• If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Announcement

Collapse
No announcement yet.

Copper or Bi-metal projectiles & Brass vs. Steel Cases.

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • Copper or Bi-metal projectiles & Brass vs. Steel Cases.

    Interesting info, wear patterns, service life and rate of malfunctions, etc:

    http://www.luckygunner.com/labs/bras...el-cased-ammo/

    I have found little or no problems with either type of 7.62x39 ammo, no burn rate issues or stuck cases, but this article is based on 556/223 ammo testing.
    KMA - member #07
    Read This ~ Click Here!




    sigpic

  • #2
    Wow, they really put them through the ringer. Good information.
    "For I know the plans I have for you," declares the LORD, "plans to prosper you and not to harm you, plans to give you hope and a future." - Jeremiah 29:11

    Comment


    • #3
      Their basic premise was that, even factoring in the costs of replacement barrels, the steel cased / steel jacketed ammo is a bargain.

      Maybe it is - for plinking.

      But, I don't think I'd want to be stocking it for SHTF.

      Even leaving aside diminished terminal effects and possible fouling issues, the greatly increased barrel wear would discourage me from stocking it in .223/5.56.

      But, that's just IMHO, and YMMV.
      KGC - member #04

      Comment


      • #4
        Did anyone notice the disturbing level of gas port erosion that the brass cased Federal caused? The pictures are included in the above article link.
        Either ammo type seemed to cause more wear (just different types) than 10k rounds should, seems the barrels would stand up better than that.
        Then again, they did pretty much stand on them (firing as fast as they could = standing on the trigger, shooting style), but still...only 10k rounds,
        before that level of abuse to the barrels?

        KMA - KGC - THA - #01
        Owner:
        www.WarRifles.com



        '308 Holes Make Invisible Souls'

        'The Path of Excess Leads to the Palace of Wisdom'

        'Crush Your Enemies, See Them Driven Before You, Hear the Lamentations of their Women'



        You cannot invade mainland America.
        There would be a rifle behind every blade of grass.

        Isoroku Yamamoto, Japanese Admiral

        Comment


        • #5
          The port erosion was likely caused by a combination of the higher port pressure with the Federal ammo, high temperatures caused by the prolonged rapid fire, and the type/grade of steel used in the Bushmaster barrels.

          The same heat and steel issues also contributed to rapid wear seen with the steel jacketed ammo.

          Originally posted by Briansammo View Post
          Did anyone notice the disturbing level of gas port erosion that the brass cased Federal caused? The pictures are included in the above article link.
          Either ammo type seemed to cause more wear (just different types) than 10k rounds should, seems the barrels would stand up better than that.
          Then again, they did pretty much stand on them (firing as fast as they could = standing on the trigger, shooting style), but still...only 10k rounds,
          before that level of abuse to the barrels?

          KGC - member #04

          Comment


          • #6
            The higher gas port erosion with the federal ammo was because the bore was still in good shape, allowing a decent amount of port pressure. The wolf, tula had so shot out the bore that a lot of pressure was lost around the bullet. causing less gas cutting at the port.

            Comment


            • #7
              So,
              What kind of barrel life should a
              non-damn-near-full-auto-for-10K-rounds-straight
              AR15 owner expect out of a good milspec barrel?


              After all, real life use would be methodical, aimed shots not Bllllllaaaaaaaaarrrrrraaap! Reload M'Fer - Bllllllaaaaaaaaarrrrrraaap!
              KMA - KGC - THA - #01
              Owner:
              www.WarRifles.com



              '308 Holes Make Invisible Souls'

              'The Path of Excess Leads to the Palace of Wisdom'

              'Crush Your Enemies, See Them Driven Before You, Hear the Lamentations of their Women'



              You cannot invade mainland America.
              There would be a rifle behind every blade of grass.

              Isoroku Yamamoto, Japanese Admiral

              Comment


              • #8
                As has been said, Serious competitive shooters tend to replace their barrels every 4000-5000 rounds - although this is intentionally BEFORE accuracy can even begin to degrade, as these are competition guns and only the best possible accuracy is acceptable. I think this is a good quote with a valid opinion; "Pat Rogers has about 45k rounds on "Filthy 14", a BCM midlength, and it's still going strong in his carbine classes. He hasn't noticed any increase in group size but he's not using it for precision shooting at 600 yards either. I think 40-50k is a reasonable expectation for a chrome-lined barrel that's not being subjected to full-auto fire."

                That said, spare barrels are inexpensive compared to a case of ammo, and replacing them is easy.

                Comment


                • #9
                  Originally posted by Briansammo View Post
                  So,
                  What kind of barrel life should a
                  non-damn-near-full-auto-for-10K-rounds-straight
                  AR15 owner expect out of a good milspec barrel?


                  After all, real life use would be methodical, aimed shots not Bllllllaaaaaaaaarrrrrraaap! Reload M'Fer - Bllllllaaaaaaaaarrrrrraaap!
                  I use Bimetal Silver Bear .223 out of my bump fire AR & it was accurate for a while but with about 2000 rds down range. It won't hit an 18" gong at 100yds. Most of all the rounds through this rifle was bumped using a 30 or 100 round mags so it wasn't easy on the barrel.
                  I expected the barrel to wear but not this fast, I would guess the heat had something to do with it. It still bumps so until they make the stock illegal or I burn through the last of the 1500 rounds I have left this barrel will stay on this gun.

                  Comment


                  • #10
                    Originally posted by AK Shooter View Post

                    I use Bimetal Silver Bear .223 out of my bump fire AR & it was accurate for a while but with about 2000 rds down range. It won't hit an 18" gong at 100yds. Most of all the rounds through this rifle was bumped using a 30 or 100 round mags so it wasn't easy on the barrel.
                    I expected the barrel to wear but not this fast, I would guess the heat had something to do with it. It still bumps so until they make the stock illegal or I burn through the last of the 1500 rounds I have left this barrel will stay on this gun.
                    What type of barrel? Some manufacturers use 4140 or plain 4150 steels - chrome lined or unlined - in their AR's, rather than the chrome lined 4150 CMV called for in the TDP (aka 'MilSpec').

                    For most people, 4140 or plain 4150 steels is fine, and unlined barrels tend to be more accurate than chrome lined. However, these barrels are not designed to hold up to repeated full auto rates of fire - and will rapidly wear out. Stainless Steel barrels will wear even faster under those conditions.

                    KGC - member #04

                    Comment

                    Working...
                    X