The Oregonian
Well-Known Member
New to reloading here…went out this weekend to work on load development after spending the last few weeks learning and loading. Puzzled by the results.
I have a factory A-bolt in 270 win. I am using Nosler once fired brass (from factory ammo), ABLR 150gr, H4350, and Fed 210M primers. I used the Nosler load data as a guide.
Nosler lists H4350 (which it said was most accurate powder tested) as follows:
52gr (max, most accurate load) – 2782 fps. 88% load density.
50gr 2657 fps, 84% load density
48gr 2532 fps, 81% load density
Based on this, I loaded 6 rds at each of the following…50gr, 50.5, 51, 51.5, 52gr. I used 3.372 as COAL, which is .015 shorter than mag length. Not sure where the lands start, but it is at least .020 farther out that mag length.
What I found is the following – primers started to flatten slightly at 51gr. I used OCW (i.e. I didn't do ladder test – wanted to keep it simple the first time ever trying to decipher the results of my loading). I fired one round at each powder charge, and the first three were without Magnetospeed, while the next three rounds were with the Magnetospeed. I used a different target for each powder charge, but I should have separated the Magnetospeed from those without it b/c of change in POI, so lesson learned.
I found that 50.5 to 51.5 seemed to be more consistent in grouping when comparing those three targets to each other, but my velocities were significantly higher than Nosler (50 to 100 fps at same powder charge). And 'more consistent' I use loosely - I wouldn't say I was thrilled with group size – 2 to 2.5 MOA or so for 6 shots. But since I didn't separate the magnetospeed rounds it is a little hard to say exactly (lesson learned) as I understand the POI can change by an MOA or more. The factory ammo I used gave me ~ .75 MOA. Two of those shots opened the day, and the last finished the day.
50gr – readings of 2799, 2771, and 2718 – vs Nosler's 2657
50.5 gr – readings of 2834, 2810, and 2776
51gr – 2829, 2780, and 2793
51.5gr – 2832, 2865, 2865
52gr – 2824, 2849, and 2845 (vs Nosler's 2782)
My velocities seem to vary quite a bit…and the flattened primers have me concerned. It seems to me that a few things could be happening:
1) My case capacities are down and therefore velocities are up. But I only neck sized the once fired's, and they measured fine of the Wilson headspace gage.
2) My powder charges weren't accurate – but I double checked them. I used a Lyman M5 I just got back from Scott Parker and checked them on a digital. There were all well within .1gr unless my scales were all wrong, and I checked them vs known weights (bullets) and they measured within .1gr.
3) The hot weather caused a spike – possible, but I thought Hodgdon were very temp stable, and the Nosler factory 130gr ammo didn't exhibit and primer flattening. I used these as foulers and to check zero prior to getting started.
4) This is not unusual and I should keep going with load development after backing down from flattened primers. I should focus on the 48gr to 51gr, and play with seating depth to bring group size down.
Any feedback on the results or where to focus next?
What puzzles me is why the velocities seem to be inconsistent and much higher than Nosler, flattened primers well below Nosler's max (and most accurate load).
Pics of individual targets and of a normalized target with each of the 18 shots captured relative to a common point of aim (CC shown for size reference).
I have a factory A-bolt in 270 win. I am using Nosler once fired brass (from factory ammo), ABLR 150gr, H4350, and Fed 210M primers. I used the Nosler load data as a guide.
Nosler lists H4350 (which it said was most accurate powder tested) as follows:
52gr (max, most accurate load) – 2782 fps. 88% load density.
50gr 2657 fps, 84% load density
48gr 2532 fps, 81% load density
Based on this, I loaded 6 rds at each of the following…50gr, 50.5, 51, 51.5, 52gr. I used 3.372 as COAL, which is .015 shorter than mag length. Not sure where the lands start, but it is at least .020 farther out that mag length.
What I found is the following – primers started to flatten slightly at 51gr. I used OCW (i.e. I didn't do ladder test – wanted to keep it simple the first time ever trying to decipher the results of my loading). I fired one round at each powder charge, and the first three were without Magnetospeed, while the next three rounds were with the Magnetospeed. I used a different target for each powder charge, but I should have separated the Magnetospeed from those without it b/c of change in POI, so lesson learned.
I found that 50.5 to 51.5 seemed to be more consistent in grouping when comparing those three targets to each other, but my velocities were significantly higher than Nosler (50 to 100 fps at same powder charge). And 'more consistent' I use loosely - I wouldn't say I was thrilled with group size – 2 to 2.5 MOA or so for 6 shots. But since I didn't separate the magnetospeed rounds it is a little hard to say exactly (lesson learned) as I understand the POI can change by an MOA or more. The factory ammo I used gave me ~ .75 MOA. Two of those shots opened the day, and the last finished the day.
50gr – readings of 2799, 2771, and 2718 – vs Nosler's 2657
50.5 gr – readings of 2834, 2810, and 2776
51gr – 2829, 2780, and 2793
51.5gr – 2832, 2865, 2865
52gr – 2824, 2849, and 2845 (vs Nosler's 2782)
My velocities seem to vary quite a bit…and the flattened primers have me concerned. It seems to me that a few things could be happening:
1) My case capacities are down and therefore velocities are up. But I only neck sized the once fired's, and they measured fine of the Wilson headspace gage.
2) My powder charges weren't accurate – but I double checked them. I used a Lyman M5 I just got back from Scott Parker and checked them on a digital. There were all well within .1gr unless my scales were all wrong, and I checked them vs known weights (bullets) and they measured within .1gr.
3) The hot weather caused a spike – possible, but I thought Hodgdon were very temp stable, and the Nosler factory 130gr ammo didn't exhibit and primer flattening. I used these as foulers and to check zero prior to getting started.
4) This is not unusual and I should keep going with load development after backing down from flattened primers. I should focus on the 48gr to 51gr, and play with seating depth to bring group size down.
Any feedback on the results or where to focus next?
What puzzles me is why the velocities seem to be inconsistent and much higher than Nosler, flattened primers well below Nosler's max (and most accurate load).
Pics of individual targets and of a normalized target with each of the 18 shots captured relative to a common point of aim (CC shown for size reference).
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