OK, I was out today working up some .223 precision handloads through my Larue Stealth 18" AR (SS, 1/8, Wylde chamber). It was my 1st set of handloads through the gun. Previously, me and the rifle had been fairly consistantly 3/4 or so MOA running Black Hills 77 grn factory loads.
SO my issue is I'm getting what I consider excessive shifts in POI on every 1st shot in each 5 shot string. The 1st one I attributed to a "cold" barrel. But it wasn't really cold as I warmed up on some factory stuff (about 20 rounds) before shooting my load development handloads. So the barrel was still warm. I shot 10 five shot strings in all and eEVERY single 1st shot was almost exactly 3 MOA low and centered in the horizontal. String #2 did the same thing, even thought I waited max of maybe 5 min to shoot the 2nd string - so the barrel was still pretty hot to the touch. I sped the next string up to see if it re-occured and sure enough, 1st shot 3 MOA low and then the next 4 would group pretty nicely in the bull. So I sped up up even more, essentially waiting as long as it took me to pick up the previous 5 brass, load a new mag of 5 and sit down to shoot. Maybe 2-3 min. It didn't matter, still 1st shot about 3 MOA low, next 4 decent group. At this point the barrel was too hot to even touch when I began a new string, so the the whole idea of a "cold" barrel was RTFO.
I even noticed a distinct difference in POI if I waited more than about 45-60 secs between shots. If I waited just that amount, the next shot would diverge from the group pretty significantly. To test that out, in one string I shot the normal 1st shot that fell 3 MOA low, waited about a min and #2 fell about 1.5 MOA low, and then the next three were touching. So the bullets seemed to be climbing the ladder until the barrel was REALLY hot and then they settled down.
I don't recall it shooting this badly with the factory match stuff. I would usually get a no kidding cold barrel shot low, but then after that all the strings would be normal unless an excessive amount of time elapsed.
I figured it could be the handloads - but the chrono is showing good ES and SDs (SDs in the mid teens) - so I don't think I'm putting together shitty ammo. I'm using 77grn SMKs, properly prepped LC08 once fired brass, and two groups of powder (TAC and IMR 4895) to compare to each other. ALL loads were weighed on an RCBS chargemaster electronic scale to exactly the same weight. As I said the chrono didn't show any big deviations in velocity to account for the big drop. I suppose it could be shooter error - but like I said, almost every 1st shot was in the exact same place - dead center but about 3 MOA low. I doubt I'm that good to be able to pull a shot to the same spot everytime.
Anyone have a diagnosis? I just find it hard to believe a Stainless precision barrel from a reputable company could perform this poorly due to such slight changes in temps. Any help would be appreciated!
SO my issue is I'm getting what I consider excessive shifts in POI on every 1st shot in each 5 shot string. The 1st one I attributed to a "cold" barrel. But it wasn't really cold as I warmed up on some factory stuff (about 20 rounds) before shooting my load development handloads. So the barrel was still warm. I shot 10 five shot strings in all and eEVERY single 1st shot was almost exactly 3 MOA low and centered in the horizontal. String #2 did the same thing, even thought I waited max of maybe 5 min to shoot the 2nd string - so the barrel was still pretty hot to the touch. I sped the next string up to see if it re-occured and sure enough, 1st shot 3 MOA low and then the next 4 would group pretty nicely in the bull. So I sped up up even more, essentially waiting as long as it took me to pick up the previous 5 brass, load a new mag of 5 and sit down to shoot. Maybe 2-3 min. It didn't matter, still 1st shot about 3 MOA low, next 4 decent group. At this point the barrel was too hot to even touch when I began a new string, so the the whole idea of a "cold" barrel was RTFO.
I even noticed a distinct difference in POI if I waited more than about 45-60 secs between shots. If I waited just that amount, the next shot would diverge from the group pretty significantly. To test that out, in one string I shot the normal 1st shot that fell 3 MOA low, waited about a min and #2 fell about 1.5 MOA low, and then the next three were touching. So the bullets seemed to be climbing the ladder until the barrel was REALLY hot and then they settled down.
I don't recall it shooting this badly with the factory match stuff. I would usually get a no kidding cold barrel shot low, but then after that all the strings would be normal unless an excessive amount of time elapsed.
I figured it could be the handloads - but the chrono is showing good ES and SDs (SDs in the mid teens) - so I don't think I'm putting together shitty ammo. I'm using 77grn SMKs, properly prepped LC08 once fired brass, and two groups of powder (TAC and IMR 4895) to compare to each other. ALL loads were weighed on an RCBS chargemaster electronic scale to exactly the same weight. As I said the chrono didn't show any big deviations in velocity to account for the big drop. I suppose it could be shooter error - but like I said, almost every 1st shot was in the exact same place - dead center but about 3 MOA low. I doubt I'm that good to be able to pull a shot to the same spot everytime.
Anyone have a diagnosis? I just find it hard to believe a Stainless precision barrel from a reputable company could perform this poorly due to such slight changes in temps. Any help would be appreciated!
