berettaprofessor
Member
Based on a question raised in this previous thread, I pursued trying an Audette's ladder with Varget as suggested.
I loaded twenty rounds of Varget at 0.2 grain increments starting at 41.0 grains per Lyman and going to 44.8 grains (max load in Lyman was 45.7 and it is compressed at that load). The bullet is a Hornady Match 168 BTHP, shot from a Stag AR10, 18" barrel, and OAL was 2.800 as per Hodgdon 2019. The Stag is sighted to my previous "best" load, Benchmark 37.5 grains and I made one shot before the ladder with that load to make sure I was on target (Caldwell target photo). Very sunny day, temp around 87 degrees.
I "kind of" got a ladder with velocity, but my first lesson learned is why the standing advice is to shoot at 300 yards or more so the distance between hits is increased and you can see grouping nodes better. Aim point was the black dot and the round below it was the 41.0 grain starting load. Unfortunately, I was only able to shoot at 65 yards today, and since the longest range I could have done in the vicinity was 100 yards, I just took what I had. I kept track of the individual hits and their vertical height is, for the most part, consistent with the bullet velocity (see picture).
But, to my surprise, the velocity sometimes decreased with the next 0.2 grain increase (see chart). Does that happen often? Anyone know why? And yes, before you ask, I'm 99% sure I kept the rounds in the correct loading order. The Chronograph was a Chrony Alpha Master and I've always thought it was pretty accurate, although it didn't read two of the 20 projectiles today. Hodgdon lists the 42.0 load as 2520 fps and I chronyed it at 2543 today so that's reasonably close (although Hodgdon used a 24" barrel), and Lyman lists the 41.0 starting load at 2491, while I chronyed it at 2502. The highest load, 44.8 grains Varget, was starting to flatten the Primer a bit (see picture) so I'm happy to stop there, even though there could be another starting node around the top..
With my novice experience, I would estimate the best accuracy node at somewhere between 43.2 to 43.6, since these rounds varied by only 9 fps maximum. Anyone else agree? Because my next is to load up a bunch of 43.4 and see how consistent it is.
I loaded twenty rounds of Varget at 0.2 grain increments starting at 41.0 grains per Lyman and going to 44.8 grains (max load in Lyman was 45.7 and it is compressed at that load). The bullet is a Hornady Match 168 BTHP, shot from a Stag AR10, 18" barrel, and OAL was 2.800 as per Hodgdon 2019. The Stag is sighted to my previous "best" load, Benchmark 37.5 grains and I made one shot before the ladder with that load to make sure I was on target (Caldwell target photo). Very sunny day, temp around 87 degrees.
I "kind of" got a ladder with velocity, but my first lesson learned is why the standing advice is to shoot at 300 yards or more so the distance between hits is increased and you can see grouping nodes better. Aim point was the black dot and the round below it was the 41.0 grain starting load. Unfortunately, I was only able to shoot at 65 yards today, and since the longest range I could have done in the vicinity was 100 yards, I just took what I had. I kept track of the individual hits and their vertical height is, for the most part, consistent with the bullet velocity (see picture).
But, to my surprise, the velocity sometimes decreased with the next 0.2 grain increase (see chart). Does that happen often? Anyone know why? And yes, before you ask, I'm 99% sure I kept the rounds in the correct loading order. The Chronograph was a Chrony Alpha Master and I've always thought it was pretty accurate, although it didn't read two of the 20 projectiles today. Hodgdon lists the 42.0 load as 2520 fps and I chronyed it at 2543 today so that's reasonably close (although Hodgdon used a 24" barrel), and Lyman lists the 41.0 starting load at 2491, while I chronyed it at 2502. The highest load, 44.8 grains Varget, was starting to flatten the Primer a bit (see picture) so I'm happy to stop there, even though there could be another starting node around the top..
With my novice experience, I would estimate the best accuracy node at somewhere between 43.2 to 43.6, since these rounds varied by only 9 fps maximum. Anyone else agree? Because my next is to load up a bunch of 43.4 and see how consistent it is.
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