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Thread: Stress relieving case necks and shoulders for long life.

  1. #1
    Member Hummer's Avatar

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    Stress relieving case necks and shoulders for long life.

    https://drive.google...iew?usp=sharing


    When I got to the Army Small Cal Weapons Lab I had access to some really knowledgeable people. As it turned out the Army did something right for a change. That was to place all the small arms entities into the same arsenal so I had access to weapons guys and ammo guys and we were only about 1/2 mile apart.


    Shortly after I got there this guy comes into our office and looks me up and introduces himself. His name was Marty Tyska and he was a ammo engineer that transferred to Picatinny when Frankford Arsenal was closed. He was a gold mine of info.


    He was also a highpower shooter. I never quite understood it but the vast majority of folks in the ordnance field are not shooters and care nothing for competition so when a shooter comes on board the word is passed and not only do you wind up with shooting friends but you have access to what they know.


    Thus I got an advanced course in how to make cases last a long time. I asked Marty how he annealed his cases and the first thing he said was to the effect, "You don't want to anneal, just stress relieve because annealing takes the case to a dead soft condition."

    He also added if you take care of your cases the only reason to discard one is the primer pocket gets loose because you should never have a neck split.


    Using what I learned from Marty I have my 500 cases for my No 1 Course Gun on their third barrel. As well I reloaded one LC66 M72 match case 157 times and it is still going and primer pocket is still snug.
    I have also not used as much care and run 75 to 90 reloads on M118 cases.

    Marty used a simple method which involved an alcohol lamp like jewelers use and he placed area below the shoulder and just up to the shoulder in the flame and rotated the case in his fingers. When I asked how long he said, "Your fingers will tell you." In other words don't use gloves.


    Next he said to drop the cases on a towel. He said DO NOT DROP THEM IN WATER ! ! ! ! !


    He explained if a the neck turns DARK blue when you finish you got it too hot and it will shorten neck life and neck will crack. If your neck turns red you have ruined it. He said you want to have them come out the same color of MATCH cases which is a light or bright blue. No darker.

    Well alcohol got to be quite pricey as the druggies were buying it to assist in the manufacture of pharmaceutical products that are not approved by the Food and Drug Administration. I mean I was getting a gal of alcohol for 2.75 and all of a sudden it went to about 12.00 a gallon.



    Then I stumbled across a nice website called 6MMBR and they had a section on this subject and this guy had made up a case holder to go in a variable speed electric drill and it was one of those things you run across that was so simple, it was brilliant.


    Having a lathe I made one up and after a little learning curve I was able to switch my stress relieving to a propane torch and I can now duplicate the blue tint we see on new MATCH ammo.


    As the instructions indicate a slow rpm. I have a RPM indicator and most variable speed drills will only reduce down to 200 RPM though I have found a 3/8" from Sears I am not sure is made any longer that will go down to about 100 RPM. You can get an idea of how fast to run your drill by using a Sharpie marker and writing something on the side of the case longways and when you can't read what it says you are rotating the case a tad too fast.


    The size of the propane tip is critical. You want the smallest you can get as you want to put the heat in about a 1/4" wide area BELOW THE CASE NECK.

    When you fire up the torch you will have two colors of blue flames. You back the torch off till the INNER BLUE FLAME WITH THE SHARP POINT IS about 1" long, if yours goes down to 3/4" without shutting down even better.

    There is a segment on the History Channel where there is a tour of the Winchester facility in East Alton and it shows the cases coming down a line all rotating slowing and they are passing through gas flames, go out the end and drop into a hopper. When I saw that I started counting and about six seconds was the time they were in the flames.


    Winchester then dips the cases in something with a three letter acronym which is short for a chemical with about 40 letters in its name. That keeps them shiney for a long period. Sorry can't remember the name but the cases are tumbled to remove the blue tint prior to dipping in the 3 letter chemical. have made holders for several things. Generally I use one holder for 308 and 30.06.
    Distinguished Rifleman Smallbore Prone and Highpower Rifle, Presidents 100 (Rifle), Member US Palma Teams and US Dewar Teams. US Army Test and Evaluation Command - Certified Small Arms and Ammunition Test Director - Aberdeen Proving Ground, MD, NRA Member since age 12, NRA Benefactor, Charter Member International Wound Ballilstics Assn, Life Member Gun Owners of SC, Life Member Palmetto State Marksmen's Assn, Eagle Scout, Bhd OTA, Shriner, FF1, AC4HT,

  2. #2
    Forum Administrator Schuetzenman's Avatar

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    Great post! I may use some of this.

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