When checking fired cases

[cw308]

When checking fired cases in the case gauge, the fired case had very little change. This is a new barrel, with the old barrel there was alot of expansion. Could the chamber be that tight that the case has very little stretch. I resize to just about zero headspace .001-2, neck size RCBS die, 12 times with this FC brass & still no sign of cracks, loose primers or hard chambering. I don't load hot 40.5, with IMR 4064 20 rounds slow fire per range trip, clean my brass to look like new before resizing. Now I'm cleaning the inside of the necks with the bore cleaner, Wipe-Out does a great job removing the carbon.

[mdmtj]

The case can't expand bigger than the chamber without breaking something.

[Brian Pfleuger]

Old barrel factory, new barrel custom? Most factory barrels are chambered near SAAMI maximum dimensions. Custom barrels tend to be closer to SAAMI minimum, which is what the case gauge is measuring.

[cw308]

Barrel is custom ( Rock Creek ) I could almost reload the fired cases except for the necks. My reloads are on the low side, so I was thinking it could of been that. At 200 yards it's a very accurate load for my rifle.

[Brian Pfleuger]

No surprise then. You've probably got a relatively tight chamber, combined with a load that doesn't fully expand the brass.

[Bart B.]

How can you resize fired cases with an RCBS neck sizing die that sets the shoulder back a couple thousandths?

That die doesn't touch the case shoulder at all when set to size all of the fired case neck down. Unless something's way out of kilter.

When you say "zero headspace" do you mean the case head's against the bolt face when the round's chambered and fired?

[T. O'Heir]

Cases do not have headspace. Headspace is a rifle manufacturing tolerance only.
Anyway, don't worry about how big your fired cases are. It doesn't matter.
"...40.5 with IMR 4064..." Out of what? .308? 40.5 is below minimum, but not by much, for all .308 bullet weights except those above 180 grains. Depending on what bullet weight you're using, this might explain the light case expansion. Still doesn't matter.
Below minimum loads can be as dangerous as above max loads. Causes weird pressures from the powder detonating vs burning. You're a couple of grains below. Not enough to worry too much about, but you need to work up the load for whatever bullet weight using a manual or Hodgdon's on-line data.
Regardless of what is happening now, you will have to FL resize your cases eventually.

[cw308]

T.O'heir the rifle is a 308 the bullet is a Sierra 168 gr. HPBT the case is Federal, the brass is a little thicker than most. Bart B, I measured the fired case with the Hornady case gauge, lets say it measures 1.629, I neck size, remeasured the case 1.627. The press is a RCBS Rock chucker, RCBS neck die screwed down till it hits the ram , then I screw the die down (1/8) cam over slightly & lock in place. Isn't that giving me .002 headspace or am I missing something. My run out is an average of .001 What am I doing wrong

[Bart B.]

CW, you're doing everything right; very right to get those results.

If the fired case dimension from head to shoulder with your gauge is 1.629", that means your chamber headspace is about 1.630" which I think's perfect for best accuracy and case life.

The distance from case head to shoulder reference has typically been called "case headspace" for decades. I'ts used by lots of people making and using reloading tools. Even SAAMI admits its used and is also meaningful, but it's not yet in their glossary. It equates to a headspace gauge with similar dimensions for a .308 Win; 1.630" GO, 1.634" NO-GO. The term's used to compare case dimensions to chamber dimensions with the same reference points; back end to shoulder reference diameter.

The space between the bolt face and case head on a chambered case has been called "head clearance" for much longer and that's what's in the SAAMI glossary of terms and definitions:

HEAD CLEARANCE
The distance between the head of a fully seated cartridge or shell and the face of the breech bolt when the action is in the closed position. Commonly confused with headspace.

HEADSPACE
The distance from the face of the closed breech of a firearm to the surface in the chamber on which the cartridge case seats.

HEADSPACE GAGE
A device used in a firearm to determine the distance between the breech face and the chamber surface on which the cartridge seats. Also called Breeching Plug.

I called that space between bolt face and case head "headspace" for years before a Remington field rep got me set right.

I'm curious as to how an RCBS neck sizing die can set a case shoulder back. Are you sure the die's a neck sizing and is so labeled that way? I've got two of them by RCBS for .308 Win and neither set case shoulders back in both my Rockchuckers.

[cw308]

Bart B Thanks again for the info. I will check the die after work a get back to you, but I'm sure it's a neck die only. Chris

[F. Guffey]

When checking fired cases in the case gauge,

cw308, you don't measure the length of the case from the head of the case to the datum/shoulder before firing? You don't measure the length of the case from the head of the case to the datum/shoulder after firing? You don't measure the length of the case from the head of the case to the shoulder/datum after sizing?

You do have a good tool that allows you to start using good habits with the Wilson case gage. The Wilson case gage has a datum the case sits on, from the datum to the low cut on the gage is minimum length/full length sized. The top of the gage down to the datum is go-gage length. I use a straight edge/pocket rule across the case head and feeler gages to measure the gap between the straight edge and the gage. I would use a height gage, I could use a flat surface like lay-out table, but the pocket rule works.

Could the chamber be that tight that the case has very little stretch. I resize to just about zero headspace

I could say the smith that cut the chamber should have include the length of the chamber from the datum to the bolt face in thousandths, problem, he did not know. To answer your question about how tight your chamber is, 'I do not know' you started measuring in the middle, you did not start measuring until the case was fired. You did not measure after sizing.

the feeler gage: The feeler gage is a standard, it is a transfer, and it is a tool that is used to verify.

Back to 'the case has head space because Bart B. insist it does', it does not have head space, the case has a length, the length is easy to keep up with if the reloader understands the datum is not a line, the datum is a round hole. The datum for the 308 W is .400", the datum for the 30/06 is .375". SAAMI does not list head space for the case, SAAMI list a length from the datum (round hole) to the head of the case.

And before someone says something about all you got to do is go to a hardware store to purchase a bushing, listen to me, the bushing will have a radius, the datum does not have a radius.

In the world or reloading everything is a head space gage. With good habits the reloader can move to comparators. Measure the length of the case from the datum to the head of the case before firing, measure the case again after firing then compare. Then size the case and compare the length of the sized case with the fired case. All of that without saying and or typing head space.

Problem, finding a comparator, I make comparators, not commercial enough to sell, the Wilson case gage datum has a radius.

F. Guffey

[Bart B.]

Guffey, I think your info "The top of the gage down to the datum is go-gage length." is weak in being correct on the Wilson gauge steps. Its instructions state:

The head should not be below the lower step nor above the upper step. Ideal length for a properly headspaced rifle should be half way between or slightly closer to the upper step.

That's based on the steps on the gauge being relative to SAAMI spec chamber headspace. So, the upper step (top) of the gage to the datum is NO-GO gauge length; 1.634". GO gauge length is the shortest measurement; from the lower step of the gauge's case head end is 1.630" from the datum.

My Forster GO headspace drops in one and its head is perfectly even with the lower step.

[F. Guffey]

Bart B. I can not help you, there was a time I took up other causes, I can not recall anyone being better off after I finished.

I will call Forster at your request. the first thing I will do is ask for your money to be returned.

You do not have a straight edge, you do not have a feeler gage. The go-gage is a standard, it is a transfer, I am the fan of transfers and standards. The Wilson case gage is not a drop-in gage, but for years reloaders have treated the tool like a tool that is nice to have. The OP has a case gage, I suggest he learn to use it.

The Wilson case gage has a datum, the datum in the Wilson case gage has a radius. If a reloader can measure the length of the go-gage from the datum to the gage head the same reloader can use the go-gage to check the accuracy of a case holder and die or the accuracy of a case gage.

F. Guffey

[F. Guffey]

The head should not be below the lower step nor above the upper step. Ideal length for a properly headspaced rifle should be half way between or slightly closer to the upper step.

The bottom step is minimum length, the top steep is go-gage length. The case instructions instruct the user the case should not be shorter than minimum length or longer than go-gage length. I did not write the instructions, I am the one that measures the length of the chamber from the datum to the bolt face because I am the one that can, after determining the length of the chamber I do not need all those gages. I have them, I can use them, I have instructions, I can understand the instructions.

Reloaders and assuming: The instructions assume the reloader know the length of the chamber, the PO could have measured the length of the fired case from the datum to the case head. The instructions assume in the perfect world the chamber is go gage length.

Half way between? For the 308 W add .002" to minimum length, for go-gage length subtract .002"

For the 30/06 change the .002" to .0025". But then there is a problem, I have one chamber that is .016" longer than a minimum length chamber meaning when I check a fired case in the Wilson case gage the case head protrudes above the gage .011".

F. Guffey

[cw308]

Bart B, My neck die is marked ( RCBS 308 WIN NECK 6 ) the part # 15502 . The shell holder is # 3 . Resizing F/S or NECK I set the press up the some way with fired formed cases & all measurements are the same on both

[Bart B.]

Both of my RCBS .308 neck sizing dies' (dated 1966 and 1971) shoulders stopped about 1/10th inch short of sizing fired case necks all the way back to the shoulder when new. There' was about 1/10th inch space between the case shoulder and die shoulder with the shellholder hard against the die's bottoms. Their necks were lapped out to .331 and .333" so their expander ball didn't need to be used.

I ground about 1/10th inch off the bottom of the one dated "66" so I could size case necks all the way to the shoulder back in the late '60's when I thought neck sizing was the cat's pajamas. The die was set in the press to stop about 1/50th inch short of touching the fired case shoulder. If this die's set to touch the shellholder when sizing fired cases, it sets their shoulder back to make case headspace about 1.625" which is a bit less than SAAMI spec and about .005" less than my fired case headspace. I never altered the '71 die.

So, if your neck die's dated later than mine, maybe RCBS made the die's headspace shorter then. Did you get that die new?

[F. Guffey]

Both of my RCBS .308 neck sizing dies' (dated 1966 and 1971) shoulders stopped about 1/10th inch short of sizing fired case necks all the way back to the shoulder when new.

1/10 of an inch or .100"? That would be enough to center the case in the chamber. Then you made a wild guestimate of .050" when backing the die off the shell holder.

.100" is 1/3 of the neck meaning before you ground the bottom of the die 2/3 of the neck was not being sized. Back then a reloader could do better than that by adjusting the sizing die off the shell holder with a feeler gage. and it was possible to determine how much to grind.

Not fair, RCBS mad two different neck sizing dies that were different and did not change the numbers.

I have always contended grinding a die is a bad habit. Grinding the bottom of a die with no clue, just a guestimate of 'where to stop'.

F. Guffey

[cw308]

Bart B, The dies were purchased new 2003. What's your feeling on cleaning the inside of the necks with a bore carbon cleaner. Would it cause any problem to the brass? I used a cleaner called Wipe-Out, did a nice job on cleaning, I then wrap a piece of 0000 steel wool on a pencil point to shine the inside, I think it keeps run out to a minimum. I'm thinking of going back to full sizing after following your posts. I reload with the standard RCBS dies, I don't neck turn the brass. I shine the neck,shoulder & head area with 0000 wool to check for marks after firing. My way of following on whats going on. Thanks for all your help. Chris

[cw308]

After looking over the posts a few things come to mind. "He who can't reload corrects spelling and grammatical errors" It is true that I'm not a master of the English langauge and I might make errors in grammar and spelling, BUT I went on this site for information and help and to share my reloading information. Thank you guys who gave information freely without cheap shots. Chris

[F. Guffey]

"He who can't reload corrects spelling and grammatical errors"

Blame it on typing, my wife used my computer and complained about the keys being worn to the point she could not read them. I suggested she use a spare keyboard I have under the desk, just reach under the desk to find the location.

F. Guffey

[Bart B.]

cw, you can clean the inside of your dies with bore cleaner as well as naphtha and other metal cleaners such as carborator cleaner. I don't know what bore carbon cleaner is. Flitz metal polish is great to keep the die's insides smooth but clean out its residue before sizing.

Clean and smooth die insides do little to keep case necks straight. A really smooth expander ball and the inside of case necks helps. Sized case necks are straightest coming out of full length sizing dies whose neck is a couple thousandths less than cartridge neck diameter and no expander ball is used. They're the only die type whose neck sizing surface is perfectly aligned with the shoulder and body sizing surfaces. Decap primers before cleaning fired cases.

[Jim243]

Thank you guys who gave information freely without cheap shots. Chris

Bart & Guffey, here I thought you guys were going soft (LOL). Cheap shots are their middle names. (LOL)

But seriously, CW it sounds like you do not tumble your cases before sizing. This is a practice that many others do not do as well. The one downside to this practice is that it can scratch the inside of the die and then leave marks on the cases when sized.

It might sound like you clean your cases manually by hand with steel wool, I would suggest you change over to a non steel dueby pad used for dish washing, it is a little less abrasive and will get the cases clean as well.

Most of any build up inside the dies is from the lube you use for your cases. This can be removed by using just hot water/soap and any nylon brush (baby bottle brush) to scrub the inside of the dies. Be sure to dry and put a drop of oil (Rem oil) inside the dies to insure they do not rust.

Using a copper bore brush on the inside of the case mouth to clean the neck is OK, but Lyman, RCBS and others make nylon ones that work as well and will not scratch the inside of the case or accelerate split necks.

These are just suggestions and not hard and fast rules, and each of us have to make due with what we have.

But, if you get an opportunity to get a tumbler and media to clean the cases your reloading will get easier and go faster.

Just a suggestion.
Jim

[cw308]

Jim243, I do tumble the brass with corn cob media. I manually clean the in & outside of the case first before tumbleing. After sizing, if you have to trim your brass down,do you run it through the die again?

[F. Guffey]

After sizing, if you have to trim your brass down do you run it through the die again?

I suggest tumnblng again after sizing. Most trim before sizing,

F. Guffey

[cw308]

F. Guffey, I clean my brass after sizing. I also trim after sizing, are you sure you trim before you size.