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03/a3 #2

MIKE WISKEYMIKE WISKEY Member, Moderator Posts: 9,987 ******
edited November 2014 in Ask the Experts
"When you say short chambered what do you mean?
Which gage will go and which wont go?"............it means the chamber is too short, the bolt will not close on a 'go' gage (or standard ammo). the chamber has to be finished reamed slightly deeper.

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    nmyersnmyers Member Posts: 16,881 ✭✭✭✭
    edited November -1
    So, wouldn't it be easier to answer the original question if the OP told us if the barrel is used, or New Old Stock?

    Neal
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    AmbroseAmbrose Member Posts: 3,173 ✭✭✭✭
    edited November -1
    Per Hatcher's Notebook, headspace specs for newly manufactured rifles are 1.940 minimum and 1.944 max. 1.946 is the maximum for rifles returned for overhaul. Field checking maximum is 1.950. Hatcher was writing about 1903 rifles, not A3's. FWIW: My Forster No Go gauge is marked 1.946.

    Hatcher also mentioned that Garands were held to 1.942-1.944.
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    v35v35 Member Posts: 12,710 ✭✭✭
    edited November -1
    I used 1.940, 1.946, 1.950 & 1.951 Ordnance headspace gages on Garands, BARs, A4 Springfields and some '06 Arsenal Jap 99 conversions in FECOM 7th Div Ordnance.
    Which gage do you call a Go gage in 30-06?
    Headspacing testing with live ammunition was never done.
    Dimensions fell within a .011" headspace range.
    My question was; how short were Spfld replacement barrels chambered in your experience?
    Were they less than the 1.940 gage?
    While I never replaced an A4 Spfld barrel, I have replaced Carbine, Thompson and BAR barrels and all had timed threads.
    Headspace always gaged within Army limits.
    Carbines were also gaged.
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    AmbroseAmbrose Member Posts: 3,173 ✭✭✭✭
    edited November -1
    From what I've read, the bolt should close on a 1.940 gauge which would mean that the chamber is at least that long. And not completely close on a 1.946 (or 1.944 in the case of new 1903's) which means the chamber is shorter than that. If the bolt will not completely close on a 1.940 gauge, the chamber is too short. Your question, from a previous post, as I understand it is ".004 short of what!". I would think it would be between 1.936 and 1.939, the 1.940 being the "Go" gauge. Deepening the 1.936/1.939 chambers by .004 would create headspace within the specs for new Springfields.

    Having typed all that, it appears that your experience with headspace gauging is greater than most of us here. My own experience consists of 55+ years of handloading and rifle collecting as well as a good bit of affection for the 1903 and A3 rifles.
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    v35v35 Member Posts: 12,710 ✭✭✭
    edited November -1
    I don't know what the respondent used as a minimum go gage. That should have been stated.
    While minimum headspace would be desirable on hunting/target rifles, it probably wouldn't work under combat conditions in mud, snow, dust and ice.
    As I recall from 60 years ago, the 1.951 was a field no-go gage and the 1.950 a field maximum go-gage for all 30-06 arms.
    Arsenal, Depot and factory very likely have their own criteria for new, rebuild, reissue, salvage etc.
    Considering allowable headspace at that time, my own experiments
    with copper crusher pressure tests in '82,ranged between 40-75 KPSI CUP, suggesting a narrower allowable headspace range of less than .006" to avoid cast separation.
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