I have checked a number of FL dies that measure about half way between SAAMI GO and NO GO dimensions. So some of the issue is in the FL die proving that knowing the actual SAAMI dimensions can be beneficial.
Anybody ever had to have a resizing die ground shorter?
- Thread starter Lefty Trigger
- Start date
dcali
Bullet Maker
That's with the die touching the shell holder, I assume?
Yes when I check a die like that I use a shell holder that is exactly .125 deep and it is set hard against the bottom of the die in my Rockchucker press.
My Stoney Point gage is set to the exact length on a Forster gunsmith gage. This is fairly accurate since the length of the sized case only requires a few thousandths travel from my caliper jaw.
I usually size a commercial case that has to have the shoulder pushed back. The case is sized 3 to 7 or 10 times until I am sure I cannot make the shoulder move any more. I may apply lube more than once to insure the case can slip upward into the die as far as possible. I prefer commercial brass because it usually is range pickups and has not been fired in a machine gun. Badly over size brass will stretch my press about .002 on the first sizing. Subsequent sizing passes get rid of the stretched press stress.
I measure the case and mark it with a permanent marker and save the "gage case" in the die box with the dies. The data has been recorded in a spreadsheet.
This becomes an interesting exercise for me when I have 4 or 5 rifles in the same caliber or if I have 4 or 5 sets of dies in the same caliber.
With this information it is easy to take a fired case from a new to me rifle and set up a previously measured FL die.
Using these tools I have found a number of dies that are out of spec to SAAMI standards. You will also find that FL dies are more consistent than rifle chambers.
My Stoney Point gage is set to the exact length on a Forster gunsmith gage. This is fairly accurate since the length of the sized case only requires a few thousandths travel from my caliper jaw.
I usually size a commercial case that has to have the shoulder pushed back. The case is sized 3 to 7 or 10 times until I am sure I cannot make the shoulder move any more. I may apply lube more than once to insure the case can slip upward into the die as far as possible. I prefer commercial brass because it usually is range pickups and has not been fired in a machine gun. Badly over size brass will stretch my press about .002 on the first sizing. Subsequent sizing passes get rid of the stretched press stress.
I measure the case and mark it with a permanent marker and save the "gage case" in the die box with the dies. The data has been recorded in a spreadsheet.
This becomes an interesting exercise for me when I have 4 or 5 rifles in the same caliber or if I have 4 or 5 sets of dies in the same caliber.
With this information it is easy to take a fired case from a new to me rifle and set up a previously measured FL die.
Using these tools I have found a number of dies that are out of spec to SAAMI standards. You will also find that FL dies are more consistent than rifle chambers.
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Why not grind .020 off of the top of the shell holder? That is what I did.
If you grind .020" off the bottom of a die, your die most likely will not be in spec in the case base area. You have bump issues now, wait till the case wont chamber because now the diameter is too great at the base, the rodeo gets more intense.
I spent 3 hours yesterday base sizing XC brass that was fired in a puffed chamber, just so it will feed in a new chamber, for me this should be a one time ordeal.
divingin
Gold $$ Contributor
Does that make sense? You're eliminating interference between the die and shell holder to allow the die to go further down (alternatively: to resize more.) I don't see how it matters where the clearance comes from; the case is going to go further into the die either way, isn't it?
Across all 8 of my 308 Win full length sizing dies, they all headspace .004" to .005" less than a GO chamber headspace gauge at 1.630". That's with a shell holder measured .1250" deck height. Feeler gauges those sizes slip fit between die and shellholder with GO headspace gauge tight in die.
Asked both RCBS and Forster about that; both said that ensures complete sizing that makes case headspace end up a few thousandths short of a minimum spec chamber headspace.
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I've shortened dies before, just hand sanding on a piece of emery cloth sitting on a flat surface (mirror). Make a nice figure 8 pattern, rotate the die in your hand often so it doesn't take material off unevenly. Reminder to clean the die extremely well to remove all the residual grit before you try to use it.
You're not going to decrease sizing at the base of the case, since most often what you're removing is part of the chamfer which doesn't size the case anyway.
You're not going to decrease sizing at the base of the case, since most often what you're removing is part of the chamfer which doesn't size the case anyway.
I am not surprised by your findings because that is about how I would design production quality dies. I have found a few sets even shorter but I have no idea why RCBS would ship dies that are .002 to .003 longer than the go gage as a number of mine are.
Brians356
Silver $$ Contributor
Shell holders are quite inexpensive compared to good dies. I would engrave the modified shell holder "MOD" or "30-06" to warn future owners and inform archeologists.
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Brians356
Silver $$ Contributor
Cases don't have headspace, but they can produce headspace.
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When I spun a new 22-250 barrel onto my Savage model 12, I had the same problem. RCBS die would not move the shoulder back at all and brass was a tight fit in the chamber after FL sizing and loading. In my mind the possible fixes were:
1 Grind the bottom of the die a bit
2 Grind the shell holder
3 Loosen the barrel nut and back the barrel out a smidgen as I had obviously installed it a bit on the tight side of the SAMMI spec.
I chose number 3.
1 Grind the bottom of the die a bit
2 Grind the shell holder
3 Loosen the barrel nut and back the barrel out a smidgen as I had obviously installed it a bit on the tight side of the SAMMI spec.
I chose number 3.
Ledd Slinger
Silver $$ Contributor
If everyone would just realize how amazing Savage rifles are the world would be a better place 
... Lol. 
... Lol. We know. That is why I bought my last one about 40 years ago. I called the factory to price a new barrel and they were on strike.
If everyone would just realize how amazing Savage rifles are the world would be a better place
Please explain how a case produces headspace.
Tried to, but cannot figure out how that's done
ttfreestyle
Silver $$ Contributor
O nooooooo!! Here we go with that word again!
Because a horse is a horse is a horse of course
Well, there is in fact a method that produces the same end result without the need to alter either the die or shell holder.
Simply screwing the decapping stem/pin up into the die and placing the correct thickness feeler gauge between the case head and shell holder bottom will raise the case far enough to get the desired bump.
Have done this numerous times when I’ve been gifted once fired brass from another’s rifle that doesn’t handload and they wouldn’t chamber in my rifle.
If, in the case of my custom 375 Weatherby, the chamber is a tight match chamber with minimal spec headspace, then I measure the difference between fired cases and a sized case that is too long, then turn that amount off the TOP of the shell holder...job done. More often, a .010” skim is all that’s necessary and normal die adjustment gets the desired bump.
Cheers.
Simply screwing the decapping stem/pin up into the die and placing the correct thickness feeler gauge between the case head and shell holder bottom will raise the case far enough to get the desired bump.
Have done this numerous times when I’ve been gifted once fired brass from another’s rifle that doesn’t handload and they wouldn’t chamber in my rifle.
If, in the case of my custom 375 Weatherby, the chamber is a tight match chamber with minimal spec headspace, then I measure the difference between fired cases and a sized case that is too long, then turn that amount off the TOP of the shell holder...job done. More often, a .010” skim is all that’s necessary and normal die adjustment gets the desired bump.
Cheers.
You are sure the issue is with the die? Here is why I ask. Did you try and chamber a spent cartridge case before you resized it?
This is a drawing of a 308 Winchester case and chamber. I only assume 308 Winchester as the 243 Winchester, 7mm-08 Remington and the 260 Remington all have the same case head to shoulder datum. The MAXIMUM CARTRIDGE dimension is 1.634" -0.007" so 1.627" to 1.634". The Hornady case gauge is a comparator type gauge and that is as good as it gets. I really doubt your number of 1.622" is a real true measurement value. The point here is a normal resizing die will typically resize a 308 Winchester case to 1.630" or 1.629" which is also what I measure on most factory ammunition. The Minimum Chamber headspace dimension is 1.630" with 1.634" being a typical No/Go gauge and 1.638 being a typical field gauge.
Let's take a look at a Hornady case gauge.
With the gauge setup and zeroed we measure a known actual 1.630" headspace gauge.
The gauge is reading 1.624 which is -0.006" of nominal. The problem is the hole on the bushing is not a sharp corner break hole but a slight radius and not a true 0.400" where it meets the case. So what happens if you have a really tight chamber of 1.630" or even slightly less? With a normal shell holder of 0.125" and a correctly setup sizing die the case will typically set up to a 1.629" to 1.630" case head to shoulder datum and that is as good as it gets and is not a problem with the die or shell holder. Yes, we can grind the shell holder down and resize the case to below SAAMI specifications but as designed, looking at the drawing, any properly resized case should chamber in any chamber within specifications.
<Edit> and this is where the lights went out. </EDIT>
What happens is if your case actual dimension is 1.630 or less all the sizing won't matter. Yes, you can remove material from your shell holder but you will be taking a case already sized to specification and making the head to shoulder datum less, that is about it. I would try a resized case and see if it chambers before worrying about grinding a shell holder.
Generator running so things are semi normal.
Ron
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