7.62Nato vs 308Win

O

oberkommando

New member
I have M1A with 1.6320" chamber head space which is below NATO and into 308 area, problem is, I have considerable Lake City brass for reloads, can brass be sized down enough for this chamber, or should it be reamed larger to mil spec. ( chamber for 7.62 NATO is 1.6355" min and 1.6405" max) Average size of NATO Cartridge is 1.6320" which would leave zero or a minus head space condition with many NATO rounds, (at least factory loaded) do not want gun firing out of battery.

My problem is that the 7.62 cartridges in the average are 1.632"+ CARTRIDGE HEADSPACE exceeding 308 Win. min. CHAMBER HEADSPACE 1.630"MIN., 1.634" no-go,and 1.638 field reject.

Custom dies from chamber casting?
 
Mine is also headspaced at 1.632, and I have put hundreds of 7.62 NATO through it and about a hundred rounds of .308. (The 7.62 is cheaper to buy)
At 100 yards my 7.62 groups average around 5/8ths of an inch, and the .308 groups around 1/2".
The only problems I've ever had were surplus mag problems, which were easily fixed.
Good luck and Happy shootin'!


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Happiness is a tight group!
 
Thanks Outlaw1 I thought it should work but have only used federal brass up to now. Also, a buddy of mine has HK91 with NATO CHAMBER and we have fired both with no problems.

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The beauty of the second Amendment is that it is not needed until they try to take it. T JEFFERSON
 
No problem, just thought I would share that bit of info.
I too, was a little concerned at first, but I have a shooting buddy that builds and customizes M1A's for a living. I asked him about the headspace. His answer was rather long and complicated, but in short he said "Shouldn't be a problem".
I also found the same thing in my FN-Fal, just the groups were a little bigger. ;)

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Happiness is a tight group!
 
Do a search on Deja.com in rec.guns for 7.62 NATO. About a year ago a long thread had some very good technical info buried among the misinformed blatherings.

E-mail me if you can't find it. I have a saved e-mail somewhere with the exact title header, and of course the month when it was discussed.
 
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