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I tested lesser charges with CFE before this last trip, so I knew that 31.0gr under the 123gr A-MAX and SST were fine in my Grendel. Hornady book max was with Hornady brass, CFE223, and another primer-printed in the 9th Edition. They maxed out at 2500fps with an 18" Alexander Arms test rifle pushing the 120-123gr pills with 31.2gr at 2.245" COL in a SAAMI Grendel chamber. Notice that I loaded waaaay long for COL at 2.272"-2.275". I did that intentionally as to avoid compression as much as possible. Too much compression can equal very erratic pressures, which is not a good thing on the edge.
If you have worked with CFE before and reached 30-31.0grs, start there with small increments. If not, start at 29.0gr and work up. I used .3gr increments this time. Based on what numbers you were getting before, your barrel might find faster speed with lower charges than Hornady's, which is why I recommend working up the powder if it is a new component for your recipes. Another forum member asked me for recommended start loads for his bolt action Grendel, and I still strongly suggested starting at 29.0gr and working up from there. He did, and found some excellent loads along the pressure ladder, grouping well below 2" at 200yds. The start at 29.0gr gave him plenty of room to establish a trend line from which to expect velocity increases, so that when something erratic showed up, it was clear.
That said, I think you will have no problem reaching 2580fps. The main thing is, will it be a spike to that velocity, or a nice step up from the previous load. If you are able to slowly step up to 2580fps with a consistent 12-25fps increase per .3gr of charge weight, you should be in pretty good territory. I like what you were doing with multiple chronographs to mitigate chrono screen/lighting issues, so if you can do that, you will have even more reliable data. Your extra 2" of barrel should yield a little more speed.
Another good point that one of our members pointed out was that he likes to pick the least amount of charge weight step figures from a pressure ladder for accuracy, which is another way of approaching OCW. If you look at my last string, 31.4gr and 31.7gr only had 12fps increase, and 32.0gr was only 21fps above 31.7gr. When I run my next batch of the exact same string of loads, I will look and see if that trend is in the same place, and then load maybe 31.7gr (2532fps) for OCW using batches of seating depths as my new approach to barrel time.
Before I do that, I'm going to research a little more into CFE's behavior in the Grendel, but it looks to be one of the most promising powders right now, but with some nuances that should not go unrecognized. Make sure that you don't have any RF interference if you're using a digital scale at your bench (cell phones need to be far away). Looking forward to your results.
If you have worked with CFE before and reached 30-31.0grs, start there with small increments. If not, start at 29.0gr and work up. I used .3gr increments this time. Based on what numbers you were getting before, your barrel might find faster speed with lower charges than Hornady's, which is why I recommend working up the powder if it is a new component for your recipes. Another forum member asked me for recommended start loads for his bolt action Grendel, and I still strongly suggested starting at 29.0gr and working up from there. He did, and found some excellent loads along the pressure ladder, grouping well below 2" at 200yds. The start at 29.0gr gave him plenty of room to establish a trend line from which to expect velocity increases, so that when something erratic showed up, it was clear.
That said, I think you will have no problem reaching 2580fps. The main thing is, will it be a spike to that velocity, or a nice step up from the previous load. If you are able to slowly step up to 2580fps with a consistent 12-25fps increase per .3gr of charge weight, you should be in pretty good territory. I like what you were doing with multiple chronographs to mitigate chrono screen/lighting issues, so if you can do that, you will have even more reliable data. Your extra 2" of barrel should yield a little more speed.
Another good point that one of our members pointed out was that he likes to pick the least amount of charge weight step figures from a pressure ladder for accuracy, which is another way of approaching OCW. If you look at my last string, 31.4gr and 31.7gr only had 12fps increase, and 32.0gr was only 21fps above 31.7gr. When I run my next batch of the exact same string of loads, I will look and see if that trend is in the same place, and then load maybe 31.7gr (2532fps) for OCW using batches of seating depths as my new approach to barrel time.
Before I do that, I'm going to research a little more into CFE's behavior in the Grendel, but it looks to be one of the most promising powders right now, but with some nuances that should not go unrecognized. Make sure that you don't have any RF interference if you're using a digital scale at your bench (cell phones need to be far away). Looking forward to your results.
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