Does anyone use one of the purchased CDMs with pointed bullets or had to alter them for different lots of bullets? How does it work? What did you do to modify the results? I was looking at getting the AB app for my iPhone and buying the 140 Berger CDM. When I shot Bergers in the past I pointed my 140s, which increased the g7 about 3% from .311 to .320. I was also looking at getting the CDM for the 147 ELDM. Lately I've been having awful luck with the solution past 500 from the Hornady DoF app. I've been having to correct the bullet factor to 1.10 and it is still off by a bit. The range I have access to for paper is about 300, or 470 for steel.
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Applied Ballistic App Custom Drag Model and pointed bullets or different lots
- Thread starter TRG65
- Start date
The only things you can change in CDC is MV and optic height.
300 and 470 are likely not going to be enough to get you a good curve to 1k. The CDC may match up on its own. But if it doesn’t, 470 likely won’t get it there for you.
300 and 470 are likely not going to be enough to get you a good curve to 1k. The CDC may match up on its own. But if it doesn’t, 470 likely won’t get it there for you.
Once you change the bullet you’d need to create a new CDM for it.
Getting a decent curve with the 147’s isn’t difficult with the 4dof, if you’re having to correct the drag factor all the way to 1.1 your inputs are in question in my opinion.
Unless you’re able to get actual location station pressure to input your just guessing with the phone apps.
Having accurate air conditions information is a lot more precise than some weather station somewhere 20 miles away probably providing corrected air pressure.
Getting a decent curve with the 147’s isn’t difficult with the 4dof, if you’re having to correct the drag factor all the way to 1.1 your inputs are in question in my opinion.
Unless you’re able to get actual location station pressure to input your just guessing with the phone apps.
Having accurate air conditions information is a lot more precise than some weather station somewhere 20 miles away probably providing corrected air pressure.
The creating a new CDM and only being able to modify mv is what I was afraid of. I'll just stick with modifying the G7. With the cartridge/load I shoot most, the bullet doesn't drop below mach 1.5 until about 1000-1050 yd. Beyond that is only a handful or less of shots per match.
With the last lot of 147 eldm bullets I was at a correction of 1.05, and then for this lot it jumped to 1.1. I've had other problems with this lot as I've had to rework all my loads due to a .015 difference in ogive/bearing surface, causing significant pressure and velocity changes. Hence the reason I was looking at going back to Bergers. I shot them for years and while the lengths vary, if I seated to the same ogive/cartridge length I didn't have to worry about a new box. I went to the Hornady for cost savings, but across the multiple rifles I use them in, I've lost over 10% of the bullets just to load rework/tuning, not to mention the time and gas involved (range is 2 hours each way).
I'm using the station pressure from my kestrel and the velocity from my magnetospeed. Many of the places I've shot over the years have no cell service, so I have two methods of getting station pressure and temp, my kestrel and my pathfinder watch (which works for pressure but for temp it has to be off wrist for a while).
With the last lot of 147 eldm bullets I was at a correction of 1.05, and then for this lot it jumped to 1.1. I've had other problems with this lot as I've had to rework all my loads due to a .015 difference in ogive/bearing surface, causing significant pressure and velocity changes. Hence the reason I was looking at going back to Bergers. I shot them for years and while the lengths vary, if I seated to the same ogive/cartridge length I didn't have to worry about a new box. I went to the Hornady for cost savings, but across the multiple rifles I use them in, I've lost over 10% of the bullets just to load rework/tuning, not to mention the time and gas involved (range is 2 hours each way).
I'm using the station pressure from my kestrel and the velocity from my magnetospeed. Many of the places I've shot over the years have no cell service, so I have two methods of getting station pressure and temp, my kestrel and my pathfinder watch (which works for pressure but for temp it has to be off wrist for a while).
Well
I’ve certainly seen changes in lot’s from Hornandy.
That’s why when buying bullets for important situations it’s not from Hornandy.
I’ve certainly seen changes in lot’s from Hornandy.
That’s why when buying bullets for important situations it’s not from Hornandy.
I had this question only a few months ago and could not find the answer. I ended up calling AB. The gentleman said to adjust the MV. Which suprised me that altering the shape of the bullet does not do very much. I would be very interested to hear if anyone has used one of the personal drag models with and without pointed bullets (all else being the same) and what kind of differences it makes.
I don't shoot nearly enough to give any credible results
I don't shoot nearly enough to give any credible results
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