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Discussion Starter · #1 ·
A guy at the range told me replacing a bolt can change the headspace sometimes in an M1.

Does anyone know if one can determine before you place a different M1 bolt in what direction (less/more) the headspace will change?

Can I specifically buy a bolt that is "short" to get insufficient headspace closer to ANSI minimum? And if YES where?
 

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Headspace will change from bolt to bolt, and some may be the same, but most of the time it will be different with different bolts.

The best way to check the headspace is with "HeadSpace Gages" which can be purchased from various companies (Brownells comes to mind, but there are many others). You should get the "NoGo", "Go", and "Field" Gages, which are usually available in a set.

When you check the headspace do it with the bolt disassembled, and in the receiver. Clean the chamber scrupulously clean, and never force the bolt closed. Light finger pressure should be all you need to use (forcing the bolt closed could essentially destroy your headspace gage).

The theory is that a bolt should not close on a "NoGo" or a "Field" Gage. If it closes on a "Field" gage it is considered "UNSAFE TO FIRE".

In "Hatchers' Notebook", Hatcher goes to some lengths to find out what happens when there is excessive headspace. He found that if the headspace is more than what the "Field" gage allows, the big danger is that a case might rupture, allowing the gasses to blow back into the shooters' face. Most modern rifles including the M1 Garand, the M1917 (P-17, oooh that grates), the 1903 and 1903A3, and later are designed so that the escaping gasses are diverted and will not go back into the shooters face. There can be exceptional conditions, however.

I have fired several rifles that had excessive headspace, unknowingly. You can't always check the headspace before firing another persons rifle, and maybe I shouldn't have fired them, but I did. The rifles, M1 Garands, Chinese M14's, M1A's, and a few others. The rifles functioned normally.

The big danger with a semi-auto rifle is that when a case separation occurs, part of the case might be left in the chamber, and the rifle will try to stuff another round into it. If the new round goes far enough into the old case in the chamber, it is possible for several things to happen, none of which you ever would wish on your worst enemy, including instant reduction of the rifle to scrap metal.


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@ Gyrene: Good to know and keep in mind :)

@ Killer: Is that a "plastic" stock on that picture?? Why???

M1D-Garand
 

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Discussion Starter · #4 ·
I have a beautiful wood stock with 6 coats of finish, but at the time of that picture I had a nerve injury in my right hand and I needed a thinner grip area which the Ram-Line stock has.

The M1 was mad for awhile that I had dressed it up in plastic, but I can now open my hand fully without pain, and the M1 is dressed in wood again.
 
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