If you are NOT shooting reloaded ammo in your 14,
the simple answer about headspace in the Chinese M14 clones,
is stop worrying, and get out and shoot.
BUT,
if you want to reload for the M14,
KNOW WHAT YOUR HEADSPACE IS,
understand the differences between a 7.62 NATO and a .308 Win CARTRIDGE CASE,
AND UNDERSTANDTHE RELATIONSHIP BETWEEN HEADSPACE AND CASE STRETCH!
At my last clinic we checked headspace on eight M14 rifles, all Chinese, varying from brand new out of the box 2007 Norcs, and a brand new 2009 Bell/Poly, to well shot, customised, etc.
After careful inspection of the bolt lugs, to confirm that both lugs were touching the receiver, and that the bolts were wearing evenly ... aka ... straight with the bore, then and only then, are you ready to start checking headspace
Headspace was checked using two 7.62 NATO gages, cut out for the M14 ejector, so we did not have to strip the bolts.
7.62 GO gage was marked as 1.6315",
which would be my MINIMUM recommendation for a carefully cleaned rifle, shooting clean 7.62 ammo, or commercial .308 WIN ammo. I would use this tight dimensioned chamber quite cheerfully because, unlike what the military expects and plans for, I do clean my rifles every year or so ...
whether they need it or not.
7.62 NO GO gage was marked at 1.640",
which is exactly .010" larger than .308 Win GO, and about .004" longer than SAAMI .308 NO GO. This 1.640" dimension is approximately .004" UNDER what the military considers the absolute bitter end for a 7.62 NATO chambered rifle.
This NO GO is good enough for govt work ...
especially for us civilians who will NEVER abuse our rifles like the military expects and plans for.
Of the eight rifles checked, all were between 7.62 GO, and 7.62 NO GO,
with only two closing TIGHT on the NO GO gage, with absolutely no room for any play.
Draw your own personal conclusions from this ...
but personally,
Even though this is a bit more than the SAAMI "Lawyer Proof" standards for .308 WIN, I would shoot NEW comercially loaded .308 AMMO, or 7.62 NATO BALL ammo, out of any of the 14s we saw at the clinic, without any worries about a NEW case, .308 or 7.62, ever seperating. In fact, I have personally shot NEW commercially loaded .308 Win 168 Gr HPBT match out of a brand new out of the box Chinese M14 rifle with a measured headspace of 1.645", and not only do I still have both of my eyeballs, but the rifle shot a few sub-MOA groups.
Not that I recommend this practice to anyone else,
but
BTDT personally on a few occassions,
and still no seperated cases.
STOP WORRYING ABOUT EXCESS HEADSPACE IN THE M14.
If you really want something to worry about,
think about bolt/receiver/firing pin timing,
and SLAMFIRES.
Remember please,
headspace is just one small part of the safety inspection for your M14 rifles.
And remember,
while long headspace with NEW cartridges in the M14 hasn't hurt anyone yet that we can document,
SLAMFIRES,
caused by too tight a chamber,
too long reloads,
dirty chamber,
stuck firing pin,
broken firing pin,
poor receiver bridge,
too much firing pin extrusion,
improper firing pin tip [ at the front or especially at the rear ]
etc, Etc, ETC,
potentially CAN cause a catastrophic M14 Kaboom.
Of all the M14 rifles we checked for receiver bridge/bolt lug/firing pin timing, two were a bit scary, and might allow a firing pin into the primer a bit sooner than we would prefer. All the Chinese firing pins we checked were ground at the proper angle, but were ground deeper than the NEW GI firing pin we looked at. In fact, all of the 14s at the seminar could have tightened up the firing pin/bolt lug safety margin a bit by swapping in a NEW GI firing pin.
AS if anyone really cares??
PS: Throwing in a NEW GI firing pin MAY help a bit with increasing the safety margin of the timing of your Chinese M14 rifle, but once agin,
this is NOT a simple thing to do,
unless you understand the relationship between firing pin maximum protrusion, firing pin length, and the rear tip of the firing pin, you might want to get a genuine M14 Gunsmiter to do this for you.
Or come to the seminars and learn about it ...
There!
Now we can all stop worrying about headspace in the M14 ...
and go on to worrying about bolt lug depth/receiver bridge wear or out of spec/worn or too long firing pins,
etc.
I hope this helps everyoine sleep better at nights,
if so,
then my work here is done!
[;{)
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