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Posted: 11/15/2008 10:46:42 AM EDT
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A standard RCBS shell holder measures .125". What do your Dillion shell plates measure?
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I checked a Lee and a RCBS and got the same.125. Never had any Dillion stuff except a swagger.
I can say that the 2/3 the way down case seperation has happened to me before using LC brass on about the third or fourth load. I think I can usually see which ones are going to seperate because there seems to be a color line that show up in that area of the case after cleaning and sizing from the last firing. Also I have had problems with cycling in ARs using IMR 4198 and no longer use it. Also there is a relaoding section on this board http://www.ar15.com/forums/forum.html?b=6&f=42 |
| Using the shellplate to control the amount of shoulder set-back is not the proper method. Don't worry about the shellplate thickness unless it prevents you from setting the shoulder back enough which doesn't appear to be your problem. The separations are caused from oversizing. An RCBS precision mic or some other case shoulder comparator should always be used. Setting the case shoulders back .003-.005 is plenty (any more is unnecessary) and then check several in the rifle just to make sure. I use an RCBS case mic. Dies can vary in the amount they will resize cases. Redding actually makes a set of shellholders for single stage presses to compensate for this. I tend to resize enough (.003-.005 setback) that there will be no odd case that may cause a jam. Cases "work harden" when fired and resized. Some cases will not resize as easily as others and this must taken into consideration when resizing to insure that ALL will chamber easily. The Precision Mic has definitely saved me some headaches. Hope this helps. |
| My 5.56mm shell plate is like using 4 different sized shell holders. .124" to .116" a variation of .008" The shoulder is pushed back to much, depending on what slot you used to adjust the FLRS die, causing excessive head space on firing, with case seperations. Yes a Shoulder Comparator or a case gauge would work , but an extra expense $$ that should not be needed. |
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You're not hearing what I am saying. Do not depend on die/shellholder contact for correct resizing/shoulder setback. Dies are different, just like your shellholder plate. Your rifle chamber's headspace may be on the long side and the die on the short side. You really have no idea how much you are sizing the brass. You must know the length of the fired case vs. the resized case.
You can continue to ruin your brass, or spend a little money on a gauge. The choice is yours, but you are dreaming if you think it's as simple as setting the press to cam over against the shellplate. There are too many variables for this method to work reliably and obviously it isn't working for you. The other end of resizing like this is a stuck round in the chamber because it was not sized enough. You should invest in and read a good reloading manual such as Sierra's. |
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As pointed out, unlike single shell holders that in the case of RCBS dies where you make the sizer touch the top of the single holder under tension to get the needed set back, the carrier plates for progressive presses use the top of tool plate for the case to pivot on, not the bottom of the carrier plate.
Here, you have to set the sizer against the bottom of the tool plate (not the carrier plate), and have to measure the needed set back for the cases to be sized against such. Bottom line is progressive presses are not as starting forward as a single stage press, and additional tools/equipments are need to be bought to set the units up (and keep them turned as the machines wear). P.S. Welcome to the site!!! |
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