Join Date: July 18, 2008
In Roy Dunlap’s book on gunsmithing are illustrations and specifications for chambers and cartridges, in the 30/06 section he list two chambers, one for the 30/06, the other for the M1 Garand. The M1 Garand was said to be different because of the additional clearance in the rear of the chamber, .0002+ to aid in extraction. The M1917 Remington and Winchester were very fine rifles, the Eddystone, quoting Roy Dunlap, was anyone's guess.
Again, I have one with .016 thousandths head space as in the chamber is longer by .016 thousandths from the bolt face to the shoulder of the chamber than the case is from the head of the case to its shoulder.
It is not easy to find cases long enough for that chamber so I use 280 Remington cases, I adjust the 30/06 forming die off the shell holder .014 thousands, raise the ram, form the case then finish by sizing with a full length sizer die and a .014 thousandths gap between the bottom of the die and and top of the shell holder. again, I use new and or once fired cases.
As to picking up and or purchasing brass at the range with perceived problems, I (have) purchase range brass, 280, 270, and 30/06 for .08 cents each with an additional 10 thrown in for each 100, JIC. My favorite cases are cases fired in trashy old chambers, again, I want cases that are long from the head of the case to its shoulder, I do not want cases that exceed maximum case length, for the 30/06, that would be 2.494. Trashy old chambers? Most of the brass purchased at the range have the the appearance of being bent, misaligned or deformed, seems when the bolt closes and the handle is rotated it gets dark in the chamber and the light goes out in the shooters head, on a control feed the case head is supported between the extractor and left side of the bolt, once the case chambers and the bolt rotates the support for the case head on the left side moves to the top, leaving the case head unsupported on the left side, that means nothing to those with ‘lights out’ for me and trashy old chambers? I separate cases, fired in push feed, fired in control feed, (Speaking of of push feed, I can not remember who it was that was hollering, seems they could not find the ‘three rings of steal’ promised by Remington, I had to holler back, look in your hand, it is in your hand, you removed the bolt, it is in your hand)
Epiphany: Gunplumer, I believe you had an epiphany, you chambered a round, pulled the trigger, fired then extracted a fired case, at that point in your story I am wondering when you, the gunplumer is going to start measuring, and then finally you full length size the case and then measure the length of the case and discover the case is .020”-.025” too long? The fact your cases increased in length has little to no value if you do not understand measuring before and again after. Full length sizing and moving the shoulder back is an illusion.
Military chambers are different? We ( I ) have thousands of military cases fired in military chambers with crimped primers, I have military 30/06 cases that are unfired, I have no fewer than 8 military type 30/06 rifles, I have take off barrels, and what does all this mean, I am going with Roy Dunlap, all 30/06 chambers were designed to fire the same ammunition, the M1 Garand, in the beginning had a generous? chamber.
The M1917, a gunsmith in Utah was credited with stretching receivers because of his methods and techniques, he was accused of using a field reject gage (only). My Eddystone with .016” head space never got to Utah, my M1917 that did get to Utah does not have a long chamber. As to the Utah’s smith and his methods, I can check the M1917’s head space, in thousandths, with a field reject gage, or a 280 Remington case without stretching the receiver, and I believe the Utah smith was smarter than his accusers.
I know Bart B. has all this figured out, the 308 Winchester, when fired in a 30/06 chamber head spaces on the case body/shoulder juncture, meaning the shoulder of the 308 W is not supported and when fired forms to the chamber. Then there are those that claim they fired 308 W ammo in a M1 Garand and claim the M1 handled like a doll buggy, and I upset them by asking about the gas system drop in pressure and case extraction/ejection, I ask, “Shouldn’t the shooter suspect something was wrong when cases had to be manually ejected” to me that is something the shooter would remember, time is a factor, when the 308W case formed to the chamber time elapsed, the time it took for the case to fill the chamber caused a drop in pressure etc., etc.. the 308 W is larger in diameter by .011” than the 30/06 chamber at the contact juncture between the 308W case body/shoulder juncture and chamber. Firing 308 W in a 30/06 chamber is a bad habit.
Last edited by F. Guffey; March 26, 2012 at 07:53 AM.