The Firing Line Forums - View Single Post - Thinking of buying a 7.62 Spainish Mauser

Ignition Override · July 3, 2011, 02:40 AM

chack:

Some quite seasoned Mauser guys told me that converting from cup pressure to Saami psi involves a correction factor of about 10,000 psi.
Another problem is that many people fail to differentiate between the FR7 and FR8.

This is reportedly why NATO 7.62 is around 58,000 and commercial .308 is 62,000. Considering that test (proof) pressures were another 50% or so Higher, combined with the 8mm action, the FR8 should be safe with .308.
My FR8 has had very limited wear.

Even an article at "Surplusrifle": "The Spanish Mauser Inquisition" (by Trope and Jeo) mentions the FR8 at the top, but then only addresses the FR7 issues with any statistics. This contributed to the confusion.

My once-used .new .308 brass looks brand new. Even though the gun did not pass the gun smith's Go gauge, which is very common for the best NATO rifles, it passed my new Field gauge (from Numerich) quite well: the bolt barely turns at all.
With 41 gr. of IMR 4064 powder and 170 grain CMP Match bullets, these .308s have been reloaded three times -full length resizing- and the brass still looks/feels fine, even the internal paper clip test.

July 3, 2011, 02:40 AM	#52
Ignition Override Senior Member Join Date: February 18, 2008 Location: About 20 nm from the Big Muddy Posts: 2,887	chack: Some quite seasoned Mauser guys told me that converting from cup pressure to Saami psi involves a correction factor of about 10,000 psi. Another problem is that many people fail to differentiate between the FR7 and FR8. This is reportedly why NATO 7.62 is around 58,000 and commercial .308 is 62,000. Considering that test (proof) pressures were another 50% or so Higher, combined with the 8mm action, the FR8 should be safe with .308. My FR8 has had very limited wear. Even an article at "Surplusrifle": "The Spanish Mauser Inquisition" (by Trope and Jeo) mentions the FR8 at the top, but then only addresses the FR7 issues with any statistics. This contributed to the confusion. My once-used .new .308 brass looks brand new. Even though the gun did not pass the gun smith's Go gauge, which is very common for the best NATO rifles, it passed my new Field gauge (from Numerich) quite well: the bolt barely turns at all. With 41 gr. of IMR 4064 powder and 170 grain CMP Match bullets, these .308s have been reloaded three times -full length resizing- and the brass still looks/feels fine, even the internal paper clip test.