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Berger Bullet BC

I am posting this here since I want to reach as many of you as possible and I am not sure you look at all the other groups.

To All,

I have read several posts commenting on the BC of Berger Bullets. It is important that I relay to all of you how we calculate the BCs that we publish. It is important that I tell you up front that minds that are far more intelligent than mine have created our published BC. I will relay our methods and say up front that I cannot defend them beyond saying that I trust the individuals involved to be extremely knowledgeable in this area. Having said that we have received tremendous feedback that our methods are sound.

Our published BC is the result of running dimensional data through a program created by Bill Davis. Bill's program assumes a zero yaw environment,more on that later) and is figured using an Army Standard Metro environment. The Army Standard Metro environment is zero elevation, 59 degrees Fahrenheit, 78% humidity and 29.53 inches of mercury barometric pressure. These details are not important except for the fact that most manufacturers in the industry use them.

You may have noticed that our published BCs changed recently. This is a result of the fact that we have much better measuring equipment available to us today. The original BCs were figured based on measurements acquired using ogive gages and other rough estimates. Today we have high tech measuring equipment that is capable of finding any dimension down to the .00005,yes, four zeros). When we remeasured and Walt refigured the BC we found differences. Our website and recent brochure list the correct BCs based on this new method.

This brings me back to my statement about using a zero yaw environment. Every rifle produces an amount of yaw,those that don't are called hummers and are precious and rare). Also, each rifle has characteristics that are specific to that rifle. A shot BC is nothing more than the BC achieved when shot out of that particular rifle. It is no more accurate to your rifle than a calculated BC. We feel that it is best to provide a standard. Since dimensionally calculated BCs are always the same in relation to each other we feel this was the best way for us to produce a BC that we publish.

Now for the important question: What does this mean to me as a shooter? If you plug our published BC into a trajectory program you will produce a drop chart that is going to be very close to what you experience on the range. If you find that the realized drop at the range is different than the drop chart predicts simply rerun the trajectory chart using slightly adjusted BCs to produce the exact drop you experienced in your rifle. This will give you the exact BC for that bullet coming out of your rifle.

Example,using assumptions): A BC of .472 in your trajectory program tells you that at 1000 yards you will drop 33 MOA at 1000 yards. Establish a true zero by shooting at 100 yards first,assuming you use 100 yards as the zero in your trajectory program) then crank 33 MOA drop into your scope. Fire a shot at 1000 yards. You should impact pretty close to your horizontal cross hair. Let's assume your shot was low by 5 inches. Shoot a couple more shots,or several) to verify your findings. Assuming all shots were consistently about 5 inches below the horizontal cross hair you can go back to your trajectory program and change the BC,in this case lower it) to .469,example) and this should give you 33.5 MOA drop,assumption) on the drop chart that the program produces. This means that out of your rifle, this bullet has a BC of .469. You now have a drop chart that is hyper accurate allowing you to make MOA adjustments from muzzle to 1500 yards,or more if you want) based on this drop chart data.

Our published BC is a standard that is meant to be as accurate as possible for a large group of people shooting everything from high velocity to low velocity, fast twist to slow twist. Remember, our BC is figured assuming a zero yaw environment. If you go through the process explained above and find your drop to be considerably more than the drop chart lists using our published BC you have a situation where your rifle is producing a significant amount of yaw when the bullet exits the muzzle. You should work on,tweak) your combination of components as you are giving away quite a bit by having such an unstable situation.

There are some of you that are convinced that our published BCs are high for the purpose of selling bullets. If you believe this you do not know anything about Walt Berger, Bill Davis or myself. All of us are truly dedicated to providing you with the best shooting experience you can achieve. If you are convinced other bullets are better,or their BCs are more accurate since we have "ulterior" motives) then go ahead and shoot the other brands. Everything I have stated in this post is absolutely true and if you think our methods of producing a BC are motivated by anything other than your complete enjoyment of the shooting experience then you should think about why you feel this way. What I mean is, do you actually believe we are trying to scr*w you? If you do I am sorry that we have wronged you in some way and I hope we can find a way to make it right.

Regards,
Eric Stecker
Berger Bullets
 
Eric,

Thank you for your informative post. I for one just use a published BC as a guide in selecting a particular bullet for evaluation. Too many people get caught up in numbers, BC being one of them, velocity another. I have always felt that the proof is on the target not in some ballistic program.
In my 6BR the Berger 105 grain VLD has proven itself time and time again in match conditions for my particular rifle/barrel/load combination. Small groups in the ten ring mean a lot more than a published BC. BC's don't win matches. I don't care if a bullet has a supposed super high BC, if it dosen't group that number becomes a moot point. I'm no amateur ballistician caught up in numbers in a computer program, and I think you'll find that most other shooters are of the same mind set.
I've shot Berger bullets in my 6BR's now for years, if they wouldn't shoot I wouldn't be using them. Performance, availability, and fair price have been my experience with Bergers. You won't get any complaints from me!

Danny Reever
 
Eric:
There is one major factor that is being ignored in this discussion.
That being the variance in accuracy of the sighting instrument used in the field,ie: scope, irons or what ever) to corrolate,sp) TRUE elevation. Thread pitch of either irons or scope are only as good as, or true as they can be. There are many reasons for actual errors.,true angular movement is only exact at a specific radius in relation to thread pitch)
Sight radius of irons and metric threads used in a lot of scopes these days and the corresponding detent increments all will result in SOME amount of error over distance, thereby, over the range from 100 to 1000 will have a built in amount of error.
I cannot speak to scope error as well as to irons, where an exact sight radius yeilds an absolute true increment, but I know from comparing notes from what I know with irons, that scopes other than old Unertls with external english threads, there are errors in EVERY other scope I've ever used, thereby creating those errors.
Finding an "error" of 1/2 minute @1000 is well within the built in error caused by the instrument.

Alan,
 
Eric, keep doing what you are doing because you are doing it very well.

I have found no better bullet for my AR-15 service rifle than your 80 grain VLD. It is clearly superior in my weapon to anything from Nosler, Hornady, and Sierra.

I gotta try your 6.5 mm offerings in my 260 Rem M70. I suspect that new 130 VLD is going to be the cat's meow at 600.
 
Eric -- thanks for the post. Should serve as a good reference.

Alan, good point about displaced blame when evaluating a BC...I don't get too hung up on BC, but when I see different bullets hitting obviously higher at 1K than another when launched at the same velocity back-to-back, it tells me something :D

Jason
 
Jason:
I agree with you.
My criteria is groups at distance only.
If I told of my chrono numbers prior to Sac, you would
raise an eyebrow.

Alan
 

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