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Old February 13, 2013, 11:10 AM   #12
F. Guffey
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Join Date: July 18, 2008
Posts: 2,641
Knurls? On a case, above the case head? And then the part about being new, can you feel the knurl? Is the knurl raised above the case?

Not long ago there were a few micro managers describing what happen to the case when chambered, the extractor pushed the case head to one side then the case was canted and the case was not centered etc., etc.. About the same time one of them could not find the three rings of steel advertised by Remington. I was not much help, I kept insist he look in his hand, “the bolt, it’s in your hand, the third ring is on the face of the bolt?” Point? If the case did not center in the rear of the chamber someone outside of reloading could knurl the case above the case head to take-up slack, if they really thought it was necessary to overcome all the evils presented by the micro managers.

Match, after the match the case with the match or NM head stamp is an additional variation of a head stamp that allows me to sort cases, the year stamp is an additional aid. Back to the knurl, after firing and sizing the knurl will no longer be raised (if it was a knurl to raise the metal), back to sorting after tumbling, with different head stamps I manage to return fired cases back in the same 20 case holder they started in. again, sorting, the knurl helps to identify the case when sorting, not necessary to look and sort by looking at the head stamp.

Head space of the case, head space in the chamber??? Pick one. SAAMI does, SAAMI identifies the chamber as having head space, easy to find, little circle ‘O’ with a + captured inside of it, head space minimum/maximum. The case diagram/illustration/drawing does not identify head space as it relates to the case. Case length? Yes, the case has a length.

Head space? The length of the chamber when measured from “the datum” to the face of the bolt. Length of the case when measured from the “the datum” to the head of the case.

Bart B. is this the same case we were discussing when I asked you the weight of the case after firing 47 times? I ask you if you weighed the case before you started"? I asked you if you saved one case for comparison as in the effect 47 firings had on the case.

Then, back to the knurl. There are are two cases stamped Match or National match, or NM , One is a 30/06, the other is the 308 W. 308W ammo has been chambered in a 30/06 chamber at matches and fired, shooters claimed their rifle handled like a doll buggy and they were unaware of the mess-up, until they noticed the cute little cases that were absent of a neck and only a hint of a shoulder/case body juncture, those that still believe the 308W is a small version of the 30/06 were amazed the case did not separate because of the difference in length between the chamber and case. The 308W case was crammed into and sized down when the bolt closed. Meaning? the case could not take off and run to the front of the chamber to brace itself when the firing pin struck, the fact the case did not run to the front of the chamber by what ever means prevented the case from locking onto the chamber in the front and then forcing the rear of the case to move back to the bolt face causing case head separation. Point?? Were the knurls placed on the case to identify it as 308W ammo.

Military brass was never annealed to be good for reloading. It's typically too hard. But it has to be that way to withstand rough handling and loading in semi and full auto firearms. When I first saw the M852 stuff when it came out in the early 1980's, I called Lake City Army Ammo Plant and asked them about it. The engineer I talked with said it was less safe for reloading than the M118 versions due to that knurled cannelure at the pressure ring. Not a good idea to weaken the case where incipient case head separations starts in the first place.

In the process of manufacturing brass there are no shortcuts, in the process annealing a case requires as many as 6 annealing's, FA in about 1957-58 took a short cut with their match ammo (they say), the cases were sold as scrap, I have 57 and 58 Match FA cases, before I was aware their was a problem I was on the 3 firing. Now the cases are in the back of the FA drawer.

Wildcatting and forming: Someone somewhere answers the phone, it is human nature to feel compelled to give an answer, I am under no obligation to take them seriously, I question some of the answers. Given the opportunity, I purchases pull down ammo, cases? A case former can not have enough new cases, nothing like starting with a new case. Expanding the neck from 30 cal to 35 Whelen or 338, is the first step when forming and wildcatting. If what the technical adviser claimed at LC was true I would have found a problem with his theory/rational about annealing. Second step, sizing the case neck back down to 30 cal or smaller.

Point? I have green and orange boxes of new unprimed Remington cases, they are old, still I reach for the LC cases when forming and necking up, I paid from .07cents to .11 cents each for the LC pull down, for the rest of my reloading and forming a case will never cost me more than .11 cents each.

“Not a good idea to weaken the case where incipient case head separations starts in the first place” again, a reloader should learn to limit case travel. Determining the length of the chamber and off setting the length of the chamber is very manageable, the reloader must learn to control the length of the case when sizing. Once the case shoulder is formed to the shoulder of the chamber apply the leaver policy, once it is there leaver there.

F. Guffey
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