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Re: Does A High BC Always Equal Better Accuracy?
Depends on many variables. At the 100 yard line BC means little, at longer ranges it becomes important but it has more to do with trajectory.
Depends on many variables. At the 100 yard line BC means little, at longer ranges it becomes important but it has more to do with trajectory.
Re: Does A High BC Always Equal Better Accuracy?
BC in itself has nothing to do with accuracy. There are more accurate bullets that many use for short range. The reason its associated with accuracy is that when dealing with long range, it bucks wind better and shoots flatter.. which compensates for the shooters inaccuracies.
BC in itself has nothing to do with accuracy. There are more accurate bullets that many use for short range. The reason its associated with accuracy is that when dealing with long range, it bucks wind better and shoots flatter.. which compensates for the shooters inaccuracies.
Re: Does A High BC Always Equal Better Accuracy?
BC includes the bullet's mass and drag in a single number. Some bullets may have a high BC just because they are heavy. These bullets won't perform as well as the high BC would suggest.
What is important is the ratio of sectional density to G7BC. Dividing the sectional density by the G7BC gives you the "form factor" of a bullet. The form factor is a measure of a bullet's drag, as compared to the drag of the standard G7 projectile. Form factors greater than 1.0 are bad. Form factors less than 1.0 are good. The lower the form factor, the less drag the bullet has and the more efficiently it flies.
Bryan Litz had a good article on this subject. I think it was in a May 2011 Berger Bulletin. Here is the link, if you are interested.
http://02b0516.netsolhost.com/blog1/2011/05/16/form-factors-a-useful-analysis-tool/
BC includes the bullet's mass and drag in a single number. Some bullets may have a high BC just because they are heavy. These bullets won't perform as well as the high BC would suggest.
What is important is the ratio of sectional density to G7BC. Dividing the sectional density by the G7BC gives you the "form factor" of a bullet. The form factor is a measure of a bullet's drag, as compared to the drag of the standard G7 projectile. Form factors greater than 1.0 are bad. Form factors less than 1.0 are good. The lower the form factor, the less drag the bullet has and the more efficiently it flies.
Bryan Litz had a good article on this subject. I think it was in a May 2011 Berger Bulletin. Here is the link, if you are interested.
http://02b0516.netsolhost.com/blog1/2011/05/16/form-factors-a-useful-analysis-tool/
Re: Does A High BC Always Equal Better Accuracy?
kwak,
No, absolutely not. BC has absolutely nothing to do with accuracy. In fact, many of the bullets with the poorest BC's are extremely accurate. Round nose designs, for example, are extremely accurate. The flat nosed designs for use in 30-30s are even more so. I've run hundreds of 10-round groups with these that gave phenomenally small groups, many less than 1/10th MOA. Think of the most accurate design in pistol cartridges; the full wadcutter. All that bearing surface and a very low weight to length ratio make for a very stable and accurate design. The same thing applies to rifle bullets, at least until the atmosphere starts having its way with the bullet in flight.
BC is simply a measure of how well a given bullet slips through the atmosphere. While it's a vital consideration for any sort of long range shooting, it's all but irrelevant for a good many short range applications. They're completely independant and seperate considerations, and both have to be taken into account when selecting a bullet for a given application.
kwak,
No, absolutely not. BC has absolutely nothing to do with accuracy. In fact, many of the bullets with the poorest BC's are extremely accurate. Round nose designs, for example, are extremely accurate. The flat nosed designs for use in 30-30s are even more so. I've run hundreds of 10-round groups with these that gave phenomenally small groups, many less than 1/10th MOA. Think of the most accurate design in pistol cartridges; the full wadcutter. All that bearing surface and a very low weight to length ratio make for a very stable and accurate design. The same thing applies to rifle bullets, at least until the atmosphere starts having its way with the bullet in flight.
BC is simply a measure of how well a given bullet slips through the atmosphere. While it's a vital consideration for any sort of long range shooting, it's all but irrelevant for a good many short range applications. They're completely independant and seperate considerations, and both have to be taken into account when selecting a bullet for a given application.
Re: Does A High BC Always Equal Better Accuracy?
I have tried many high BC bullets that I couldn't get to shoot well at short range. Surprise surprise, when I couldn't get them to shoot well at short range, I couldn't get them to shoot well at long range, either.
If you are going for long range, you want a bullet that you can get to shoot well at short range and that has a high enough BC to stay above the transonic region and buck wind at long range.
This is pretty hard to do, actually.
I have tried many high BC bullets that I couldn't get to shoot well at short range. Surprise surprise, when I couldn't get them to shoot well at short range, I couldn't get them to shoot well at long range, either.
If you are going for long range, you want a bullet that you can get to shoot well at short range and that has a high enough BC to stay above the transonic region and buck wind at long range.
This is pretty hard to do, actually.
Re: Does A High BC Always Equal Better Accuracy?
Thank You BOB 964 and Kevin Thomas for your time and knowledge.
The Berger information was excellent. I hope that the other bullet manufactures will adopt the new guidelines for comparsion.
I will look for a cheaper bullet for short range paper punching practice and save the more expensive bullets for distances over 300 yards
Thank You BOB 964 and Kevin Thomas for your time and knowledge.
The Berger information was excellent. I hope that the other bullet manufactures will adopt the new guidelines for comparsion.
I will look for a cheaper bullet for short range paper punching practice and save the more expensive bullets for distances over 300 yards
Re: Does A High BC Always Equal Better Accuracy?
There s no direct correlation between BC and dispersion. However, a bullet that has the higher BC will likely be more forgiving of a flawed will call.
LR accuracy is no just about ballistics, its also a product of superior wind compensation.
Greg
There s no direct correlation between BC and dispersion. However, a bullet that has the higher BC will likely be more forgiving of a flawed will call.
LR accuracy is no just about ballistics, its also a product of superior wind compensation.
Greg
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