Took my R700 223 Wylde with Bartlein HV 28" 8T and .080" FB out this morning and did a quick 9 shot ladder at 300 yards. Get an idea of pressure/velocity and find the upper node.
80.5g Bergers, approx .020 off, COAL 2.485", N540, Rem 7.5 and 2x fired Lapua brass. Shoulders bumped .002" and neck tension also .002"
It left me with more questions than answers, and didn't really show anything definitive in my opinion. The overall group wasn't bad, about 1 MOA for all 9 shots, but no real correlation to velocity/impacts either. Also, the jump in velocity of 70fps from 24.1 (2876) to 24.3 (2946) had me thinking I was around max, but there were no obvious signs of pressure anywhere. The jump from 24.3 to 24.5 was pretty normal again at 35fps. Not sure if I should creep up in .1g increments to find max with the velocity I'm already at, but I have a feeling there might be a node at that 24.5 (2980) area.
I also had something super odd happen and I can't explain it or figure it out. While trying to get my seating depths figured out, I had 3 extra rounds all loaded at 23.5 Only difference was 1 was really short at 2.4" and the other 2 were pretty dang close to where they were suppose to be at around 2.480". I figured I'd use the shortest one for a cold bore and see where it impacted at 300 and get a good zero to go off. Velocity read 2811fps. Ok no problems there. So I shoot the 9 shot ladder and the 23.5 charge showed 2829fps. OK still doing fine. Finished up the ladder and still had those extra 2 cartridges loaded at I decided to use them up on the 500 yard gong and get some more numbers from the garmin. I was shocked when the 1st read 3063fps. No hard bolt lift, cases look fine, primer looked fine, so I shot the last one and it was 3053fps. Again, no obvious signs of pressure. But my main concern and question here is how on earth was there a 225fps discrepancy in velocity with those 2 shots at 23.5 from the previous 2 at 23.5? I individually weighed each charge on a balance beam and I'm certain the Garmin is ok.
I was shooting for 2950fps with no pressure, as that seems about right for an 80g bullet and 28" barrel. I'm thinking 3050fps is definitely over pressure, even though I'm not seeing the tall tale signs. And I'm not even totally sure what to think of those 2 rounds that hit 3050fps at that low charge weight anyway.
Anyway I'd love to hear your guys thoughts and where you would go from here? Still better than a good day at work, but still a little frustrated also...
Target dot is 2"
80.5g Bergers, approx .020 off, COAL 2.485", N540, Rem 7.5 and 2x fired Lapua brass. Shoulders bumped .002" and neck tension also .002"
It left me with more questions than answers, and didn't really show anything definitive in my opinion. The overall group wasn't bad, about 1 MOA for all 9 shots, but no real correlation to velocity/impacts either. Also, the jump in velocity of 70fps from 24.1 (2876) to 24.3 (2946) had me thinking I was around max, but there were no obvious signs of pressure anywhere. The jump from 24.3 to 24.5 was pretty normal again at 35fps. Not sure if I should creep up in .1g increments to find max with the velocity I'm already at, but I have a feeling there might be a node at that 24.5 (2980) area.
I also had something super odd happen and I can't explain it or figure it out. While trying to get my seating depths figured out, I had 3 extra rounds all loaded at 23.5 Only difference was 1 was really short at 2.4" and the other 2 were pretty dang close to where they were suppose to be at around 2.480". I figured I'd use the shortest one for a cold bore and see where it impacted at 300 and get a good zero to go off. Velocity read 2811fps. Ok no problems there. So I shoot the 9 shot ladder and the 23.5 charge showed 2829fps. OK still doing fine. Finished up the ladder and still had those extra 2 cartridges loaded at I decided to use them up on the 500 yard gong and get some more numbers from the garmin. I was shocked when the 1st read 3063fps. No hard bolt lift, cases look fine, primer looked fine, so I shot the last one and it was 3053fps. Again, no obvious signs of pressure. But my main concern and question here is how on earth was there a 225fps discrepancy in velocity with those 2 shots at 23.5 from the previous 2 at 23.5? I individually weighed each charge on a balance beam and I'm certain the Garmin is ok.
I was shooting for 2950fps with no pressure, as that seems about right for an 80g bullet and 28" barrel. I'm thinking 3050fps is definitely over pressure, even though I'm not seeing the tall tale signs. And I'm not even totally sure what to think of those 2 rounds that hit 3050fps at that low charge weight anyway.
Anyway I'd love to hear your guys thoughts and where you would go from here? Still better than a good day at work, but still a little frustrated also...
Target dot is 2"
