AR build issue

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  • jcjarmon
    Bloodstained
    • Dec 2016
    • 69

    #16
    Just because they make them, doesn't mean they work the same way they do in bolt guns. Ive never seen a 5r barrel, in an AR, at Camp Butner.

    Comment

    • StoneHendge
      Chieftain
      • May 2016
      • 2009

      #17
      Originally posted by jcjarmon View Post
      Just because they make them, doesn't mean they work the same way they do in bolt guns. Ive never seen a 5r barrel, in an AR, at Camp Butner.
      This 5r AR15 barrel works pretty good



      image.jpeg

      1x 2MOA red dot
      Let's go Brandon!

      Comment

      • slickshot223
        Unwashed
        • Apr 2017
        • 19

        #18
        Have checked the gas port, it is .094, some barrels use an .070 port with the MLGS, so I have increased the buffer weight from 5.1 oz to 5.5 oz, as opposed to an adjustable gas block, and will shoot it later today!!
        Last edited by slickshot223; 06-20-2017, 03:56 PM.

        Comment

        • Retro
          Warrior
          • Jul 2016
          • 150

          #19
          Thanks
          Originally posted by StoneHendge View Post
          Satern's muzzle device - it's on the rifle in this thread
          http://www.65grendel.com/forum/showt...E-Grendel-pr0n

          Comment

          • slickshot223
            Unwashed
            • Apr 2017
            • 19

            #20
            5.5 buffer installed!! Have shot three different loads, all about an inch!! Felt recoil seems to be less, however the ejected brass is thrown forward and close to the action about a foot with some of the empties falling next to the action! Thinking maybe a new extractor will help this!!Bolt is locked back after each load as it should!!
            Interesting find, if the magazine is retained to the last round, that last shot will go outside the group, this happened on every load!! Re-shooting the loads and dropping the magazine before firing the last round the shot stays with the group!!

            Comment

            • LRRPF52
              Super Moderator
              • Sep 2014
              • 8569

              #21
              Originally posted by slickshot223 View Post
              Ok, here we go, a friend has brought me his 6.5 Grendel that he can't seem to get shooting any better than 1 1/2 at 100 yrds!! The loads that are posted on some of the forums, along suggested loads from the manuals, with accuracy of 3/4 inch or less will absolutely not shoot in this rifle!! The barrel is a Stoner 1-8 twist 5R 18 inch SS. The assembly seems to be in good shape!! Have ask him to bring me some of the same loads he has been trying to see if I shoot any differently!! Results seem to be the same!( ya I know that doesn't mean much!!LOL) The fired brass has carbon residue on every fired case about half way back the brass! Compounded by FTF of one in 5-6 rounds fired!! With the carbon on the brass and the FTF one would think that the chamber pressure was lacking, but the loads used are all at the higher end of the suggested loads! The heads space checks as it should!!

              Now for some of the findings. When cleaning the barrel I find a loose area about an inch ahead of the gas block opening, the patch becomes loose as it passes that area then tightens again, then about the last inch and a half of the barrel the patch becomes much tighter than the rest of the barrel making one think the barrel is choked!
              Thoughts: the loose area maybe contributing to the carbon issue due to chamber pressure drop, as the gas fills the loose area, and may also contribute to the FTF issue!! The choking of the last portion of the barrel may be effecting the accuracy!!
              YOUR THOUGHTS????
              If you want top accuracy, I recommend bedding the barrel into the upper.

              You need adjustable gas on a lot of those barrels if the gas port is .094". It should be .076", no larger on an 18"/MLGS Grendel. That will help with FTFeed malfs since the cyclic rate right now is likely way too fast.

              For a lot of shooters who are used to bolt guns or .223 AR15s that don't really recoil much when you break the shot, there are some techniques you need to apply when driving a 6.5 Grendel to maintain a more solid position than you would when free-recoiling a rifle. Firm rearward pressure on the pistol grip pulling the butt into your chest/shoulder area and a rear bag help out a lot. 1.5" groups for shooters who aren't aware of some of the gas gun technique nuances is actually pretty good shooting.

              You didn't say what loads you were shooting. That data might be helpful to post.
              NRA Basic, Pistol, Rifle, Shotgun, RSO

              CCW, CQM, DM, Long Range Rifle Instructor

              6.5 Grendel Reloading Handbooks & chamber brushes can be found here:

              www.AR15buildbox.com

              Comment

              • LRRPF52
                Super Moderator
                • Sep 2014
                • 8569

                #22
                Originally posted by jcjarmon View Post
                First problem I see is the 5r barrel. Barrels with 5 rifling groves are fine in bolt guns. But not in gas operated ARs. When you bore the gas port, the hole lands in one of the 4 rifling. On a 5r barrel, that's not really doable. I bet whoever sold you that barrel, ether didn't know what they were talking about, or had the same problem your having, and just wanted to get rid of it. Thats why you'll never see a Krieger 5R Ar-15 barrel. There's no such thing.
                I've had several barrels installed on AR10s and AR15s using 5R that are some of the most accurate barrels I've ever owned, including Bartlein and Obermeyer.

                My .260 Rem gas gun with 5R Bartlein pipe is scary accurate, and a laser at 1000yds. First groups out of the gate with it were .6" (5rd) and just started shrinking down into the .4s.

                There are 6.5 Grendel Satern barrels chambered by AA I've shot that put 8 rounds into the .2s at 100yds. Bwaites has them, and they are boring to ring the IPSC flasher TGT with at 700yds.

                This is the first I've heard about 5R not being able to time with the gas port.
                NRA Basic, Pistol, Rifle, Shotgun, RSO

                CCW, CQM, DM, Long Range Rifle Instructor

                6.5 Grendel Reloading Handbooks & chamber brushes can be found here:

                www.AR15buildbox.com

                Comment

                • Kilco
                  Chieftain
                  • Jan 2016
                  • 1201

                  #23
                  My father's Armalite AR10 with a 24" 260 Rem Krieger barrel is 5r rifling and it functions perfectly. One of the most accurate gas guns I've ever shot.
                  Last edited by Kilco; 06-25-2017, 01:02 PM.

                  Comment

                  • Lastrites
                    Warrior
                    • Apr 2017
                    • 678

                    #24
                    Likely not the extractor and still over gassed with the brass going forward. Relenting to an adjustable gas block isn't a bad thing and is the one thing that may really help, but Klem and his words of wisdom are a valid consideration.

                    If there truly is a loose spot forward of the gas block that in itself should be remedied by the manufacture if your so inclined. You should see if the manufacture is up to the task of possible replacement.

                    Comment

                    • slickshot223
                      Unwashed
                      • Apr 2017
                      • 19

                      #25
                      Have ordered an adjustable gas block, LRRPF52 has advised the gas port is too large at .094!! Will be posting more info once the new part in on and functioning!! Appreciate ALL the help!! I is very obvious now that the action is over gassed!!

                      LRRPF2 ---the recoil on this thing is quit sharp, that was the very first observation, when shooting the first loads!!!!
                      Last edited by slickshot223; 06-26-2017, 07:21 PM.

                      Comment

                      • slickshot223
                        Unwashed
                        • Apr 2017
                        • 19

                        #26
                        This has been an interesting venture to say the least, adj. gas block added and the brass is still exiting forward of 3 o clock, but not as bad!! Have replaced the extractor spring assy!! Going to take the buffer to 6 oz. to see if it slows further! All loads have been with the 123 Hornady, powders 2460, H335, RL-15, 8208!

                        Recoil is not nearly as sharp as before!!

                        Comment

                        • LRRPF52
                          Super Moderator
                          • Sep 2014
                          • 8569

                          #27
                          Originally posted by slickshot223 View Post
                          Have ordered an adjustable gas block, LRRPF52 has advised the gas port is too large at .094!! Will be posting more info once the new part in on and functioning!! Appreciate ALL the help!! I is very obvious now that the action is over gassed!!

                          LRRPF2 ---the recoil on this thing is quit sharp, that was the very first observation, when shooting the first loads!!!!
                          If you feel sharp recoil in the 6.5 Grendel, it's probably overgassed. Even the lightweight 16" builds I've done are just pleasant little pussycats to shoot, especially the Lilja.
                          Last edited by LRRPF52; 08-09-2017, 12:17 AM.
                          NRA Basic, Pistol, Rifle, Shotgun, RSO

                          CCW, CQM, DM, Long Range Rifle Instructor

                          6.5 Grendel Reloading Handbooks & chamber brushes can be found here:

                          www.AR15buildbox.com

                          Comment

                          • slickshot223
                            Unwashed
                            • Apr 2017
                            • 19

                            #28
                            Well, have install the adjustable gas block, installed a 6 oz. buffer, fired 5 rounds two different loads, the brass is landing at 1:30 position and forward of the barrel, recoil is still very sharp!! Not sure where to go from here!! Thought sure this last change would calm this thing down, but no success!!

                            Comment

                            • funnelcake
                              Bloodstained
                              • Jun 2017
                              • 51

                              #29
                              Pretty sure Midway switched to BCA barrels for their AR Stoner line. Have you tried cranking the gas block until it's a "single shot" and adjusting out from there? I might have missed it...is it mid-length or rifle length gas?

                              Comment

                              • Lastrites
                                Warrior
                                • Apr 2017
                                • 678

                                #30
                                Forward bouncing brass, think it may be tagging the back edge of the ejection port as it is flipping out? Check to see how far the bcg manually will pull back, the face of the bolt should be forward of the back edge of the ejection port by like an 1/8" to 1/4" when you manually pull all the way back with the charging handle. If the face of the bolt disappears behind the back edge it will toss brass forward.

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