Longrangers
Well-Known Member
So I get from this is tune your equipment for your application and know where your limits are for your capabilities as well equipment for the desired application.
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Hammer ballistic coefficient tests...
- Thread starter entoptics
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entoptics
Well-Known Member
- Joined
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I did intend to show it as a ratio, but very much appreciate your effort to also present it as the relative difference. Either method may be more or less helpful depending on how one prefers to digest the data. Apologies that my language wasn't clear.
The N for the Hammer bullets was between 5 and 9 (first load testing, done only in the last few weeks).
For most of the others, N is from 10-80. I have indeed noticed significant variation in measurements from bullet to bullet, and from outing to outing, but it's usually on the order of no more than ± 2% relative (see chart below for examples). I'd consider this "within error" for the LabRadar/Kestrel setup.
I've never intentionally tried to measure a range of velocities, but have some data for the same bullet in say a 30-06 and a 300 WM, and haven't noticed a huge difference. That said, I've not "crunched the numbers". I intend to try the remaining 284 Hammers/SBDII in my 7 Rem Mag, so I'll collect some data there and publish it here eventually.
Weather was 74.9° to 61.5°, station pressure from 27.514 - 27.523 inHg, and humidity was 30.2% - 42.85%. Readings were taken every 15 minutes or so, and the nearest time to the shot was used for the B.C. calculator input.
In my experience, the calculated B.C. doesn't change much in different weather conditions. After all, that's it's entire purpose. Here's a chart of T vs BC from rifles with enough data over a long period of time to show variation (there isn't much if any).
The title was chosen because that is the new data here for me, and the unusual results for the Hammer bullets are noteworthy. I only showed the other bullets because the Hammer numbers were so startling. I wanted to ensure that readers could see that other bullets came in reasonably close to their manufacturers stated values, to help validate the testing of the Hammers.
Nice work, and thanks for posting it. The info provided is definitely interesting to say the least, and not surprising to me.
Wow!!!
Hugnot
Well-Known Member
Good stuff. Fits better than 90% are encouraging.
As I mentioned, I will stick to H 4DOF calculation & self-verification. Enough bullets in their list for my purposes. If I can get a 90% or better fit using my low budget Magneto speed at 300 yards the indications are that it will be close enough at 500 plus for easy tuning.
As I mentioned, I will stick to H 4DOF calculation & self-verification. Enough bullets in their list for my purposes. If I can get a 90% or better fit using my low budget Magneto speed at 300 yards the indications are that it will be close enough at 500 plus for easy tuning.
The exception I take from this work is the Hammer BC is not calculated from an instrument such as a LabRadar but from their OWN field shot drops. I have taken any BC provided from shot drops as a suggestion more than an absolute.
As you mentioned, every rifle will be different as well as the altitude tested. It is up to EVERY shooter verify their own load and not rely upon a posted BC. I don't disagree that a bullet manufacturer should have a LabRadar for basic BC calculations but others like Hammer calculate from shot drops.
Even Cutting Edge who started in 2001, uses shot drops but are now switching over to Oehler so this is not an uncommon tactic to use for a bullet. So CE started in 2001, 14 years before Hammer are slowly converting over to newer technology.
Cutting Edge Bullets Website:
"At this point the Ballistic Coefficients of our bullets are not exact but are not exaggerated. We arrived at the stated BC's by using muzzle velocity and actual bullet drops at various ranges and calculated them using Oehler's Ballistic Explorer 6.2.0 software. We do realize this is not precise but anyone that has shot long distances will see the difference in drop when compared to the bullets you are currently shooting. As we move forward we plan to get more precise BC's by using an Oehler 43 or Oehler 83 chronograph with acoustic targets set at yardages out to 800 yards. The yardages will be certified and the ballistic coefficients will be very accurate. Eventually, to get even more accurate, we will have data obtained by using Doppler Radar and post it as well."
I appreciate the work but I see it comparing large long standing bullet manufacturers that have had greater resources for longer period of time to a bullet company that has been really producing bullets 6 years or so which is apples to oranges at best. Sure there are improvements that can be made and I hope some day to see technology to reflect that.
As you mentioned, every rifle will be different as well as the altitude tested. It is up to EVERY shooter verify their own load and not rely upon a posted BC. I don't disagree that a bullet manufacturer should have a LabRadar for basic BC calculations but others like Hammer calculate from shot drops.
Even Cutting Edge who started in 2001, uses shot drops but are now switching over to Oehler so this is not an uncommon tactic to use for a bullet. So CE started in 2001, 14 years before Hammer are slowly converting over to newer technology.
Cutting Edge Bullets Website:
"At this point the Ballistic Coefficients of our bullets are not exact but are not exaggerated. We arrived at the stated BC's by using muzzle velocity and actual bullet drops at various ranges and calculated them using Oehler's Ballistic Explorer 6.2.0 software. We do realize this is not precise but anyone that has shot long distances will see the difference in drop when compared to the bullets you are currently shooting. As we move forward we plan to get more precise BC's by using an Oehler 43 or Oehler 83 chronograph with acoustic targets set at yardages out to 800 yards. The yardages will be certified and the ballistic coefficients will be very accurate. Eventually, to get even more accurate, we will have data obtained by using Doppler Radar and post it as well."
I appreciate the work but I see it comparing large long standing bullet manufacturers that have had greater resources for longer period of time to a bullet company that has been really producing bullets 6 years or so which is apples to oranges at best. Sure there are improvements that can be made and I hope some day to see technology to reflect that.
Hard rock
Well-Known Member
Mean while I'll keep shooting Hammer bullets just got three new boxes yesterday.
As will I. Copper bullets will most likely never achieve the BC numbers of top target bullets or even top LR hunting bullets. In the copper world Hammers have been the most consistant and easiest to tune. I got tired of opening boxs of LRX's and seeing tips that are not seated all the way or off center.
Hammers have proven to be the exact same in every box. I verified my numbers to be accurate in my rifle. When I drop the hammer on a Hammer things die.
I'll add to this just a little. Saturday morning I went down to our property that was just clear cut and hung a six inch plate from a clearing at 650 yds where I set my shooting table where I'd hoped over the next couple of weeks on a cool morning I'd go shoot a few rounds. My oldest daughter called late yesterday wanting to go shoot pistols whenever I had a chance so I suggested we go today in between rain showers. Long story short, I had four rounds for my 270 Weatherby and five from my 30-378 from last hunting season that needed to be shot to start the upcoming season. Both rifles I'd cleaned to bare metal as soon as season was over last year and have been in the safe since. Dope for both were 11 and 11.2 MOA at 650 and with no fouler rounds, put all nine shot on the plate. These were 117HH's in the 270 and 181 HH's in the 30-378.
Hugnot
Well-Known Member
The Sg's look real good for the bullets shown.
I ran these using a slower velocity than the big .264 WM, like would be expected from a 6.5 Creedmoor having an 8 twist. Sg's should be slightly higher with the big speedy .264 WM.
I also checked my numbers against JBM using the 147 Hornady ELDM, not have an actual bullet to measure I used JBM data.
Any info how JBM does BC calcs using velocity differences? The bullets tested should be flying real good with minimum wobbling. The Hornady 4DOF uses drag coefficients vs. comparisons to some standard bullet. BC's change during bullet flight. I would like to see the JBM method.
I ran these using a slower velocity than the big .264 WM, like would be expected from a 6.5 Creedmoor having an 8 twist. Sg's should be slightly higher with the big speedy .264 WM.
I also checked my numbers against JBM using the 147 Hornady ELDM, not have an actual bullet to measure I used JBM data.
Any info how JBM does BC calcs using velocity differences? The bullets tested should be flying real good with minimum wobbling. The Hornady 4DOF uses drag coefficients vs. comparisons to some standard bullet. BC's change during bullet flight. I would like to see the JBM method.
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TheSouthpaw
Well-Known Member
Thanks for the data and report. Our findings have been similar. In 5 different rifles with hammers the BC true'd out ~.3 below the website advertised estimate. They lined up about perfect with the Applied Ballistics BC values (.277 117HH and .264 124HH).
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Andrew Massi
Well-Known Member
Cutting edge currently has 2 7mm lazers (160&185) with g1 +.600. G7+.300
jasent
Well-Known Member
Badlands even better that those
Yes they do. They also use a denser alloy than other copper bullets. One reason they are so expensive. Word is they use a copper bronze alloy. They have a high sectional density. I'm sure they don't want to reveal that publicly so other company's don't catch on. I also don't feel their drive band design is very practical to most reloaders. Just my 2 cents.
From some other testing I've seen. They are slightly inflated as well. If I gotta spend $60+ for a box of bullets. I want something that is practical to load and accurate. Cutting Edge has even said they don't have the equipment at the moment to produce the numbers as accurate as say Berger and Hornady.
If you want accurate BC numbers without testing real world drops. Then subscribe to Litz's publication. They are dead accurate. My real world test I've done are with in 6% of Litz's information. That percentage will very rifle to rifle. I never said I had a problem. Just info I got from real world drops. At a minimum BC should very verified at 800 yards and beyond to get them perfect.
