reamed liberty barrel groups.

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  • hydrotech
    Warrior
    • Sep 2014
    • 115

    reamed liberty barrel groups.

    Hey guys, I have a 18" liberty barrel that was shooting huge 3-4" groups, but now its shooting much tighter groups. I had the chamber re-reamed. I wanted to be able to load 123 SST mag length anyways. I have had this barrel for around a year and just got it put together on a rifle. Win748 didn't group well. However 28 and 28.3 grains 8208 XBR did pretty good with COAL of 2.290. This morning I shot a 1-3/4" 5 shot group, but 4 were within an inch. I was shooting with a bipod on a shooting table with a rear bag. Ya think I can tighten it up to 5 in an inch? I also have some H335 I have not tried but by looking at hornadys book it looks like it has less velocity than 8208. wondering if i should keep experimenting. this is going to be a hunting gun. Deer and coyotes. However I'd like to kill coyotes in open fields at 400 to 500 yards. how would an 1.75 inches at 100 group at 500? around 8-9 inches right?
    Attached Files
    Last edited by hydrotech; 11-04-2014, 02:59 PM.
  • LRRPF52
    Super Moderator
    • Sep 2014
    • 8569

    #2
    Is your upper receiver face lapped?

    Is the barrel bedded?

    If that throat has too much freebore, it will be hard to tighten up the groups. 2.290" is about as far as you want to go for mag-fed COL.
    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

    • hydrotech
      Warrior
      • Sep 2014
      • 115

      #3
      well it has a YHM free float tube on it....is that what ya meant by bedded? Mark at PF said i should try .04 to .06 jump to reduce pressure. At 2.290 I have .06 jump. This is my first grendel. it was a liberty group buy, i put it together, shot it....unhappy with it....sat on my bench....just got it chamber reamed and having another go with it. No the upper receiver face is not lapped.

      Comment

      • VASCAR2
        Chieftain
        • Mar 2011
        • 6219

        #4
        I think he means using blue Loctite on the barrel extension to bed the barrel into the upper receiver when your assembling your upper. Brownell's sells a tool to lap the face of the upper to ensure the barrel is sitting square in the upper before threading on the barrel nut. These steps sure don't hurt if your trying to squeeze all your barrels potential accuracy.

        I have used H-335 powder for 85 to 100 grain bullets and it has been accurate and clean burning. I haven't tried H-335 on 120-125 grain bullets and usually load CFE223 with that bullet weight.

        Comment

        • LRRPF52
          Super Moderator
          • Sep 2014
          • 8569

          #5
          Who re-reamed it, and what reamer did they use?
          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

          • hydrotech
            Warrior
            • Sep 2014
            • 115

            #6
            mark at PF did the $70 fix. Wish I'd spent the extra loot on a better quality barrel in the fist place, but what's done is done. I'll try it out on the homeplace in KY this weekend at my cousins, on whitetails. It's plenty good to take care of them at 100 yards...just wanting to tighten it up for long shots on 'yotes this winter after deer season. maybe a little more experimenting in order with the 123 SST.

            Comment

            • LRRPF52
              Super Moderator
              • Sep 2014
              • 8569

              #7
              Read up on accurizing the AR15, lapping the receiver face, bedding the barrel, optics mounting with balanced torque on the rings, correct torque on the rings (not destructive compression with inch pounds exceeding the recommended specs.

              Based on the Wheeler Fat-Wrench listing;

              Ring screws, Aluminum; 10-15 inch-lbs.
              Ring Screws; Steel; ..... 15-20 inch-lbs.

              I have seen several incidents where shooters have cranked down so hard, it crushed the scope tube and permanently damaged the optical housings.
              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

              • NugginFutz
                Chieftain
                • Aug 2013
                • 2622

                #8
                +1

                Wheeler F.A.T. wrench is your friend when it comes to mounting optics, etc. On days when I've eaten too many Wheaties I've gone over without knowing it. The F.A.T. wrench always gets it right. Cheap insurance, all around.
                If it's true that we are here to help others, then what exactly are the others here for?

                Comment

                • hydrotech
                  Warrior
                  • Sep 2014
                  • 115

                  #9
                  thanks

                  Comment

                  • Drifter
                    Chieftain
                    • Mar 2011
                    • 1662

                    #10
                    The only way to know how it will group at 500 yards is to shoot it. Groups at close range are not necessarily indicative of potential long range performance.

                    Also, try varying the seating depths with the SST's. They can shoot well with a jump, but you still need to experiment for best results. In other words, a COL shorter than mag length might perform better.
                    Drifter

                    Comment

                    • achristian8
                      Warrior
                      • Jun 2014
                      • 129

                      #11
                      These groups are from my 18inch liberty 5r. They are with 120 gr nosler ballistic tips with 26 gr Of benchmark. Coal 2.260. My gun does not do well with SST or amax bullets.
                      Attached Files
                      Adam

                      Comment

                      • pinzgauer
                        Warrior
                        • Mar 2011
                        • 440

                        #12
                        Originally posted by achristian8 View Post
                        These groups are from my 18inch liberty 5r. They are with 120 gr nosler ballistic tips with 26 gr Of benchmark. Coal 2.260. My gun does not do well with SST or amax bullets.
                        This to me is a bit telling about the throat wars as I've not seen a SAAMI throated grendel that did not like the AMAX and SST's. But at least you know what works!

                        Comment

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