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Speaking of Murphy's Law, a friend's cousin Capt. Edward A. Murphy is the person whom is credited with coining the law and who's name it came from.
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07-15-2015 07:52 PM
# ADS
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FL reloading die tolerances cause some variation in the diameter of the sized case body.
I check the body diameter in two places by FL sizing cases and then measuring the case diameters.
1. Bright pressure ring at the junction of the solid case head and the case walls.
2. About .030" back of the shoulder corner.
At the shoulder dia. At the pressure ring
The Lyman FL measures .423 .466
The RCBS trim measures .428 .467
One RCBS FL Measures .430 .465
One RCBS FL measures .425 .466
The Lee FL measures .425 .466
The Pacific FL measures .425 .466
The CH trim measures .426 .467
As you can see the diameters are pretty consistent. Most of the variability was covered in my previous post that discussed the headspace dimensions.
Based on the numbers above I would expect the Lyman FL die to require the greatest sizing force.
The least sizing force should be either the RCBS trim die or the RCBS FL die with the .430 shoulder. This is debateable though because this RCBS die also has the smallest base dia.
Anyway this data is offered as food for thought.
I once had 4 sets of Lyman dies that I bought for the old PA (precision alignment) seaters. Everyone of the FL dies too more force than my original die sets to FL size a case.
These were late 1960s Lyman dies. I mention this because you had a case rim pull off. Verify that you have a good fit in your shell holder because the 7.65 rim is a little different than the common .30-06 size unless you are actually using .30-06 brass. Be sure to clean any new size out and use plenty of lube on the first case and size it in 1/4" increments relubing the case with your fingers until the first case is completely sized. Be careful with the first 4 or 4 cases in a new die.
The surface finish and Rockwell hardness of the die also affects the force required to size a case
I have found that polishing a new die with 400 to 600 grit wet or dry silicon carbide paper used wet with a light oil produces a superior internal finish and reduces the sizing forces required. I do this polishing in a lathe so it might not be possible to duplicate the precision polishing by hand without damaging the die.
Cases that have been tumbled to the bright jewelry finish are also easier to size.

Originally Posted by
mrappe
One case worked in the Lyman Die but the case was not going al of the way into it. The next case got stuck in the die and when I tried to lower the ram the case rim sheared off. I had to dig the case out and the expander's threaded rod got bent. It looks like I will need to turn the outside of the neck to get it to work. I ordered a Forester hand held neck turning tool since they were the only one that I could find with a 311 mandrel for.
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I just got a RCBS die for the 6.65 Arg and it seems to do the trick. Now my chamber easily.
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Originally Posted by
mrappe
I just got a RCBS die for the 6.65 Arg and it seems to do the trick.
And there you go! Once again we find RCBS doing the trick...(7.65 though, not 6.65)
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