Hot looking rifle! Proud poppa stuff.
In regards to the .308 vs 7.62x51 question, I have searched far and wide about the headspace and pressure issue. I have a chinese M1A and an FAL, and wanted to be sure what was going on.
This is about the pressures:
"It's an Internet Rumor that just won't die.
You cannot compare the military measurement, which is 52,000 PSI with the copper crusher gauge to the SAAMI 62,000 PSI which is a piezoelectric transducer gauge measurement.
Military measurements in CUPs VS SAAMI in (piezo) using other calibers such as the 30-06 show about the same spread.
In reality, Max pressure for .308 and 7.62x51 are about the same.
DIE RUMOR DIE! "
And this from another guy:
"According to the SAAMI chart I have:
.308 Winchester: 62,000 psi
7.62 x 51 NATO : 60,200 psi"
This is about the headspace difference:
Chamber Head space Gauges
308 Winchester (SAAMI) Gauges
GO ....- 1.6300"
NOGO - 1.6340"
FIELD - 1.6380"
Shop (Military) 7.62x51 NATO Gauges
GO ....- 1.6350"
NOGO - 1.6405"
FIELD - 1.6455"
Several gentlemen had written to several gun manufacturers and posted the responses. Most of the company replies were that it was perfectly ok to shoot .308 OR 7.62x51 in their rifles. A bolt action gun was replied to that the action was built for .308 and 7.62 should not be used.
What I took away from all the web pages:
The 7.62x51 chamber is a little more generous in the military rifle than a civvy .308. This would allow for manufacturing variances by plant and country of origin. Also, battlefield dirt. .308 brass is not as robust as the military 7.62. Put the weaker brass into a military chamber and if there are any headspace issues there could be a FTE with the base ripped off and the rest of the brass stuck in the chamber, or a case rupture. Thus, in the end, it’s an individual rifle and owner issue, and suspect headspace issues should be dealt with by a qualified gunsmith.
