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  1. Default

    I have a M1917 rifle with a chamber that is .002” longer than a filed reject length gage. When sizing cases for that chamber I use 280 Remington cases. The 280 Remington case is longer than the 30/06 case from the shoulder of the case to the case head by .051”. I do not find it necessary to fire form, I form first then fire.

    When sizing a case for the long chamber I adjust the die .014” off the shell holder then size the case, I could use a 30/06 forming/trim die first then size but I do not find it necessary. I do believe head space gages are nice but as long as they keep installing threads in my presses and on my dies I will continue to off set the length of the chamber with the length of the case.

    F. Guffey

  2. Default

    I measure chamber length in thousandths. I do not measure the length of the chamber in go-gage length, I do not measure the length of the chamber in no-go-gage length, I do not measure the length of the chamber in field gage length, and I measure the length of the chamber in thousandths.

    And then there is the short chamber. I was thinking by now someone could measure bolt travel/advance in thousandths as in from open to close.

    F. Guffey

  3. Default

    There is a cute little saying that goes around gun smithing forums that suggest purchasing a bucket of bolts is better

    than buying one bolt. Seems the thinking suggest if the first bolt does not reduce the length of the chamber from the shoulder to the bolt face all that is necessary to do is reach for another bolt from the bucket.

    A few years ago I purchased a mill from a collector, builder of correct military rifles/reloader. He was having trouble reducing the length of the chamber of a period correct 03 Rock Island. He said he was trying to get help from one the reloading forums. I ask which one; he told me, I suggest he forget about getting help from that forum because I thought it was too social dysfunctional.

    I did tell him it was his luck day because I determine head space/the length of the chamber three different ways without a head space gage. In a few minutes I determine the length of his chamber was .0075” longer than a minimum length/full length sized case or .0025” longer than a go-gage length chamber.

    It was about that lime he handed me a 30/06 go-gage from a box of 20 head space gages. Nice, we all know the bolt will close on a go-gage. He then handed me a no go-gage for the 30/06 chamber. I told him we both knew the bolt would not close on a no go-gage unless the chamber is longer than a no go-gage. I told him the chamber was .0025” shorter than a no go-gage length gage.

    Then came time to reduce the length of the chamber; I offered to form cases that would fit. He wanted to use a bolt; problem, he had no fewer than 100 03 bolts and none of them would reduce the length of the chamber .0025” but I offered to check every bolt he had warning him this period correct rifle required a straight handle bolt.

    I informed him I have 35 06 replacement bolts for the 03A3 and none of them have a straight handle and I knew none of my bolts would reduce the length of his chamber by .0025” but I did not mind trying.

    He was going to use new factory R-P ammo for testing the rifle.

    F. Guffey
    Last edited by fguffey; 08-17-2016 at 05:36.

  4. #14

    Default

    I take the military brass situation in general with a lot of grains of powder

    In 30-06, I see it weight less than FC and RP.

    Less weight, more space. A member of another forum had a rule of thumb that it took 17 gr case weight to equal a grain of powder.

    Other brass of course may vary and I may not have seen all the 30-06 variations, digital scale is a great asset for quick checks though.

    If I had a extra large chamber I would consider FC brass as its softer, probably contour to the chamber better and then deal with re-size to suit.

  5. Default

    In 30-06, I see it weight less than FC and RP.
    I am trying to determine what 'it' is. It weighs less than FC and RP? IF FC and RP are 30/06 cases; what is 'it'? Straight across the board Winchester military 30/06 cases weighed less than any other 30/06 military case; Winchester 30/06 cases were stamped WW, WCC, WRA and Winchester.

    F. Guffey

  6. #16

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    FC are the heaviest. From memory of 205 gr.

    RP the next, something around 195 gr.

    I like RP a lot, it seems to be in between soft and hard, lasts well etc. Opinion and feeling, I can't prove it.

    Military is down in the 185 or 190 gr.

    FP is very soft, I think (opinion) it would fire form better, its also throw away as I have yet to be able to keep it more than about 8 rounds even with carful shoulder setup (based on the fired shoulder not any default dies setup.

    Along with my brother, we have measured something like 12 Model of 1917s. All were about the far end of field reject, all shoot just fine.

    As they are military we accept them for what they are and have fun shooting them.

  7. Default

    Along with my brother, we have measured something like 12 Model of 1917s. All were about the far end of field reject, all shoot just fine.
    And no one has a clue as to why? A bunch of smiths got to gather and found someone to blame it on. This stuff does not lock me up and I find no reason to make up stories, for me it is not challenging, if I have a rifle with a long chamber I form cases to fit. For most that is a complicated process because they only have cases available to them that manufacturers make available. I purchases cases that have been fired in long/trashy old chambers, when culling the cases at the range I cull the cases, I only purchases cases that are long from the shoulder to the case head. I use the length of the case from the shoulder to the case head to off set the length of the chamber.

    I noticed you did not list the length of the chamber in thousandths, you only mentioned field reject gage. I have a M1917 that has a chamber that is .016" longer than a minimum length/full length sized/over the counter/new round; what does that mean? It means a new factory over the counter round has .016" clearance between the shoulder of the case and shoulder of the chamber. If I fired cases that were go-gage length from the shoulder to the case head I would have .011" clearance. But, because this stuff does not lock me up I use 280 Remington cases, when sizing the 280 Remington cases I adjust the die off of the shell holder .014" with a feeler gage and then size the case. After sizing and trimming I load and then chamber the case, after chambering I have the magic .002" clearance between the shoulder of the case and shoulder of the chamber. I have asked many times where did the magic .002" come from? Almost all reloaders respond with "I bump...."

    .016"? Reloaders believe the case has head space, they believe .016" is too much head space and the case will have case head separation. And then I say the shoulder on my 30/06 cases do not move when fired in my M1917 and none of them understand what I am talking about.

    F. Guffey

  8. #18

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    The head space thing has gotten to be quite the myth. I have done a standard write-up that I think it clear.

    If the headspace is too long the gun won't fire. Shell moves forward with the firing pin hit and simply won't shoot.
    If its marginal (per SAMMI) then it will fire fine, blow the case out and if you do a minimum shoulder bump back you have a fire formed case that is fine.

    303 had generous head space and chambers. You cant reload it more than 3 times, it does not kill anyone.

    If its too short no new brass will fit. Self fulfilling you can't shoot it

    In between its also not an issue.

    You get better accuracy with fire formed to the chamber and minimum bump back but I suspect that's under 1/2 MOA
    All my 1917s push the very limit of field reject. They just get their own brass.

  9. Default

    [QUOTE=RC20;508345]The head space thing has gotten to be quite the myth. I have done a standard write-up that I think it clear.

    If the headspace is too long the gun won't fire. Shell moves forward with the firing pin hit and simply won't shoot.

    I have done a standard write-up that I think it clear
    You think it clear? I have always said there are a lot of events that happen between pulling the trigger and the bullet leaving the barrel reloaders simply do not understand. "If it is too long?" Meaning the chamber from the shoulder to the bolt face? And you done a standard write=up?

    I chambered a round in a rifle, I pulled the trigger and the bullet left the barrel. I ejected the case, the case was ejected with just a hint of a neck, the shoulder on my case did not move. I could ask "What does that mean"? Because of the failure of the reloader to understand the events between pulling the trigger and the bullet leaving the barrel asking the question "what does that mean" is a wasted effort.

    The case that was ejected with the hint of a neck: I moved the shoulder on a chamber forward .127" forward meaning I increases the distance from the shoulder to the bolt face .127": After increasing the length of the chamber I chambered a case that was shorter from the shoulder to the case head (minimum length/full length sized case in the long chamber, closed the bolt and then pulled the trigger.

    The case, bullet, powder and primer did not out run the firing pin, the case did not move and because of this miracle the case head did not move from the bolt face. My firing pin busted the primer before anything took off for the front of the chamber. I know that is what happened, the case proves the case did not take off for the front of the chamber. I do not make this stuff up; reloaders believe they can move the shoulder back, they believe they can bump the shoulder back. I can't, it all goes back to reloaders not understanding what happens between pulling the trigger and the bullet leaving the barrel.

    F. Guffey

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