed that on my thumb, then twirled the cases between thumb and finger. Didn't look like much lube at all. I did lube a few necks with what residual was on my fingers after I hit the case........still have some flashbacks to when my Dad started loading all those years ago and first thing he did was get a case stuck for lack of lube. Pretty much vowed not to repeat that mistake.....but if lubing the necks is just as bad, will have to show some restraint next time.

Rifle isn't here, but by coincidence, traveling today to where it is........and will try to chamber some of my resized (and wiped clean) brass.

 

[MEHavey]

lead to be believe the Redding lube was the pick of the litter?

If that's Imperial Sizing Wax relabeled, many like it. I personally use it lightly to size lead bullets in Lee push-through dies.

But when used in a case sizing operation where you cannot fully bottom out on the die
(i.e., can't 'cam-over'), you're in a crapshoot as to varying sizing force vs press spring.

Grab some RCBS Case Lube and try it.


.

 

[CMB]

There's something about that Lee press that won't let it cam over. It must be at the very top of its stroke when the arm is down. I thought it was the way I had it mounted to the bench in letting it move but that's not the case.

 

[jmorris]

One doesn’t need a lot of measuring tools or gauges to set up a size die for a particular rifle, using this method. I suppose you could look at the rifle as the No Go/Go gauge because that’s exactly the way you are using it for setting up your die but it’s not an extra purchase required.



The way you use measuring tools or the tools themselves will have zero effects on the results you get using the above method, obviously, because they are not used.

FWIW sometimes a single firing won’t have a case fully formed to the chamber. Why places That make custom dies want cases that have been fired at least 3 times from the chamber.

 

[NMexJim]

I think the video method is just fine to a point, and, if fact, have used it. My problem is that it does not use a CBTO (OAL like a Hornady, etc) gauge to ensure you know the amount of shoulder set-back. If you get good results with it, great. Read no further. I just like repeatable results.

You said that you touch the ram with the F/L die, and then lower the ram, and finally, turn the die in 1/8 or a 1/4 turn for cam over. That method should give you complete full-length sizing, and should also take the case back to SAAMI specs including the shoulder. Getting .002 shoulder set-back would be a fortunate turn of events - may be your rifle chamber is a tad tight. Usually, you have to screw the die out to reduce the amount of shoulder set-back.

You've probably just gotten into the feel of the process are have been getting full press ram movement. Could be lube working too.

TECH Tip: How to Set Your Dies for Correct Shoulder Bump « Daily Bulletin (accurateshooter.com)

This is a short article that might help. There is a lot out there on the correct die set.

 

[Howa 9700]

Case lube is Imperial die sizing lube and in fine print at the bottom, it says "part of the Redding product family", or some such thing. So I have been referring to it as Redding lube, but it is Imperial.

Tried a couple sized cases in the rifle, and both chambered fine with no issues. I suspect all will load and fire fine, provided I get the remaining steps right. That is on hold until some powder shows up.

But to clarify what I was doing in the first place, my understanding of process is......I can either size for Sammi specs so loaded rounds will function and load like factory ammo in all rifles.......or.......I can size to this specific rifle. Reason for doing latter is two fold......one to lesson amount of "working" cases get when fired to extend life of cases. Second is to limit amount of expansion and movement of cases to remove that variable.....and thus in theory improve accuracy. Since I only have one rifle in each caliber I'm loading for, and wanted to get best accuracy out of each, I was going for best fit. Ambitious move......going from entry level expertise to advanced level techniques......but that was the goal.

I have seen numerous ways of doing this. Stripping the bolt (which I have never done) and fitting case to chamber by using trial and error seems like a precise way of doing it, provided all cases fit. Loaded ammo will be used mostly for hunting (or target practice to be proficient at hunting), so if I err on one side or the other, it will be a fit that always chambers. And if whatever I end up with will achieve 1 moa accuracy, victory will be declared and we go home.

 

[NMexJim]

Let's cover some basics.

• Are you using a reloading manual and, if so, which one?
• What bullets do you plan to use (include product number if you have it or a picture).
• And what powder?
• The dies are new and they came with instructions, correct?

And, what is the rifle?

I think the best thing to do is get you back into the groove with basic reloading before you try a lot of load fine-tuning. The cases that were over-bumped at the shoulder should be fine especially if they chambered.

Set your dies just as the instruction say. Nothing wrong with full length sizing to get started back up. Maybe just a smidgeon more turn after touching the ram.

My Hornady 10th Edition says that max case length is 2.540 and that trim length is 2.530. Consistency is the key, but that will come with practice.

The bullet type is going to determine the COL. We need to know what that bullet is before we can get to COL.

Load a few, shoot a few. It’ll come.

 

[Howa 9700]

Yes, first purchase was a new Lyman manual to replace Dad's old Lyman 45th. Updated for modern components, but otherwise, remarkably similar as far as process is concerned......with room for improvement.

Rifle is a Rem 700....in 270 win.

Bullets I have now are 140 gr Nosler partitions and partial box of Sierra Game King 130 gr.

Have primers, but no fresh powder. Looking for IMR 4350. In normal times, would be easy to find, but not today.

Long term, hope is to find an accurate combination of the 4350 and 130 gr Game Kings and stick with it.

If I was desperate, I'd go to GB and pay through the nose.......for the 4350 or a substitute, but not desperate yet, so willing to be patient for now. This is a long term project. Actually ahead of schedule on everything else. Figured it would take longer to accumulate all the missing parts than it did.

 

[jmorris]

I think the video method is just fine to a point, and, if fact, have used it. My problem is that it does not use a CBTO (OAL like a Hornady, etc) gauge to ensure you know the amount of shoulder set-back. If you get good results with it, great. Read no further. I just like repeatable results.

The reason I made the video is because many get caught up in some number of thousandths of an inch set back using tools that are new to them and they might not even be proficient using or even have standards to see if they are using them correctly.

The video above uses the specific rifle as a “standard” if you have the bolt falling half way home, on every case, you are not going to get much more repeatable results than that. A few thousandths either direction gives different results, even if one doesn’t have the ability to measure the change, it is easily seen that the bolt won’t close or falls freely home.

 

[NMexJim]