[F. Guffey]

Unread Yesterday, 07:31 PM #1
flyguy958
Senior Member


Join Date: June 27, 2009
Location: SC
Posts: 121 Case Thinning (Too Much?)

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How much case thinning at the head is too much? I've cut 3 cases in half that I can "feel" a groove with a paper clip. I can feel a difference in each. The worst is at the top and is also the one that separated.
Load data:30/06, CCI Primer, IMR 4350-56.5gr, 150 Barnes TXS, 3.280" OAL.
These have been full length sized twice and neck sized three times for a total of 5 reloads.


Unread Today, 02:02 PM #4
TATER
Senior Member


Join Date: November 19, 2002
Location: Mississippi
Posts: 593 F.Guffy, For my interest alone, Are you saying that I am wrong. Or just that I did not go deep enough. With this question, I am assuming the OP is kind of new.
I understand that head space is not an issue as long as YOU know what you have and account for it..
TATER is online now


Tater, forgive, I did not critique your response, The OP neck full length after 2 firings and neck sized after 3 firings sized, is there is nothing between neck sizing and full length sizing? The Internet is full of it, fire to form then neck size 5 times after each firing ‘THEN!!!!’ full length size to restore the case to minimum length. and again I ask “HOW is that possible to restore the case and start over? The case has been fired 7 times, the OP has reloaded his cases 5 times with the beginning of case head separation, his cases have been fired 6 times. One more time, I am the fan of cutting down on all that case travel. I off set case travel with the length of the case from the shoulder of the case and head of the case.

And, we do not know what rifle he is using, standards, I am the fan of standards, I do not apply the same standards to all receivers. There is a long boring story that starts with the firing pin strikes the primer, then the case, powder and bullet runs to the front of the chamber etc., on and on etc.. again, that story does not apply to all receivers, then there is Hatcher, someone handed him the wrong rifle, they did not hand him the 03 Springfield he thought they handed him. Hatcher assumed all receivers behaved alike, all Hatcher that would have been necessary to understand why his experiment did not work was to mark/scribe the case before firing, had he marked/scribed the case he would have found he was wrong, not for all Springfields, he was wrong about the rifles he was testing. The shoulder was moved forward .080”, we all know that a case will not stretch .080” between the case body and case head, Hatcher assumed that is what would happen, instead his shoulder was erased and became part of the case body and part of the neck became part of the shoulder, again, had he scribed the case body/shoulder juncture before firing he would have been able to ‘figure’ that out.

Add:

Unread Yesterday, 05:06 PM #5
flyguy958
Senior Member


Join Date: June 27, 2009
Location: SC
Posts: 122 Not new, been doing this a while but with a lot to learn. This is a Winchester model 670 bolt gun. I was surprised at the difference in thinning of the cases. Out of 15 cases that have all been through the same loads, 8 have thinning I can feel the rest don't. Just wondered what other find.
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You can have your own opinion but you can't make up your own facts !
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“but you can't make up your own facts !” I have no clue what press and dies your are using, I do not know if you can determine if the cases are being sized when the ram is raised. I have (3) presses that are guaranteed not to flex, when using the rest of my presses I can determine if the case whipped the press or if my press had the ability to overcome the case's ability to resist sizing. Back to fire forming, then neck sizing 4 times then return the case to minimum length by full length sizing, added with the old saying a case is not fully grown until it has been fired 5 times, then when added to ‘work hardening’ while sizing and firing etc., etc.. I apply the ‘leaver policy’ I leave-er the way I found-er.

For me a good start is forming, I form cases to fit first, then fire, because I measure before and again after I compare the difference in length between the formed case and fired case, there is no excuse for a spread or difference in length. Again, I am the fan of cutting down on case travel. My favorite cases, cases that have been fired in trashy old chambers, for the 30/06 chamber my favorite case is the 280 Remington case. The 280 Remington case is a ‘can not miss’ case for off setting the length of any 30/06 chamber, I use the 280 Remington case to off set the length of a chamber that is longer between the shoulder and bolt face by .016”. When sizing 280 Remington to 30/06 I raise the die off the shell holder .014”, I do not use 5 time fired Remington cases, I am not the fan of getting into mortal combat with a case that has more resistance to sizing than the press I am using has to overcome case resistance to sizing.

Again, there is something to sizing between neck sizing and full length sizing. When sizing cases for my M1917 Eddystone with an additional chamber length of .016” I shim the die off the shell holder .014”, after sizing there can only be .002” difference in length between the chamber from the shoulder back to the bolt face and the shoulder of the case back to the head of the case, that does not leave much room for case travel. Life of the case? There is nothing about firing a case a record number of times that entertains me, because of the generous necks in most chambers annealing is necessary.

I would suggest purchasing a feeler gage for about $11.00, some get expensive, depends on the purchases, some purchase expensive tools and spend the rest of their life talking about the expensive tool, I purchase tools and I use tools, Harbor Freight has feeler gages for about $6.00, Redding sells thickness gages, many years ago I said “Feeler gage” 3 times real fast and then immediately got over it.

Then there is the :No matter how well the case fits the chamber when the trigger is pulled the firing pin smack adds to head space by shortening the case.

My opinion and suggestion for a remedy: You know there is a problem, the chamber is longer than your cases when measured from the usual places, rather than size with a plan learn to avoid sizing, I avoid sizing by backing the die off the shell holder, rather than take a wild guestimate of a fractional guess of a turn converted to thousandths, use a feeler gage, with your chamber I would start with a .006” thick leaf. The .006” leaf will allow the die/press to avoid sizing the case to full length sizing.

Then there is Redding and competition shell holders, the competition shell holder adds to the deck height of the shell holder, another method/technique to avoid sizing. I choose to determine the length of the chamber first. Meqaning head space gages are nice but not necessary, for the 30/06 chamber there are 3 choices, go, no and beyond, I have 15 choices between .000 and .014”,

F. Guffey