my mossburg patroit .308 has a factory warning

gmc_kurt · October 19, 2016, 07:43 PM

it says i can only fire .308 ammo to keep the warranty. it claims the 7.62 is no good to shoot.i asked 20 people if it would hurt to fire the nato out of my rifle and 10 said yes, and 10 said no.they are the same rounds, and i know you cant fire a .308 out of a 7.62 rifle.any input on this?

g.willikers · October 20, 2016, 08:38 AM

You're referring to the 7.62 x 51?
There's lots of ammo with the 7.62 designation.
There are differences between the 7.62 x 51 and the .308.
How much depends on the individual rounds, especially considering the mind boggling number of sources for the 7.62.
If you're concerned with maintaining the factory warranty, then stay with the .308, per the instructions.
The gun was probably designed for the SAAMI commercial round.
Otherwise, do the research and use what's safe.

jonnyc · October 20, 2016, 07:19 PM

"they are the same rounds, and i know you cant fire a .308 out of a 7.62 rifle."???

But they are the same round and are perfectly interchangeable.....just like your mother is your aunt's sister and your father's wife. The issue is with how the chamber is cut. A .308 chamber is often cut to much tighter tolerances than a military 7.62x51 chamber, and a slightly out-sized 7.62 might not chamber in a commercial .308.

jmr40 · October 21, 2016, 02:45 PM

7.62X51 is the military designation for 308. They are the same size, but military ammo may be loaded to different specs. But in this case 308 civilian ammo is usually loaded hotter than military spec 7.62X51. I can't see any harm in shooting 7.62 in a civilian 308 rifle.

But the hotter 308 loads fired in a military 7.62 rifle may not cycle a semi auto action reliably and over time could result in accelerated wear. But in bolt guns they are completely interchangeable. It is just that civilian loaded 308 CAN be loaded to higher pressure. That doesn't mean every box you buy will be loaded to higher pressure.

jmr40 · October 21, 2016, 02:58 PM

Added info.

The military 7.62X51 round was designed to duplicate 1950's era 30-06 performance, but in a shorter cartridge to be used in the M-14. Semi-autos need a fairly narrow range of pressures in order to operate reliably. Since the 1950's both 308 and 30-06 commercial loads have become much more powerful. Those civilian loads function just fine in bolt rifles, but military rifles were designed to operate at a specific pressure level that many commercial hunting loads exceed.

mehavey · October 21, 2016, 06:09 PM

Quote:

...and i know you can't fire a .308 out of a 7.62 rifle....

Whare did THAT little jewel come from?

October 19, 2016, 07:43 PM	#1
gmc_kurt Junior Member Join Date: October 19, 2016 Posts: 3	my mossburg patroit .308 has a factory warning it says i can only fire .308 ammo to keep the warranty. it claims the 7.62 is no good to shoot.i asked 20 people if it would hurt to fire the nato out of my rifle and 10 said yes, and 10 said no.they are the same rounds, and i know you cant fire a .308 out of a 7.62 rifle.any input on this?

October 20, 2016, 08:38 AM	#2
g.willikers Senior Member Join Date: September 28, 2008 Posts: 10,442	You're referring to the 7.62 x 51? There's lots of ammo with the 7.62 designation. There are differences between the 7.62 x 51 and the .308. How much depends on the individual rounds, especially considering the mind boggling number of sources for the 7.62. If you're concerned with maintaining the factory warranty, then stay with the .308, per the instructions. The gun was probably designed for the SAAMI commercial round. Otherwise, do the research and use what's safe. __________________ Walt Kelly, alias Pogo, sez: “Don't take life so serious, son, it ain't nohow permanent.” Last edited by g.willikers; October 20, 2016 at 08:47 AM.

October 20, 2016, 07:19 PM	#3
jonnyc Senior Member Join Date: July 20, 2009 Location: PA Posts: 1,731	"they are the same rounds, and i know you cant fire a .308 out of a 7.62 rifle."??? But they are the same round and are perfectly interchangeable.....just like your mother is your aunt's sister and your father's wife. The issue is with how the chamber is cut. A .308 chamber is often cut to much tighter tolerances than a military 7.62x51 chamber, and a slightly out-sized 7.62 might not chamber in a commercial .308. __________________ 2024 PA Cartridge Collector Show; Aug. 16-17, 2024!!! Buy...Sell...Trade All Types of Ammunition & Ordnance PM or email me for 2024 show details.

October 21, 2016, 02:45 PM	#4
jmr40 Senior Member Join Date: June 15, 2008 Location: Georgia Posts: 10,809	7.62X51 is the military designation for 308. They are the same size, but military ammo may be loaded to different specs. But in this case 308 civilian ammo is usually loaded hotter than military spec 7.62X51. I can't see any harm in shooting 7.62 in a civilian 308 rifle. But the hotter 308 loads fired in a military 7.62 rifle may not cycle a semi auto action reliably and over time could result in accelerated wear. But in bolt guns they are completely interchangeable. It is just that civilian loaded 308 CAN be loaded to higher pressure. That doesn't mean every box you buy will be loaded to higher pressure.

October 21, 2016, 02:58 PM	#5
jmr40 Senior Member Join Date: June 15, 2008 Location: Georgia Posts: 10,809	Added info. The military 7.62X51 round was designed to duplicate 1950's era 30-06 performance, but in a shorter cartridge to be used in the M-14. Semi-autos need a fairly narrow range of pressures in order to operate reliably. Since the 1950's both 308 and 30-06 commercial loads have become much more powerful. Those civilian loads function just fine in bolt rifles, but military rifles were designed to operate at a specific pressure level that many commercial hunting loads exceed.