Cases Fitting Too Tight

[MEHavey]

Let's do a little (relative) headspace measuring po'boy-style:

QUESTION-1: Do you have a digital caliber?

If the answer is yes, then QUESTION-2: Do you have a 9mm case, or a 38sp case, or a .357Mag case?

If the answer is still yes, then QUESTION-3: Do you have (1) a case successfully fired in your rifle? (and as yet unsized?)

If the answer is still yes again, then put one of the empty pistol cases over the mouth of the mouth of the fired rifle case and measure the total length with the caliper.

Then put that same pistol case over the mouth of a case that has been sized but will NOT chamber ...and measure total length again.

What are the two measurements?

If you have an unfired commercial round, measure that one the same way. What is that measurement?

 

[Muttt]

Slamfire,

So why not just keep the shell holder in the box with your dies??? Kind makes it hard to forget to use that shellholder with that set of dies. I would rather grind away all of a RCBS shellholder than do anything adverse to a set of Redding dies. The dies aren't the problem. The shellholder is too thick and doesn't allow the die to get close enough to completely resize the case. You ever notice those shellholders they sell that are different thicknesses?? Same principle. But, why buy a set of six when you only need to adjust one.

 

[wankerjake]

If the answer is still yes, then QUESTION-3: Do you have (1) a case successfully fired in your rifle? (and as yet unsized?)

If the answer is still yes again, then put one of the empty pistol cases over the mouth of the mouth of the fired rifle case and measure the total length with the caliper.

Then put that same pistol case over the mouth of a case that has been sized but will NOT chamber ...and measure total length again.

Case that fits tight: 2.837"
Case fired from my rifle, unsized: 2.836"
Winchester factory round: 2.828"

Measurements for the two are the same. Keep in mind the case will chamber, but I have to crank on it pretty hard. Basically I don't want to risk a stuck case.

 

[wankerjake]

Other measurements:

OAL of all 3 cases: 2.034"

Base to shoulder:
tight case: 1.550"
case fire in my rifle: 1.550"
factory case: 1.550"

Base to where neck meets shoulder:
Tight case: 1.814"
Case fired in my rifle: 1.794"
Factory case: 1.794"

So here is some variation, although it is hard to tell exactly where the shoulder ends and neck begins so it may be a little arbitrary. Still it looks like the tight case has a longer shoulder on the order of ~ 0.02" May be a little less due to my error in guestimating, but I don't think it's more.

I have some brass I know to be once fired from another rifle. I tried some in my rifle and it fits tight, although not bad. I resized it and it's still tight. I would still shoot it, it's not as tight as the other stuff. I'd say my chamber is just a hair smaller than what the tight cases were shot in, and the die isn't bumping the shoulder back far enough so once they get a certain length I'm done. So I reckon I could shave off a little shell plate until it resolves and that will be my shell plate, or just toss the tight stuff or try it in another rifle. My little bro just bought a rifle, I'll be sure and test some brass in his rifle. Maybe he can use it.

 

[fguffey]

Slamfire 1, forgive, before grinding the die and or shell holder determine if gringing either is going to help, place the feeler gage between the deck of the shell holder and head of the case, doing so will raise the case, without grinding and or purchasing Redding competition dies, then if it works, the amount of material to be removed will be verified by the feeler gage., agaion when chambering a rifle I start with a short chamber, it is not possible to accomplish this technique without a large outlay of money in tools, I do it all with a $ 11.00 feeler gage.

F. Guffey

 

[fguffey]

Mutt, "The shell holder was too thick" and you have/had no way to measure the deck height of the shell holder, before and or after? All of my shell holders have a deck height of .125, I can reduce that by .011 thousands when using an RCBS shell holder, .017 with most of my Lee shell holders and for the better fitting Herters, .002.

"Oh, I was using RCBS shell holders and Redding Dies. I suppose that's were the problem was coming from, Different specs for different manufacturers"
Keeping up with two things at the same time, reducing the deck height of the shell holder reduces the length of the case from the head of the case to it's shoulder when sizing, some claim it turn the die/shell holder into a small base die. rthose that say that have trouble measuring either.



The deck height of the shell holder is .125 thousands, call RCBS, call Redding, call Lee, tell them you have one of there shell holders that has a deck height of .120 thousands. They will tell you that is the difference between a minimum length, full size, store bought, commercial case when compared to the perfect (go-gage) length chamber, RCBS will offer to exchange it.



You measured the case, I do not know how or what tool you used but if you removed metal from the top of the shell holder and or bottom of the die or both you shortened the case from the head of the case to it's shoulder, if the case diameter was too large when chambered the chamber would have imprinted on the case, with out the black marker or soot.



The OP said he used a black felt marker to blacken the case then chambered and found evidence the shoulder of the case had an interference fit with the shoulder of the chamber.



Again, reducing the deck height without knowing the deck height, to me, makes no sense, If it is required to alter a die and or shell holder the minimum amount of information necessary should be, How much metal removal is required? How does the ginger know when to stop grinding? A dial caliper or depth micrometer can be used to determine deck height before and after grinding.



As to the shell holder holding the case off and not allowing the case to be sized, measuring before and after? Normal expansion of the case head with new factory commercial loads is is less than the numbers you listed by 5 times, you are exceeding the maximum recommended load or the chamber diameter is too large, not the shell holder or dies's fault, but reducing the deck height of the shell holder reduced the length of the case, and depending on where you measure the case head, the shell holder prevents the first .125 to be sized plus the radius on the mouth of the die, and there is a radius on the chamber.

F. Guffey

 

[MEHavey]

Case that fits tight: 2.837"
Case fired from my rifle, unsized: 2.836"
Winchester factory round: 2.828"

OK. You have the answer. Assuming you really have bottomed the die against the ram/shellholder, you have to relieve the shell holder until the (newly)-sized cases measure ~2.828" (i.e., the factory round) with this system of *relative* headspace determination.

You can then back the die off to something like 2.834" (0,002" under) for your chamber for first firing. Neck size only after that.

 

[fguffey]

The deference in case length between the 30/06 and 308 W from the head of the case to the shoulder is .388, I form 308 W cases from 30/06 cases with a forming die from start to finish the shoulder on the 30/06 is moved back .388 thousands, while it is being formed the shoulder passes the 7.7 Japanese, 8mm57 and 7.65mm53 BM,

When forming cases I form the cases to fit the chamber, again I do not fire to form, I form first, it is no secret, it is about knowing when to quit forming, and, it helps to know how to measure the length of the case from the head of the case to it's shoulder. There are a lot of tools available, there are a lot of adapter kits available all nice to have but not necessary, nice to have is expensive, not necessary is free.

When determining chamber length for the 30/06 family of chambers I use the 280 Remington case, the shoulder is ahead of the 30/06 shoulder by .051 thousands, most have no trouble moving the shoulder forward, by firing, For me it makes more sense to move the shoulder back, even if the formed case is never loaded and fired the reloader, after forming a case to fit, knows the length of the chamber from the bolt face to the shoulder of the chamber.

F. Guffey

 

[wankerjake]

So I pulled the few bullets I had laoded that were tight, re-adjusted the die to 1/8-1/4 turn deeper than the ram, pulled the primer stem up and re-sized. This worked with the 3 shells that were tight.

I believe this was my downfall and if anybody cares, I fixed the problem. This quote is from my first post. Since I had pulled loaded rounds, to re-size I didn't want to punch out the primers so I adjusted my de-priming stem up out of the way. When I put it back I think I put it down too far. I THINK this was bottoming out on the inside of the shell and not allowing the shell to go into the die far enough.

I noticed this tonight as I was sizing/de-priming some brass that the pin was bent. I remember it happening awhile back and being thrifty I just straightened out the pin with pliers and kept going. Tonight I decide "hey, RCBS gave me a bunch of pins for free, how about I just change it?" So I did, and as I thought the de-priming stem was a little too long before so I shortened it noticeably. Then I though I better run a couple of those shells thru to see if that would help and I'll be darned if it did. I could feel right away the shoulder push back and they fit with ease now. So that's that, and I'm all loaded up and ready for deer season!