Hey all, new reloader here. I have a question regarding pressure signs, specifically when it comes to ejector marks/swipe. A little info to start...
The rifle:
Bergara Wilderness Ridge in 7mm Rem Mag, 24" barrel, 1:9.5 twist
The range:
Indoors, 100 yds., bi-pod and rear bag
The load:
175 gr. Berger Elite Hunter
VT-N560 powder, CCI 250 primers, New Peterson brass, seating 0.20" off the lands
Using the Berger reloading manual, the starting load for this particular powder and bullet is 60.5 gr., with a max load of 63.5 gr.
I loaded 3-shot strings starting at 61 gr. up to 62.2 gr. in 0.4 gr. increments and 62.4 gr. to 63.0 gr. in 0.2 gr. increments. I started to see what I considered a "node" at 62.8 gr. and 63.0 gr., with the group sizes at 0.38" and 0.33".
However, I started to notice the slightest ejector mark (just a little kiss) and slight swipe on the case head from operating the bolt for both of these loads. I do not notice this until I get to that 62.8 gr. mark. Again, it's very slight, but I prefer to stay away from too much pressure for obvious safety reasons...especially when I shoot outdoors in potentially hotter weather, etc. There are no issues with the primers. No flattening/cratering, or anything of that nature with any of these loads.
I've read about "false" pressure signs, especially with new brass, which I am currently using. That said, this information comes from the internet, and considering I'd prefer to stay away from pressure signs altogether, what are people's thoughts on this? I almost hate to back off on powder because it's really starting to group well. Maybe I can go back to that range where I was doing 0.4 gr. increments and do 0.2 or even 0.1 gr. increments and see what happens?
Of note, using this bullet/powder combination, the Berger manual spans a total of 3 gr. from starting to max load (60.5 gr. to 63.5 gr.). Looking at the Hornady manual, for a 175 gr. projectile and using this same power, the total range between starting and max load spans 8 gr. (52.6 gr. to 60.5 gr.). Also, the test rifle used in the Hornady manual (Rem 700, 24" barrel, 1:9 twist) more closely resembles my rifle than that in the Berger manual (26" barrel).
If it helps, here are the results of firing these different powder charges:
61.0 gr. (0.43" group)
61.4 gr. (0.76" group)
61.8 gr. (1.01" group)
62.2 gr. (0.82" group)
62.4 gr. (0.44" group)
62.6 gr. (0.94" group)
62.8 gr. (0.38" group)
63.0 gr. (0.33" group)
I guess my question is...where would you go from here? Should I be concerned with a soft kiss from the ejector? Is there really such a thing as "false" pressure signs with new brass? Is Peterson brass considered "soft" compared to other brands where something like this might happen? It might be hard to provide answers since I haven't put a chrono on it yet and have no velocity numbers, and maybe this isn't a big enough sample size. I was basically looking for raw accuracy to this point. Maybe this is all really stupid to ask about and I'll get a bunch of "welcome to HT" comments. Regardless, curious to hear thoughts or advice you have! Thanks!!
The rifle:
Bergara Wilderness Ridge in 7mm Rem Mag, 24" barrel, 1:9.5 twist
The range:
Indoors, 100 yds., bi-pod and rear bag
The load:
175 gr. Berger Elite Hunter
VT-N560 powder, CCI 250 primers, New Peterson brass, seating 0.20" off the lands
Using the Berger reloading manual, the starting load for this particular powder and bullet is 60.5 gr., with a max load of 63.5 gr.
I loaded 3-shot strings starting at 61 gr. up to 62.2 gr. in 0.4 gr. increments and 62.4 gr. to 63.0 gr. in 0.2 gr. increments. I started to see what I considered a "node" at 62.8 gr. and 63.0 gr., with the group sizes at 0.38" and 0.33".
However, I started to notice the slightest ejector mark (just a little kiss) and slight swipe on the case head from operating the bolt for both of these loads. I do not notice this until I get to that 62.8 gr. mark. Again, it's very slight, but I prefer to stay away from too much pressure for obvious safety reasons...especially when I shoot outdoors in potentially hotter weather, etc. There are no issues with the primers. No flattening/cratering, or anything of that nature with any of these loads.
I've read about "false" pressure signs, especially with new brass, which I am currently using. That said, this information comes from the internet, and considering I'd prefer to stay away from pressure signs altogether, what are people's thoughts on this? I almost hate to back off on powder because it's really starting to group well. Maybe I can go back to that range where I was doing 0.4 gr. increments and do 0.2 or even 0.1 gr. increments and see what happens?
Of note, using this bullet/powder combination, the Berger manual spans a total of 3 gr. from starting to max load (60.5 gr. to 63.5 gr.). Looking at the Hornady manual, for a 175 gr. projectile and using this same power, the total range between starting and max load spans 8 gr. (52.6 gr. to 60.5 gr.). Also, the test rifle used in the Hornady manual (Rem 700, 24" barrel, 1:9 twist) more closely resembles my rifle than that in the Berger manual (26" barrel).
If it helps, here are the results of firing these different powder charges:
61.0 gr. (0.43" group)
61.4 gr. (0.76" group)
61.8 gr. (1.01" group)
62.2 gr. (0.82" group)
62.4 gr. (0.44" group)
62.6 gr. (0.94" group)
62.8 gr. (0.38" group)
63.0 gr. (0.33" group)
I guess my question is...where would you go from here? Should I be concerned with a soft kiss from the ejector? Is there really such a thing as "false" pressure signs with new brass? Is Peterson brass considered "soft" compared to other brands where something like this might happen? It might be hard to provide answers since I haven't put a chrono on it yet and have no velocity numbers, and maybe this isn't a big enough sample size. I was basically looking for raw accuracy to this point. Maybe this is all really stupid to ask about and I'll get a bunch of "welcome to HT" comments. Regardless, curious to hear thoughts or advice you have! Thanks!!