Texas Gun Forum Ad
Page 1 of 2 12 LastLast
Results 1 to 10 of 11
  1. #1
    Member
    Join Date
    May 2009
    Location
    Fort Worth, Texas
    Posts
    95

    .270 win VS. .308 win

    Have any of yall ever wondered what made the military choose the .308 win over the .270 win. I recently started wondering that when I was messing around on the ballistic calculator on my phone I began comparing the ballistics of the .308 and the .270 to see what the how different conditionds effect the flight paths of the bullets. At first I was just using the best flying cartridges from both the .270 and .308,but then I decided to try the exact same cartridges. What I found was that the .270 had better ballistics as far as bullet drop and wind drift when put under the same conditions as the .308. Have any of yall wondered this or even know why the military doesn't use .270 over the .308?

  2. #2
    Event Coordinator High-Cap's Avatar
    Join Date
    Aug 2008
    Location
    ft worth/haslet tx
    Posts
    4,090
    because the military switched to the 308 after determining the .30-06 was too long, both as a cartridge and a rifle

    you can carry more .308 rounds than .30-06. the bullet is the same, but the brass and powder is less weight with the 308. the bolt rifles will be somewhat lighter as well, due to less metal in the bolt and action

    the 270 is a necked down .30-06 thats why it shoots flatter, there is more powder available. more powder capacity means more velocity, more velocity means it carries out to range with less drop...

    with the chambering of machine guns to shoot .308 the cyclic rate is a LOT faster because the bolt doesn't have to travel as far back as it would to chamber the .30-06 round...

    so more ammo capacity, faster shooting, and lighter equipment is why they use the .308 vs. the .270
    Builder of AR-15's, 1911's, DuraCoat finisher, and general gunsmith...PM or Email me for details.

    [SIGPIC][/SIGPIC]

  3. #3
    Internet Tough Guy Texas1911's Avatar
    Join Date
    Feb 2008
    Location
    Austin, TX
    Posts
    11,330
    .270 and .308 are significantly worse than other chamberings of the time. The average 130 gr. .270 round and 150 gr. .308 round are about as slick as a brick flying through the air, .30-06 was no better. The 8mm Mauser round was far superior, and the 6.5x55 Swede is probably the best military round ever to be fielded.

    .270 and .308 are only around because of politics and marketing ... as a caliber they both are crap.
    http://www.subaruwrxsti.org - Subaru WRX STI Information and Tuning Resource
    http://www.vikingspeedshop.com - Tuning Parts for Subarus and others.


  4. #4
    Event Coordinator High-Cap's Avatar
    Join Date
    Aug 2008
    Location
    ft worth/haslet tx
    Posts
    4,090
    Quote Originally Posted by Texas1911 View Post
    .270 and .308 are significantly worse than other chamberings of the time. The average 130 gr. .270 round and 150 gr. .308 round are about as slick as a brick flying through the air, .30-06 was no better. The 8mm Mauser round was far superior, and the 6.5x55 Swede is probably the best military round ever to be fielded.

    .270 and .308 are only around because of politics and marketing ... as a caliber they both are crap.
    270 has taken quite a few animals in my experience, and is a very capable hunting round... it isn't worth a darn for long range precision shooting, but as an inside 400 yd hunting round it does have alot of merit for terminal ballistics.


    i agree with you on the 6.5x55 cartridge, the high SD of the bullets coupled with high BC's make it a very effective round for both long range precision and taking big game (moose)

    i am thinking long and hard on the next 6.5 gun i build, either 6.5-06 or a 6.5wsm. i would try and revive the 264 win mag, but i don't want to go the belted route...
    Builder of AR-15's, 1911's, DuraCoat finisher, and general gunsmith...PM or Email me for details.

    [SIGPIC][/SIGPIC]

  5. #5
    Internet Tough Guy Texas1911's Avatar
    Join Date
    Feb 2008
    Location
    Austin, TX
    Posts
    11,330
    Quote Originally Posted by High-Cap View Post
    270 has taken quite a few animals in my experience, and is a very capable hunting round... it isn't worth a darn for long range precision shooting, but as an inside 400 yd hunting round it does have alot of merit for terminal ballistics.

    i agree with you on the 6.5x55 cartridge, the high SD of the bullets coupled with high BC's make it a very effective round for both long range precision and taking big game (moose)

    i am thinking long and hard on the next 6.5 gun i build, either 6.5-06 or a 6.5wsm. i would try and revive the 264 win mag, but i don't want to go the belted route...
    Let's face it ... just about anything with good shot placement is going to drop game in this area of the world, and humans aren't exactly hardy animals.
    http://www.subaruwrxsti.org - Subaru WRX STI Information and Tuning Resource
    http://www.vikingspeedshop.com - Tuning Parts for Subarus and others.


  6. #6
    Event Coordinator High-Cap's Avatar
    Join Date
    Aug 2008
    Location
    ft worth/haslet tx
    Posts
    4,090
    yeah true...

    i guess since my shots are 99% of the time in the boiler room, doesn't really matter what you shoot em with.
    Builder of AR-15's, 1911's, DuraCoat finisher, and general gunsmith...PM or Email me for details.

    [SIGPIC][/SIGPIC]

  7. #7
    TGT Supporter
    Join Date
    May 2009
    Location
    Leander(NW Austin)
    Posts
    1,730
    I am sure nato also had some influence. Many european firearms manufacturers started building .308s around the same time.

  8. #8
    Event Coordinator High-Cap's Avatar
    Join Date
    Aug 2008
    Location
    ft worth/haslet tx
    Posts
    4,090
    Quote Originally Posted by TexMex247 View Post
    I am sure nato also had some influence. Many european firearms manufacturers started building .308s around the same time.
    The .308 Winchester is a rifle round and is the commercial version of the military 7.62x51mm NATO centerfire cartridge. The .308 Winchester was introduced in 1952, two years prior to the NATO adoption of the 7.62x51mm NATO T65. Winchester (a subsidiary of Olin Corporation) branded the cartridge and introduced it to the commercial hunting market as the .308 Winchester. Winchester's Model 70 and Model 88 rifles were subsequently chambered for the new cartridge. Since then, the .308 Winchester has become the most popular short-action, big-game hunting cartridge worldwide.[1] It is also commonly used for civilian target shooting, military sniping, and police sharpshooting. The relatively short case makes the .308 Winchester especially well adapted for short action rifles.
    kinda funny it started life as a hunting round...but ballistically there are far superior options out there.
    Builder of AR-15's, 1911's, DuraCoat finisher, and general gunsmith...PM or Email me for details.

    [SIGPIC][/SIGPIC]

  9. #9
    Internet Tough Guy Texas1911's Avatar
    Join Date
    Feb 2008
    Location
    Austin, TX
    Posts
    11,330
    We adopted .308 and forced it down NATO's throat, ergo 7.62x51 NATO, the proliferation of the FAL, G3, etc.
    http://www.subaruwrxsti.org - Subaru WRX STI Information and Tuning Resource
    http://www.vikingspeedshop.com - Tuning Parts for Subarus and others.


  10. #10
    Member
    Join Date
    May 2010
    Location
    Fort Worth
    Posts
    76
    Quote Originally Posted by High-Cap View Post
    because the military switched to the 308 after determining the .30-06 was too long, both as a cartridge and a rifle

    you can carry more .308 rounds than .30-06. the bullet is the same, but the brass and powder is less weight with the 308. the bolt rifles will be somewhat lighter as well, due to less metal in the bolt and action

    the 270 is a necked down .30-06 thats why it shoots flatter, there is more powder available. more powder capacity means more velocity, more velocity means it carries out to range with less drop...

    with the chambering of machine guns to shoot .308 the cyclic rate is a LOT faster because the bolt doesn't have to travel as far back as it would to chamber the .30-06 round...

    so more ammo capacity, faster shooting, and lighter equipment is why they use the .308 vs. the .270
    Those are also the same reasons that the military went with the 5.56 over the .308 when it adopted the AR.

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


About Texas Gun Talk

    Texas Gun Talk is the most active and largest Texas gun forum on the net. Be sure to check out our gun classifieds, political, and hometown sections.

Quick Links

Follow us on

Twitter Facebook youtube

Back to Top
Google+