The Firing Line Forums

Go Back   The Firing Line Forums > The Hide > The Art of the Rifle: General

Reply
 
Thread Tools
Old December 15, 2009, 04:24 PM   #1
Departed402
Senior Member
 
Join Date: September 25, 2009
Location: Nebraska
Posts: 865
Are there battle rifles designed for .308 (not 7.62)?

Okay recently I've started a few posts about .308 and 7.62 NATO, and rifles that shoot them. I'm come to the conclusion that since rifles designed for .308 Win are made to withstand more pressure than rifles designed for 7.62, I should try to find a semi-auto rifle that is made for the specs for the .308, and not the 7.62.

So what are some (widely recognized/not overly expensive/reliable) military grade (semi-auto) rifles chambered for .308? (not 7.62, whose bullets harder to get anyway)
__________________
Slow is Smooth. Smooth is Fast.
Departed402 is offline  
Old December 15, 2009, 05:27 PM   #2
Jimro
Senior Member
 
Join Date: October 18, 2006
Posts: 5,773
Saiga.

Seriously though, the pressure difference is a non-issue. The whole rigamaroll started when someone didn't convert CUP to PSI. When you measure them the same way they fall within range of each other.

Jimro
__________________
"Gorsh" said Goofy as secondary explosions racked the beaten zone, "Did I do that?"

http://randomthoughtsandguns.blogspot.com/
Jimro is offline  
Old December 15, 2009, 05:34 PM   #3
Jimro
Senior Member
 
Join Date: October 18, 2006
Posts: 5,773
Big Stick,

Yes, there is no way to convert CUP to PSI accurately. What you have to do is measure both. What happened was that the Gubmint measured the 7.62x51 in CUP and somewhere along the line someone typed "PSI" behind that measurement. The 308 has a SAAMI spec in PSI, which caused the whole "pressure difference" argument.

Jimro
__________________
"Gorsh" said Goofy as secondary explosions racked the beaten zone, "Did I do that?"

http://randomthoughtsandguns.blogspot.com/
Jimro is offline  
Old December 15, 2009, 05:38 PM   #4
ranger dave
Senior Member
 
Join Date: November 25, 2005
Posts: 485
7.62x51

7.62x51 is 308 win its all in the name any rifle you pick up marked 7.62 nato will fire the 308 win round. sammi and nato spec. are very close on max pressure for each round. with nato being just a bit higher.
ranger dave is offline  
Old December 15, 2009, 05:45 PM   #5
azredhawk44
Junior member
 
Join Date: September 28, 2005
Location: Mesa, AZ
Posts: 6,465
Quote:
Okay recently I've started a few posts about .308 and 7.62 NATO, and rifles that shoot them. I'm come to the conclusion that since rifles designed for .308 Win are made to withstand more pressure than rifles designed for 7.62, I should try to find a semi-auto rifle that is made for the specs for the .308, and not the 7.62.
Pressure is a non-issue.

The key difference is maximum headspace. And really, only in machine guns.

A secondary difference is brass wall thickness. The 7.62NATO has thicker brass than .308 winchester.

7.62NATO ammo can be used in .308 rifles, and .308 ammo can be used in 7.62NATO rifles.

Long time M14 marksmen at Camp Perry and other competitions will use .308 commercial brass in order to get more case volume and velocity while still staying within the pressure limits of the M14 gas system.

7.62NATO has more to do with the CHAMBER of a rifle than the ammunition put in it.
azredhawk44 is offline  
Old December 15, 2009, 05:58 PM   #6
azredhawk44
Junior member
 
Join Date: September 28, 2005
Location: Mesa, AZ
Posts: 6,465
Quote:
I should try to find a semi-auto rifle that is made for the specs for the .308, and not the 7.62.
"made for the specs for the .308" makes me wonder if you are concerned about the limitations on ammunition for .308 ammo in M14 and other rifles.

Firstly:
-You won't find hunting ammunition in 7.62NATO.
-You have strict propellant controls on 7.62NATO ammunition.
-You have perhaps 3 different projectiles available for 7.62NATO (150gr FMJ, 175gr BTHP, ???gr tracer).

-.308 ammo is sold in bullet weights from 125gr to 200gr.
-.308 ammo is sold using vastly different propellants.

The M1 Garand is stamped for .30-06 ammunition, but that doesn't mean you can just stuff any old .30-06 cartridge in it and expect it to work fine, either.

The wide variety of retail ammunition dictates that a rifleman know his ammunition.

Springfield M1A rifles tend to be headspaced at 1.635" or very close to it. This is a happy place that will reliably chamber .308 Winchester as well as 7.62NATO rounds.

The reason for 7.62NATO chambers accepting longer total headspace is for SLOP, not PRECISION. Hot machine gun chambers, linked ammo dragging in the dirt, things like that.

This won't be an issue with a semiautomatic box-fed rifle, probably. Tighter chambers produce superior accuracy.



Note that the OAL is the same, but the key measurement difference is in the top of the case shoulder: 1.714 on NATO and 1.712 on .308. Headspace is measured from the middle of the shoulder.
azredhawk44 is offline  
Old December 15, 2009, 08:36 PM   #7
MHbushmaster
Senior Member
 
Join Date: January 25, 2007
Location: near Rochester, NY
Posts: 116
To the OP, yes there are battle rifles designed for .308 and will function just fine with them.

Check out DSA, they have FAL's which will meet your needs for a battle rifle that will function with .308 AND 7.62x51mm (M80 ball).

FAL's are great battle rifles. M1A's are great if your sitting on a rifle range, they are very accurate. I like the adjustable gas settings on the FAL, the left handed charging handle and left handed bolt release as well as the safety (not in the trigger guard).
MHbushmaster is offline  
Old December 15, 2009, 10:46 PM   #8
ranger dave
Senior Member
 
Join Date: November 25, 2005
Posts: 485
like i said 308 is 7.62x51

most people know that you cant get nato ammo with soft points. nato ammo is all over the place. lets face it. its not ment to sniper ammo. most is good for 3 m.o.a. at best most poeple dont ever talk about the bigest differents there is in nato ammo crimped in primers
ranger dave is offline  
Old December 15, 2009, 11:12 PM   #9
pvt.Long
Senior Member
 
Join Date: March 7, 2009
Posts: 433
Ill put my money on the m14 and m1a rifles. They have a customizable gas system. They have m14 rifles beeing dusted off and oild as long range rifles. With mil surp you will just find that ammo produced to military specs and standards. 308 is more of a civilian round that has more varieties for civilian applications like hunting. azredhawk44s diagram shows that the 7.62 nato is a larger round but for rifles there isnt a bit of difference between the two Ive shot steel core current production tracer rounds and vintege fmjs and steel jacketed rounds produced in the 90s as well steel cased Russian import and top dollar hunting rounds. I get the same performance out of all the rounds useing my old vet m14. some are just more fun to shoot especially at night and at old cars.
pvt.Long is offline  
Old December 16, 2009, 08:00 AM   #10
wogpotter
Senior Member
 
Join Date: September 27, 2004
Posts: 3,433
Quote:
Ill put my money on the m14 and m1a rifles. They have a customizable gas system.
Where?
I've found aftermarket conversion kits for the gas plug to make it customizable, but never, ever heard of a factory fitted one?
wogpotter is offline  
Old December 16, 2009, 08:06 AM   #11
J.Kendall
Member
 
Join Date: November 9, 2009
Location: Michigan
Posts: 40
One of the new SCAR rifles is chambered for .308 (7.62x51). Too bad it costs an arm and a leg.
__________________
One of the NRA's newest members
J.Kendall is offline  
Old December 16, 2009, 08:53 AM   #12
fyimo
Senior Member
 
Join Date: November 6, 2009
Posts: 360
In Vietnam the Army used M14's as a sniper rifle and they provided match ammo for it.
fyimo is offline  
Old December 16, 2009, 09:59 AM   #13
azredhawk44
Junior member
 
Join Date: September 28, 2005
Location: Mesa, AZ
Posts: 6,465
Quote:
azredhawk44s diagram shows that the 7.62 nato is a larger round but for rifles there isnt a bit of difference between the two
Please point out where on the diagram, the NATO round is larger than the Winchester round...

There is only 1 dimensional difference I can find, and that is the 1.712/1.714 (NATO being longer) dimension to the top of the shoulder.

That's directly attributable to the need for a sloppier chamber in machine guns, to accommodate lightly dented cases, dirty cases, filth and blowback.
azredhawk44 is offline  
Old December 16, 2009, 10:05 AM   #14
Departed402
Senior Member
 
Join Date: September 25, 2009
Location: Nebraska
Posts: 865
I would like to thank everyone for their input, especially those who reassured me that .308 pressure and 7.62 pressure is an non-issue. I am one to error on the side of caution, and since there is a handful of people that believe 7.62 and .308 aren't interchangable I wanted to check into it more.

Thanks
__________________
Slow is Smooth. Smooth is Fast.
Departed402 is offline  
Old December 16, 2009, 12:12 PM   #15
noyes
Senior Member
 
Join Date: December 27, 2008
Posts: 1,032
locking shoulder

chamber
noyes is offline  
Reply

Tags
.308 , 7.62x39

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 01:00 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2014 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Contact Us
Page generated in 0.08982 seconds with 7 queries