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Post by Kyle on Sept 15, 2019 18:44:41 GMT -5
As smokeless muzzleloader shooters extend the ranges they shoot, often the topic of ballistic coefficient comes up. To understand what a bullet's ballistic coefficient is and how it is expressed, you must know how the bullet is constructed and if the bullet fits the ballistic model in question. Most of the software and gear related to the shooting industry has been based on the G1 and G7 Ballistic Models. The G1 model and definitely the G7 ballistic model do not represent the real world trajectory of High Performance Muzzleloading Projectiles like the AccuMax and Aeromax AT LONGER RANGES. Yes you can use the G1 model to get a fair representation for CLOSE TO MID RANGE SHOOTING SOLUTIONS. The G8 ballistic model more closely matches the actual shape of the AccuMax and Aeromax bullets I have designed. There will be a lot more to come on this topic in the future. One ballistic app I would recommend that calculates shooting solutions based on this model is "Bullet Flight M". I have this app on my iPhone and I like the features it has. Looks like the 325 Aeromax .402" at 3145 FPS is approximately .294 G8. As I get time I will be listing G8 ballistic coefficients on my website, in addition to the G1 ballistic coefficients already there. I have attached a couple of reads for those interested. www.thefirearmblog.com/blog/2016/05/13/ballistics-101-ballistic-coefficient/apps.apple.com/us/app/bullet-flight-m/id300903039www.jbmballistics.com/cgi-bin/jbmgf-5.1.cgi |
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Post by ultimatepredator on Sept 17, 2019 3:21:59 GMT -5
Thanks Kyle that is some very interesting and useful information ... helped make a little more sense what is going on with the apps
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Post by Richard on Sept 17, 2019 16:01:17 GMT -5
Good information Kyle! Look forward to further discussions.
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Post by nick50471 on Sept 17, 2019 18:04:44 GMT -5
I would like to see AB custom drag curves for our bullets.
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Post by hillbill on Sept 18, 2019 3:44:31 GMT -5
Very interesting stuff Kyle, I think you are right.
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Post by Kyle on Sept 20, 2020 21:11:45 GMT -5
Got to go to the range today to verify zero's and test some bullets. This deer season I'll likely be totin' the .45 with the Aeromax .452" 328 Hard Core, so that was the bullet tested for that gun today 200-1000 yards. Conditions were: 69 degrees, 61% humidity, 28.7 pressure, 1720 elevation. I was shooting 108.6 grains by weight of H4895 out of my Heavily Built Hankins .45 with a modified #17 Krieger barrel. Average muzzle velocity was 3121 fps. Average 100 yard velocity was 2920 fps. This translates to a Doppler Verified ballistic coefficient of .238 G8 based on the bullet weight and the conditions, this BC carried true all the way to 1000 yards, actual drops matched the chart very closely. To match the 1000 yard impacts on the G1 model, the G1 BC 200-1000 was best represented by .444 G1. The G8 model is best used in my opinion for the AccuMax and Aeromax instead of the G1 model especially when shooting longer ranges. Remember - good data in good data out, junk in junk out.
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Post by Richard on Sept 21, 2020 13:17:15 GMT -5
Just a note here. Last Tuesday I shot 3068 fps with the 325 AeroMax using 100 gr. Of H-4895. Temps in the upper 60's, elevation around 950'. So what that translates to is 6 fps more velocity for each grain more powder. Unless you need that particular node, you are not getting much more "bang for your bucks?". It seems that once you reach a certain velocity, you get little return for additional powder.
My barrel is a 1-18" twist at 30".
There is no criticism here, just giving facts.
The extra 3 grain weight of the 328 hardcore probably figures a tiny bit in this scenario.
Probably another factor I had not considered was the fact I use direct ignition and Kyle uses the HIS.
Anyway I just thought I would add to the discussion for what it's worth.
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