My love for this round is fading

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  • bwaites
    Moderator
    • Mar 2011
    • 4445

    #16
    Originally posted by LR1955 View Post
    Bill:

    Loads are too hot is all. I have seen this numerous times at High Power matches. A couple go right in the middle and the next blows up about 100 yards down range. Couple more go right in the middle and another one blows up. Simply put, the load is too hot for the bullet you are shooting.

    LR55
    The first time it happened, I thought the same, especially because I was shooting Berger hunting VLD's which have a thinner jacket. But I shot them crazy good over the same load for at least 100 rounds to start. But when I switched to target VLD's it happened also, so I spent some time talking with Bob and he told me about the carbon ring. Once I got it cleaned out per his instructions, it went back to little groups. You saw how it shot at Boomershoot. So now I keep it cleaned up, and generally, the first shot goes dead on and so do the rest.

    Comment

    • 1911man
      Warrior
      • May 2015
      • 482

      #17
      I am going to go ahead and dis-assemble everything and re-assemble it. I dont believe it is the scope as I have had this scope on several ARs and it has held tight and functioned well on each of them. However I am going to go ahead and swap it for one with a little more magnification so I can see my hits better and determine which shot in the sequence is the flyer. I am hoping Bwaites gas theory is the answer as that will be easy for me to fix.

      Comment

      • 1911man
        Warrior
        • May 2015
        • 482

        #18
        Originally posted by GatewayShepherd View Post
        You weren't kidding, those groups look exactly like the groups I have been having only slightly better.

        Comment

        • GatewayShepherd
          Unwashed
          • Jul 2015
          • 14

          #19
          Well…in the process of trying to eliminate some variables that may be causing the issues…I pretty much did the same thing. I took the entire upper apart, looked everything over and bedded the barrel extension in the receiver…and then in the process…put the American Defense Recon mount/scope back on the gun and realized the turrets weren’t lined up right? WTH? Earlier today while at the range I thought the scope had slipped in the rings. I had just put the gun up on the bags and pre leveled it and looked down thru the scope to realize that i thought I had the gun leveled..but the reticle was canted. Put the gun down on the concrete patio and used a distant building for a vertical line and brought the reticle back into plumb….or so I thought. What I now realized was that the etched glass had cut loose previous to that. When I remounted the scope..I realized the turrets were now off kilter. Sure enough..with the gun leveled on the shop bench…and the turret caps leveled..the reticle was 4.5 degrees off from plumb. When I had moved it earlier today…I didn’t have all my tools with me..so I used the distant building as a vertical plumb line..but never paid any attention to where the turrets were positioned. I thought that the scope had a very critical eye box and head position seemed to be very important in order to see clearly…but now I wondering if things weren’t screwed up from the get go.

          Comment

          • rabiddawg
            Chieftain
            • Feb 2013
            • 1664

            #20
            Originally posted by GatewayShepherd View Post
            Well…in the process of trying to eliminate some variables that may be causing the issues…I pretty much did the same thing. I took the entire upper apart, looked everything over and bedded the barrel extension in the receiver…and then in the process…put the American Defense Recon mount/scope back on the gun and realized the turrets weren’t lined up right? WTH? Earlier today while at the range I thought the scope had slipped in the rings. I had just put the gun up on the bags and pre leveled it and looked down thru the scope to realize that i thought I had the gun leveled..but the reticle was canted. Put the gun down on the concrete patio and used a distant building for a vertical line and brought the reticle back into plumb….or so I thought. What I now realized was that the etched glass had cut loose previous to that. When I remounted the scope..I realized the turrets were now off kilter. Sure enough..with the gun leveled on the shop bench…and the turret caps leveled..the reticle was 4.5 degrees off from plumb. When I had moved it earlier today…I didn’t have all my tools with me..so I used the distant building as a vertical plumb line..but never paid any attention to where the turrets were positioned. I thought that the scope had a very critical eye box and head position seemed to be very important in order to see clearly…but now I wondering if things weren’t screwed up from the get go.
            I have had the same thing happen to me.

            I have noticed also that canted crosshairs wont track properly when trying to zero the scope.
            Knowing everthing isnt as important as knowing where to find it.

            Mark Twain

            http://www.65grendel.com/forum/showt...2-Yd-Whitetail

            Comment

            • Klem
              Chieftain
              • Aug 2013
              • 3507

              #21
              1911,

              Was waiting to see if any other poster had more clarity on your problem.

              My two cents... if an AR15 barrel is giving you 3/4" 4-rd groups and occasionally 1" groups then maybe there is no problem. Maybe your re-loading is fine and that barrel is giving as good at it can. Some manufacturers claim 'sub-MOA' out-of-the-box for bolt action rifles using only 3-rd groups. 3/4-1MOA for 4 round groups from an AR15 is pretty good in my book.

              There are a few posters here who claim regularly smaller groups but I can only achieve some of the accuracy claims here with match-grade bolt guns.

              Comment

              • 37L1
                Warrior
                • Jan 2015
                • 273

                #22
                Originally posted by Klem View Post
                1911,

                Was waiting to see if any other poster had more clarity on your problem.

                My two cents... if an AR15 barrel is giving you 3/4" 4-rd groups and occasionally 1" groups then maybe there is no problem. Maybe your re-loading is fine and that barrel is giving as good at it can. Some manufacturers claim 'sub-MOA' out-of-the-box for bolt action rifles using only 3-rd groups. 3/4-1MOA for 4 round groups from an AR15 is pretty good in my book.

                There are a few posters here who claim regularly smaller groups but I can only achieve some of the accuracy claims here with match-grade bolt guns.
                This ^^^^

                Three or four holes touching and one or 2 out at 100 or 200 is pretty good for any AR. Maybe we are trying too hard to put 5 in 1 all the live long day. Maybe I shouldn't be frustrated with consistent .5 and .75 moa groups at 200 after all and know that I will hit whatever I'm aiming at?

                Comment

                • montana
                  Chieftain
                  • Jun 2011
                  • 3209

                  #23
                  There are days I shoot exceptionally good and other days I need to stay home. It doesn't matter if I'm competing in practical shooting, multi gun, shooting my custom bolt gun or my AR Grendel rifles. I'm not always able to shoot regularly because of work and family but one truth I know is shooting is a perishable skill. I have shot horrible groups on days that I would have sworn was a firearm or ammunition problem only to go back the next day with the same firearm and ammunition and shoot outstanding groups. It's not always easy to admit but on many occasions my shooting just out right sucks.

                  Comment

                  • kmon
                    Chieftain
                    • Feb 2015
                    • 2095

                    #24
                    ^^^^^^^^^^^^^

                    I do not get to shoot nearly as much these days as in the past but even when shooting regularly some days were much better than others. When working up loads for accuracy I take one of the rifles with loads of known very good accuracy to measure how I am shooting that day. Some days I am more on my game than others.

                    Comment

                    • NugginFutz
                      Chieftain
                      • Aug 2013
                      • 2622

                      #25
                      1911man,

                      I have a BHW in 5.56 that did pretty much what you're describing. Shot crazy small bug hole groups with 55 NBT's for a long time. Beginning one weekend, the groups started opening up and sometimes the POI would shift. I initially thought that my optics had gone bad (rare but not unheard of, on 5.56) and had Nikon look into it. While they did that, I tried another scope and met with similar results. Ultimately, it turned out to be a problem with the barrel to upper interface. I 'd changed hand guards a month or two before the trouble started, and apparently had not done a good job of seating while torquing it down. I bedded the barrel and did the 3-pass sneak up on it torquing, this time, and it's now back to shooting tiny groups.

                      Something to consider.
                      If it's true that we are here to help others, then what exactly are the others here for?

                      Comment

                      • 1911man
                        Warrior
                        • May 2015
                        • 482

                        #26
                        Originally posted by NugginFutz View Post
                        1911man,

                        I have a BHW in 5.56 that did pretty much what you're describing. Shot crazy small bug hole groups with 55 NBT's for a long time. Beginning one weekend, the groups started opening up and sometimes the POI would shift. I initially thought that my optics had gone bad (rare but not unheard of, on 5.56) and had Nikon look into it. While they did that, I tried another scope and met with similar results. Ultimately, it turned out to be a problem with the barrel to upper interface. I 'd changed hand guards a month or two before the trouble started, and apparently had not done a good job of seating while torquing it down. I bedded the barrel and did the 3-pass sneak up on it torquing, this time, and it's now back to shooting tiny groups.

                        Something to consider.
                        Thank you for that info. This is definitely something I considered. The problem I have with the idea that the barrrel needs re-torqued is the style of barrel nut I have is one where you have to align the hole with the gas tube and reciever. If I tighten down any more or less it the gas tube will not line up. It is torqued down to spec and everything lines up which makes me think that shouldn't be the problem.

                        Comment

                        • bwaites
                          Moderator
                          • Mar 2011
                          • 4445

                          #27
                          Little tiny things can make huge differences. I recently was at a steel match where one of the shooters suddenly found that ammo he had hand loaded was not chambering. He had used the same procedure on the entire batch, and he had run it all through a chamber gauge before coming to the match. About every 6-7 rounds he would have a round that simply refused to chamber. He was very concerned because he had loaded about 5000 similar rounds.

                          When he got home, he started checking the rounds and they gauged just fine. He remembered that he had a second chamber gauge and pulled it out. Those suspect rounds would not chamber in the new gauge. He started comparing the gauges, and there was .002 difference in the gauges. His barrel would chamber anything from the second gauge, but not everything that would go in the first gauge.

                          My point is that VERY small differences will have hugely disparate results. Sometimes our AR 15 Legos have very small, almost impossibly small differences, but it will make a big difference in how they shoot. Go slow, line everything up, make sure the face of the receiver is square, and you are usually good to go!

                          Comment

                          • rwh
                            Warrior
                            • Jun 2014
                            • 188

                            #28
                            I had a similar experience with accuracy dropping off shooting 8208XBR in my rifle. I shoot hBN coated 123 gr scenars over 27.8 gr of 8208XBR with BR4 primers. This isn't a max load but it gave me the best 20 shot groups so I went with it. After a couple hundred rounds my primers started to flatten and I started getting fliers. I have a bore scope and it showed that I had carbon buildup in the first couple of inches in the barrel. This was hard carbon, not powder residue. I used JB bore paste to clean the barrel down to the metal and accuracy improved. I've found that I need to clean with a bronze brush at least once every 100 rounds to keep the carbon buildup under control. I also use JB every 500 rounds to make sure nothing is building up.

                            Comment

                            • bwaites
                              Moderator
                              • Mar 2011
                              • 4445

                              #29
                              Originally posted by rwh View Post
                              I had a similar experience with accuracy dropping off shooting 8208XBR in my rifle. I shoot hBN coated 123 gr scenars over 27.8 gr of 8208XBR with BR4 primers. This isn't a max load but it gave me the best 20 shot groups so I went with it. After a couple hundred rounds my primers started to flatten and I started getting fliers. I have a bore scope and it showed that I had carbon buildup in the first couple of inches in the barrel. This was hard carbon, not powder residue. I used JB bore paste to clean the barrel down to the metal and accuracy improved. I've found that I need to clean with a bronze brush at least once every 100 rounds to keep the carbon buildup under control. I also use JB every 500 rounds to make sure nothing is building up.
                              This is essentially what happpened with my 7mm WSM, and its what I do to keep it clean as well. stokesrj was that one who helped me figure out what was happening. Its less common in the lower pressure rounds, but I think it may be related to how the barrels are made. I haven't had it happen in a cut barrel, but have in 2 button barrels. It might be that hand lapped barrels have less problems as well.

                              Comment

                              • 1911man
                                Warrior
                                • May 2015
                                • 482

                                #30
                                All right, I have some more data to add to this mystery. I ordered the Brownells tool to square the face of my receiver and I am planning on bedding the barrel as well. I also bought an adjustable gas block. However, those tools/parts did not come in before my trip to my land on Sunday so I had to make due with what I had. I installed a new bolt carrier group that I had laying around for another build to see if I could eliminate anything bolt related.I think re-torqued the barrel nut and cleaned/re-installed the gas tube and block. My last piece to add was a different scope so I can zoom in more to see where each shot is landing. It is a Vortex Viper 6.5-20x that I have had for years and put on several different rifles.

                                So I fired a couple of rounds to foul the bore and then proceeded to shoot my first 5 shot group with a cool but fouled barrel. The first shot landed wide and then the next 4 landed on top of one another. The 4 shots measure under 1/2 Inch. I wait 20 minutes, shoot another string and same thing. So I switch to another load to see if it makes a difference. This load is with 28.5 grains of TAC and the same 120 SMK Bullet. Same exact thing only with the 4 shot cluster being 1/3 of an inch. First shot landed wide then the next 4 are in the same hole. So then I start thinking maybe the barrel is too cold, maybe I am letting it cool too much between shots. So I get 6 rounds of my XBR load. I shoot the first shot off the paper, then I shoot the next five as if they were the only 5 I had and bam they all land in a nice cluster. It measures .443". Then I do it again and the 5 shot group measures .611". I do it again with the 28.5 TAC load and the 5 shot group measures .673". Then I do it with the 27.5 TAC load and the group measures .541" These are all 5 shot groups where I took 6 rounds and just shot the first one off paper.

                                Can anyone explain this craziness? I am starting to think its me and I have some sort of crazy mental block that wont allow me to successfully shoot the first round. I will post pictures of the groups when I get home from work this evening.

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