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Thread: Lake City 7.62 brass sizing

  1. #1
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    Lake City 7.62 brass sizing


    I just bought a new Savage Hog Hunter in .308 and I'm using a standard RCBS full length die to size once fired Lake City 7.62x51 brass. From the effort during sizing I'm assuming this was machine gun brass and I'm worried about brass spring back.

    Question have any of you had to size once fired Lake City 7.62 with a small base die, or did you get by with a standard full length die without any hangups.

    A sized case chambers without any problems or rub marks colored with a black felt tip marker, but I'm not sure the cases are small enough in diameter with adequate spring back after firing.

    The largest base diameter after sizing is .468 but new white box Winchester .308/7.62 cases are approximately .464 and surplus 7.62 is .462 and max diameter is .470.

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    If they chamber today, they aren't going to stop chambering next week or next year if that's what you're worried about. The fact that you can get the bolt closed without a fight means you don't need a SB die.

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    Chambering isn't the problem, I'm asking about if anyone has had experience with hard bolt lift or hard extraction when using a standard full length die and machine gun 7.62 brass. Meaning was the diameter of the case reduced enough during sizing to spring back and extract reliably with a normal die.

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    I can't believe I'm the only cheap bastard that uses Lake City 7.62 brass, don't any of you "thrifty" members have any experience with LC 7.62 brass and a Savage rifle?

    There must be someone here who is so tight when he breaks wind it sounds like a silent dog whistle and uses Lake City 7.62 brass. (any thrifty Scots here?)

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    Lc brass is thick. It's always hard going through the resizing die. Made for AR's. I use it all the time in my AR 10 308. Extra lube helps. Are you a reloader? Hard bolt extraction is a sign of high pressure.
    Savage 10 FCP-SR 308, 300BO PCS

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    Basic Member Phranque's Avatar
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    Quote Originally Posted by bearcatrp View Post
    Lc brass is thick. It's always hard going through the resizing die. Made for AR's. I use it all the time in my AR 10 308. Extra lube helps. Are you a reloader? Hard bolt extraction is a sign of high pressure.
    I used 7.62 LC brass in my old model 10 before my rebuild. Yes, it is thicker, so your internal volume tends to be a little less, so pressure gets higher sooner....watch your max load, it's typically going to be a little less than book values.

    As far as resizing, it is going to be a little tougher the first go-round, but once it's fire formed to your chamber, subsequent resizings are typically easier. No, never had any issues with "spring-back". And, watch the "extra lube"... more isn't always better. Even though it is thicker, too much lube can still dimple the necks.

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    Basic Member Robinhood's Avatar
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    Ed, I matched prep after sizing with a Lee die, no expander that had the neck reamed out for years using no expander and never had a problem sticking anything even with hot heavy loads. As you know there was no neck R.O. and neck thickness was uniform. Can I ask what lube you are using on the outside of the case?


    For all of the previous and future posters on this thread, Ed has extensive experience in reloading. From what I read it is largely with old military and modern gas guns but if you pay attention to his posts he has a good grasp on the subject matter.
    The Dunning-Kruger effect is alive and well.

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    Basic Member eddiesindian's Avatar
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    Quote Originally Posted by bigedp51 View Post
    Chambering isn't the problem, I'm asking about if anyone has had experience with hard bolt lift or hard extraction when using a standard full length die and machine gun 7.62 brass. Meaning was the diameter of the case reduced enough during sizing to spring back and extract reliably with a normal die.
    You're FL die will work just fine. I've been using once fired LC Brass for years and absolutely love the brass. What I've found is that while sizing I'll let the brass sit in the die for a little extra time then pull up on the ram,then run the brass thru the die one more time. The brass is thicker and to say it has spring back is an understatement.
    Life is tuff.....its even tuffer when your stupid
    {John Wayne}

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    I'm using a home made case lube of lanolin and alcohol and tried two other brands of case lube and lubing isn't the problem. Even after sizing twice and pausing at the top of the ram stroke the cases were still .003 to .004 larger in diameter than new unfired brass. The next day I grabbed 10 of these sized cases and sized them again to see if the brass was springing back to their fired size. About half the cases required more force than normal to full length size them again.

    My main worry was if these cases would spring back from the chamber walls when fired and be hard to extract or even jam in the chamber. Last night after checking a few more sized case I ordered a small base die from Amazon Prime and it will be here tomorrow Sunday so no more problems. The small base die will be used at least once to reduce the case body to SAAMI minimum dimensions. The small base die might be over kill but I didn't want to go to the range and fire one shot and have a case stuck in the chamber.

    The Lake City brass started because the last two bags of Winchester brass I bought had six defective cases. The overall quality of Winchester cases has gone down hill or else these cases were made on a Friday close to quitting time. I bought the Lake City cases because they are made of harder brass and thicker in the base. (Made Ford Truck Tough)

    Robinhood, thanks for the comments but I just happened to shoot my milisurp rifles more than my hunting rifles. I'm 67 with chronologically gifted eyesight and have been reloading over 47 years. I sold off most of my milsurp rifle collection to buy new rifles I could put scopes on. I always preferred bolt action rifles and revolvers but my two sons told dad he needed to get "modern" so I now have a few rifles that throw perfectly good brass away and make you go look for it. "BUT" I do love the ping sound of a empty M1 Garand clip being ejected.

    When the small base die comes tomorrow I will let you know if I break the handle off my 1973 Rockchucker press.

  10. #10
    Basic Member Robinhood's Avatar
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    Ed I thought you had a SBD. I would have sent you a loaner if I had known.

    "BUT" I do love the ping sound of a empty M1 Garand clip being ejected.
    There was a generation of Japanese fighters that thought they liked it too. Until......

    Try some Chapstick and see if it helps. If so, invest in some imperial.
    The Dunning-Kruger effect is alive and well.

  11. #11
    Basic Member darkker's Avatar
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    The "spring back" you are fretting over is a function of heat treat, more than anything else.
    I've been using mountains of LC brass for Painless, and resized a pile of them into Creed as well.
    I've never had any issues just using Lee's FL dies and the same L&A case lube as you.
    Cases will only "spring back" if they are work hardened when they were stretched. Something like an Anneal-eze will allow you to continue only using standard dies.
    I'm a firm believer in the theory that if it bleeds, I can kill it.

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    Quote Originally Posted by darkker View Post
    The "spring back" you are fretting over is a function of heat treat, more than anything else.
    I've been using mountains of LC brass for Painless, and resized a pile of them into Creed as well.
    I've never had any issues just using Lee's FL dies and the same L&A case lube as you.
    Cases will only "spring back" if they are work hardened when they were stretched. Something like an Anneal-eze will allow you to continue only using standard dies.
    darkker

    When a 7.62 case is fired in a larger diameter machine gun chamber after sizing it wants to "spring back" to its fired size. The same thing happens with range pickup brass and people posting about troubles with cases fired in another chamber and not fitting their chamber after sizing. The M14 7.62 chamber is .002 larger in diameter than a .308 SAAMI chamber and a machine gun chamber is even larger in diameter and "WHY" the cases are harder to full length resize.

    After sizing this machine gun brass "twice" and pausing at the top of the ram stroke for four seconds each time, the next day some of the cases were hard to size a third time. Meaning after sitting for a day the brass sprang back and was larger in diameter. These are once fired Lake City cases and they are not work hardened by any means and the base of the case is not heat treated. Lake City cases are made of harder brass and the 7.62 cases are thicker in the base to withstand being fired in larger diameter machine gun chambers and longer headspace settings.

    Normally a full length resized case for a semi-auto should be approximately be .003 to .005 smaller in diameter than its fired diameter. This allows the case to "spring back" from the chamber walls and extract without binding in the chamber.

    My .308 small base die will be here today and all the cases will be sized once with the small base die to reduce them to minimum SAAMI body diameter. Thereafter hopefully my standard RCBS .308 die will only be needed to be used during sizing for these machine gun fired 7.62 cases.

    Bottom line, I asked my question in three different reloading forums and got mixed answers about what die to use, so I ordered small base dies and problem solved.
    The cheap bastard had to spend more money on dies to make up for buying much cheaper once fired military brass built Ford Truck Tough.

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    I have used only AR dies for my LC brass. Never had an issue. But only use LC brass in my AR10 308.
    Savage 10 FCP-SR 308, 300BO PCS

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    My small base .308 die arrived since my last posting and on average the case diameter near the base was reduced .002 more than my standard RCBS .308 die.

    The 300 once fired Lake City 7.62 cases I bought are no longer a problem.

    Thank you for your advice and help.

    NOTE, My standard Lee .308 full length die reduced the case diameter .001 more than my standard RCBS full length die. And the RCBS small base die made the cases a little over .001 smaller than the Lee die.

    And my Lee .223 full length die reduces the case diameter more than my RCBS AR Series .223/5.56 small base die does. So again nothing is written in stone when it comes to chambers and dies and they both can vary in size.

  15. #15
    Basic Member darkker's Avatar
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    Quote Originally Posted by bigedp51 View Post
    darkker

    1) When a 7.62 case is fired in a larger diameter machine gun chamber after sizing it wants to "spring back" to its fired size. The same thing happens with range pickup brass and people posting about troubles with cases fired in another chamber and not fitting their chamber after sizing. The M14 7.62 chamber is .002 larger in diameter than a .308 SAAMI chamber and a machine gun chamber is even larger in diameter and "WHY" the cases are harder to full length resize.

    2) These are once fired Lake City cases and they are not work hardened by any means and the base of the case is not heat treated. Lake City cases are made of harder brass and the 7.62 cases are thicker in the base to withstand being fired in larger diameter machine gun chambers and longer headspace settings.

    3) Normally a full length resized case for a semi-auto should be approximately be .003 to .005 smaller in diameter than its fired diameter. This allows the case to "spring back" from the chamber walls and extract without binding in the chamber.
    1) Right, but you missed my intended nuance. It will want to "spring back" to a pre-sized state, if it has been work hardened. This can result from multiple sizings/loadings, or from excessive stretching to a large chamber. Can't recall if the M60 has chamber scallops or not, but those buggers on FAL's can be problematic for that.
    2) All cases are spec'd to a set of standards. As far as anyone stating the alloy or specs for such, that I'm aware of the last to do so was Olin in the 1950's. ATK is operating LC, and last I knew that ammo was required to do a thing for a total of 1 firing. If you want "accurate" cases, then as Federal has long done with the GMM, you make your brass in a rather soft state. This allows obturation to happen quickly and seal to any chamber dimension. However you don't want a soft case head, this part of the case can be substantially different than the rest of the cases state. I know that there are mountains of discussion about what is or isn't a particular dimension surrounding military cases. So rather than get into that old chestnut, think of it more as a matter of practicality of what is Currently being done. Which is more reasonable to assume: That for the 7.62 only, that cases are made differently depending upon whether or not they will go to SAAMI or NATO chambers. OR that there is one case being made, and can be stamped and used per any given order?
    3) That number as you eluded to, differs between die makers. Not everyone who makes dies uses the same specs.

    Hope you SB dies fixes your issues and it works for you. I've never had to go that route with any of my military brass, but understand the frustration.
    I'm a firm believer in the theory that if it bleeds, I can kill it.

  16. #16
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    It seems you did not even fire one of these.

    If it fits the chamber, then it will swell and still spring back enough not to be an issue.

    If you really are worried, get a brass rod form Lowes etc and you can pop it back out.

    It seems like its a projected issue not a real one.

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    Quote Originally Posted by RC20 View Post
    It seems you did not even fire one of these.

    If it fits the chamber, then it will swell and still spring back enough not to be an issue.

    If you really are worried, get a brass rod form Lowes etc and you can pop it back out. m

    It seems like its a projected issue not a real one.
    Nothing odd about it, neck sized cases can stick in the chamber, partially full length resized cases can stick in the chamber. Just because a case chambers doesn't mean the case will spring back from the chamber walls after firing and not hangup. In a semi-auto a full length resized case should be .003 to .005 smaller in in diameter than its fired diameter to be able to extract reliably. These Lake City cases were fired in a machine gun with a chamber well over .003 larger in diameter than a SAAMI .308 chamber.

    I asked my question to see what dies people used without problems with 7.62 machine gun brass. The problem is not many cheap bastards like myself buy this brass because of the problems you can run into, and why you and others asked the same question.

    Bottom line if you had read about the problems with machine gun brass with sizing and extraction you would understand. Added to this is the fact that resizing dies vary in diameter and nothing is written in stone. And I wasn't going to drive to the range and fire one shot and have to come home with a case stuck in the chamber. Once the base diameter is reduced to SAAMI minimum dimensions these cases can be sized with a standard .308 die.

    Now a odd part about 7.62 machine gun brass I learned and tried today. If you full length resize the case in a 30-06 die first and a second time in a standard .308 die, a small base die is not needed. When I sized these 7.62 cases with a standard 30-06 die I could not believe the effort required to just size the base of the case.

    Quote Originally Posted by USSR View Post
    Big Ed,

    I've resized my share of MG fired 7.62x51. In fact, if the headstamp don't say "MATCH", "NM" or "LR", I automatically assume it's MG fired and run it thru a .308 SB die. However, one time the brass was so blown out in the web area that I could not get the case to fully enter the die despite using copious amounts of Imperial Sizing Die Wax. So, having heard of the .30-06 sizing die trick, I tried it. Instead of resizing the case body all the way down the case, with it getting progressively harder as you reach the web area, you are making zero contact with the case body, shoulder and neck, and only resizing that .25 inch or so part of the web that is giving you all the trouble. Of course, you then have to follow up by resizing with a .308 FL sizing die, but it now becomes quite doable. It's simply a last resort method. Hope that helps.

    Don
    After sizing with a 30-06 die and sizing again with a small base die it was like sizing new unfired brass to straighten the necks.

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    There is one of the common straight wall open top pistol body dies that works really good for body resizing back to .468 or less, sorry but can't remember which one (45ACP?). 308/243/6BR etc. resizes the base only. The info is out there.
    Recheck your case OAL after using a small body die, they cause significant length growth, .005"-.010" on a 223 case.
    Imperial sizing wax highly recommended for this operation.

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    Quote Originally Posted by Scott Evans View Post
    There is one of the common straight wall open top pistol body dies that works really good for body resizing back to .468 or less, sorry but can't remember which one (45ACP?). 308/243/6BR etc. resizes the base only. The info is out there.
    Recheck your case OAL after using a small body die, they cause significant length growth, .005"-.010" on a 223 case.
    Imperial sizing wax highly recommended for this operation.
    I asked my question in three different reloading forums to find out what dies worked the best with machine gun brass. At the CMP forum using a 30-06 die and the .45 acp die were mentioned and the .45 acp die did not size as far down as far as the 30-06 die. But there can be a concentricity issues using these dies because the case in not fully supported. I tried both the 30-06 and .45acp carbide die after I got the .308 small base die and after getting the small base die using the other dies were pointless.

    Now all I have to do is do some loading and see if saving money buying the Lake City brass was worth all the effort sizing and uniforming the cases. I will say the neck thickness was more uniform on the Lake City than two new bags of Winchester .308 cases.

    Prior to this I had been buying bulk once fired Lake City 5.56 brass and all of it was sized first with a small base die. Thereafter I use a standard .223 full length die for my AR15 and Savage .223.

    But again, resizing dies and chambers do vary in size and noting is written stone when it comes to sizing brass.

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    Biggest issue with 7.62/5.56 once fired is what they were fired in, and what your chamber reamer was. The auto chambers are very generous and pretty much make the brass not worth saving unless there's a severe shortage like 2010-2012. 5.56 you can tell pretty easy by the nasty extractor stamp the SAW puts on it.

    PTG likes to slip in the small base 'tight' chamber dimension on all their 223 based reamers incl. wildcats, suffering thru this exact issue right now on 20 Practical.

    Best deal right now for 7.62 brass is Wideners has 1000 IMI 308 cases for $300.00-$330.00. IMI is good stuff.

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    Scott Evans

    My question was what dies do you use when sizing 7.62 Lake City machine gun brass for a .308 SAAMI chamber.

    I buy bulk once fired processed Lake City brass from Brass Bombers.

    .308/7.62 - Cleaned, Deprimed & Swaged - LC Only - 1,000 Pieces $179.00 Free Shipping!! ( a better deal )

    http://brassbombers.com/308-762-Clea...-7LC-S0100.htm

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    Basic Member hardnosestreetcop's Avatar
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    I agree with what Phranque said "Yes, it is thicker, so your internal volume tends to be a little less, so pressure gets higher sooner....watch your max load, it's typically going to be a little less than book values.

    As far as resizing, it is going to be a little tougher the first go-round, but once it's fire formed to your chamber, subsequent resizings are typically easier. And, watch the "extra lube"... more isn't always better. Even though it is thicker, too much lube can still dimple the necks."
    I will add only this another way of not deal with the thick brass is after fire forming in your chamber, Neck size those case's and Full length Resize only when you have to.

  23. #23
    Basic Member Robinhood's Avatar
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    Ed, In short. I purchased a small base set for the lr308 thing and found it was not required. I used all sorts of Surplus LC and it usually performed the same or better as the LC match I had from the 70's and 80's. Most firings were with 43.X of 4064 or varget and 185 bergers or 175 SMK's. Multiple firings with no primer pocket issues.
    The Dunning-Kruger effect is alive and well.

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    I bought the gauge below for .308/7.62 for checking the sized machine gun brass case and as a final "plop test" of the loaded rounds.
    The gauge is cut with a match finish reamer and all my cases sized with the small base die fit perfectly.
    After the first firing and forming to my chamber I will use the standard .308 die.

    JP Enterprise Semi-Auto Case Gauge .308
    Optimized for semi-automatic rifles, the second generations JP Case Gauge guaranties function of your ammo. If it fits our gauge, it will fit even a minimum-depth SAAMI chamber without interference.nterprise



    Below the Wilson and Dillon .223/5.56 case gauges only check shoulder location. The JP Enterprise gauge also checks case diameter and as you can see the base of the case does not drop as far into the gauge. I had a few once fired Lake City 5.56 cases sized with a standard .223 die that would not fit this gauge and was loading for two AR15s and a Savage .223. This is the main reason I asked the question which die everyone was using with 7.62 machine gun brass.



    I use the Hornady cartridge case headspace gauge for checking shoulder location, but the JP Enterprise gauge was the only gauge I could find that also checked case body diameter.

    And since I was getting different diameter readings using the standard .308 die I decided to size the cases once with a small base die.

    And again thank you all for your help and advice, after over 47 years of reloading this was my first experience using machine gun brass.

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