04-20-2024, 12:45 PM
I got out this week with a few loads of the 105 Scenars and the Berger 109s over Varget. Unfortunately I have no idea how to post a picture in a reply on this site. Long story short, I learned a few things:
1. The Forstner "Ultra" seating die does an excellent job seating VLDs, (probably any secant ogive bullet, in my case Berger 109s), but totally sucks at seating any tangent ogive bullet, (in my case the Lapua 105 scenars). The design of the die is great, the seating stem is just about the diameter of a fired case neck and it travels in a tube that slides concentric with the neck with the case in a tight chamber so everything is aligned very well. The problem is that this means it contacts a tangent ogive projectile way out near the nose so the datum point seating depth varies a lot. .024 in my 20 round sample of lapua 105s. I Called Forstner and they offered to make me a custom seating stem if I sent them some fire formed and sized cases and a handful of the scenars. But when I took the die apart and miked it, that stem would have to have a 1/4" long end that was paper thin to get to the datum point, (.240) on a tangent ogive bullet). Not practical IMHO. So I sent the die back to Midsouth, (hoping for a refund), and ordered the Wilson seater with both stems.
2. On Wednesday I shot a few of both bullets at 100 yds loaded light, and seated comfortably short of the lands, to get some chrony data for a baseline and some fired brass to set up the dies and measure case capacity. 40 deg F, wind 20 to 25 mph at 12;00 o'clock. The day wasn't great. The Scenars couldn't break 1 Moa, (duh, with the OAL all over the place form the Forstner seating die), but at 25.5 grains of Varget the Berger 109s produced a 3/4" three shot group that I could walk into the center of the target with the last two shots, Enough to make me think I could move out to 200 yards where things get meaningful. No pressure signs and velocities well below max.
3. this morning I went back out with an abbreviated pressure ladder for the Berger 109s loaded longer, (2.30) and five Scenars loaded at 26 grains of Varget .1 into the lands, (2.260). The scenars made a 1-1/2 group at 200 nothing to write home about. The Berger ladder was mediocre until I got up over 26 grains when they started to tighten up. At 26.4 I printed four shots into 9/16" , with one flyer opening the group to 1-1/2". Av Vel 2516, SD 8.1. This shows promise. This barrel has less than 30 rounds on it and I really don't expect it to settle in until at least 75 rounds. The white oak barrel on my .223 didn't settle down until 100 rounds.
1. The Forstner "Ultra" seating die does an excellent job seating VLDs, (probably any secant ogive bullet, in my case Berger 109s), but totally sucks at seating any tangent ogive bullet, (in my case the Lapua 105 scenars). The design of the die is great, the seating stem is just about the diameter of a fired case neck and it travels in a tube that slides concentric with the neck with the case in a tight chamber so everything is aligned very well. The problem is that this means it contacts a tangent ogive projectile way out near the nose so the datum point seating depth varies a lot. .024 in my 20 round sample of lapua 105s. I Called Forstner and they offered to make me a custom seating stem if I sent them some fire formed and sized cases and a handful of the scenars. But when I took the die apart and miked it, that stem would have to have a 1/4" long end that was paper thin to get to the datum point, (.240) on a tangent ogive bullet). Not practical IMHO. So I sent the die back to Midsouth, (hoping for a refund), and ordered the Wilson seater with both stems.
2. On Wednesday I shot a few of both bullets at 100 yds loaded light, and seated comfortably short of the lands, to get some chrony data for a baseline and some fired brass to set up the dies and measure case capacity. 40 deg F, wind 20 to 25 mph at 12;00 o'clock. The day wasn't great. The Scenars couldn't break 1 Moa, (duh, with the OAL all over the place form the Forstner seating die), but at 25.5 grains of Varget the Berger 109s produced a 3/4" three shot group that I could walk into the center of the target with the last two shots, Enough to make me think I could move out to 200 yards where things get meaningful. No pressure signs and velocities well below max.
3. this morning I went back out with an abbreviated pressure ladder for the Berger 109s loaded longer, (2.30) and five Scenars loaded at 26 grains of Varget .1 into the lands, (2.260). The scenars made a 1-1/2 group at 200 nothing to write home about. The Berger ladder was mediocre until I got up over 26 grains when they started to tighten up. At 26.4 I printed four shots into 9/16" , with one flyer opening the group to 1-1/2". Av Vel 2516, SD 8.1. This shows promise. This barrel has less than 30 rounds on it and I really don't expect it to settle in until at least 75 rounds. The white oak barrel on my .223 didn't settle down until 100 rounds.