Headspace/Chambering woes

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Yesterday, 09:38 PM #21
nofishbob
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Join Date: April 16, 2008
Location: Copper Canyon, TX
Posts: 372 One more small piece of data:

The re-sized, once fired cases are about 0.004" bigger at the case web area than an unfired case.

The primer pockets are still tight as I test-primed a few and the insertion force seemed normal.

Bob
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The re-sized, once fired case is larger?

#17
fguffey
Member


Join Date: August 28, 2008
Posts: 1,404 Your rifle was not test fired with the scope, mount and rings installed. The mount was installed after test firing,

Grinding the bottom of the die, I have always insisted grinding the bottom of the die and or top of the shell holder is not necessary. Now that you have ‘fixed the die’ there is hope. I am forming cases for a wildcat that requires shortening a 300 Win Mag forming die .156”. All I have to keep up with is the .156” I removed, I can adjust the die off the shell holder .156” and continue using the die for 300 Win Mag.

Back to my favorite forming dies, the 308 W, 7MM08 and the 243 Winchester, all I have to keep up with is the distance I adjust the dies off the shell holder like the 7.7 Japanese from 30/06, I adjust the die off the shell holder .076” or the 8mm57 from 30/06, I adjust the die off the shell holder .121, and yes, I have an 8mm57 forming die.

F. Guffey




When sizing a case the case has case support, except, when the die is shortened, when the top of the case is being sized the unsupported bottom of the case is allowed to bulge/squat.

Back to ‘no one measures’ without knowing the diameter of the case above the web before firing measuring the diameter afterwards is of little value. A .004” upset at the web would be all the warning a reloader would get.

F. Guffey
 
Well, I got the Wilson case gage this afternoon and have a better idea of what is happening.

First, a factory, unfired, case fits the case gage perfectly, and chambers and extracts from the rifle with no problem. No surprises here, but nice to confirm.

A case over-re-sized with my ground re-sizing die falls way too far into the case gage, by about the same amount I ground off the bottom of the die. I guess that this is no coincidence.

These cases will chamber with some difficulty, and then require a solid rap on the bolt handle to extract. Using finger pressure, they also stick in the gage.

Somehow, the re-sized cases are just the wrong shape.

With the fear that the over re-sized cases were distorted by pushing them too far into the die, or that the expander pulled the neck back, I re-sized a few with the die screwed back as close as I could to the original position, and with the expander removed.

These cases also fit in the case gage, and stuck there when pushed, and would not chamber in the rifle.

It seems reasonable to think that the internal shape of my re-sizing die is wrong. If it is I sure learned a lesson about needing case gages.

I expect to receive another re-sizer Monday, but it may not be until Friday that I can test it.

An interesting thing I learned with the case gage is that the once-fired brass I have been using is darn close to fitting in the gage without sizing. It looks like about 0.002" average beyond max. With no experience I thought that they would be worse.

Bob
 
glade too see your getting the whole sizeing thing down, but FYI on the scope base screws , scope ring bases for Savage's come with longer screws for the rear base and shorter screws for the front , so no grinding needed just put them in the right holes, , :)
 
savanahsdad-

These were installed by Savage. The required grinding was about 0.010".

I won't give them the benefit of the doubt again, it will be the first thing I check.

Bob
 
I helped out in a sports shop years back , and the gunsmith there did the same thing more than time or two , that's where I learned that from ,
 
Well that was easy.

I unexpectedly received the new RCBS sizing die a little while ago. So much for USPS tracking info.

Cleaned the die, installed it in the press, ran a lubed case into it. Now to test it!

Case gage: Perfect.

Rifle: Perfect.

No further drama, my problem was just an out of spec sizing die. I have had great luck with Lee dies and accessories in the past, and I will still buy from them, with just a little less enthusiasm.

Thanks to all who helped me with this problem! Now I can try to get back to where I thought I was last week!

Bob
 
Glad to hear you got it sorted out. There is a take away from this somewhere about finding where the cases are dragging. You had mentioned that it appeared it was the shoulder but clearly that isn't the case. So I wonder where it might be and how best to find it?

BTW, I would have no reservations about sending that die back to Lee. Even if you hadn't ground on it, they couldn't have put back the metal wherever they had removed too much.
 
...It seems reasonable to think that the internal shape of my re-sizing die is wrong. If it is I sure learned a lesson about needing case gages.

Caution: Many, if not most, case gauges are cut to measure head to shoulder datum dimension only, not diameters. In fact, the LE Wilson instructions note that they use oversized reamers on purpose, so that there is no interference with measuring that dimension.

It is possible to get a "reamer-cut" case gauge, made to imitate a rifle's chamber.

But most case gauges aren't cut the same as a chamber, so use them for their intended purpose and nothing more... :)
 
Thanks dmazur-

What you say is certainly correct in this case-the SHAPE of the re-sized case was not verified by the case gage.

All the gage told me was whether or not the case head to shoulder distance was correct or not.

On my over re-sized cases this dimension was way under spec, yet the case still would not chamber correctly.

If I had to guess, I would say that the radius of the shoulder to case body transition is too large on the Lee die. The factory and RCBS-sized cases have a much more sharply defined transition than the Lee re-sized cases.

Oh well- I learned a lot and only ruined about 12 cases in this exercise.

Bob
 
A Lee die made wrong? Wow never saw that one coming. If you're willing to pay shipping and deal with their rude customer service they'll fix it for you.
 
When the carbide shattered in my sizing die on the first use they acted like I was lying about it and wanted me to pay shipping to get it repaired.
 
I second JohnM, I have lots of Lee Equipment and have only needed to call them a couple of times but they have been absolutely great. Guess you just caught someone on a bad day or something.
 
Not sure those cases are ruined just yet. A little cream of wheat, a little fast powder and a little reading and you should be able to fire form them back to your chamber.
 
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