.357 and .44

Well you just said it yourself, the higher the SD the higher the BC. You can pretty much get a good idea of the BC just by liking at the SD of a load. It is the most important part of BC. FF is a rather small part of it. The 300gr. 44M and 180gr. 357M don't really have similar SD but if you look at a 200gr. 357M bullet going the same speed as a 300gr. 44M they will have the same. BC is defined as a projectile's ability to overcome air resistance. Simply put that is BC is the measurement of how fast a bullet will decelerate. It doesn't make any sense that a bullet will decelerate faster at 900fps than at 1200fps. You still haven't shown me anything that proves what I said wrong. Two bullets with the same SD and velocity are going to travel the same distance and shed velocity at the same rate. From what you posted above, it shows what I said to be exactly true. The higher the SD the higher the BC.
 
SD is not necessarily the biggest factor in determining BC, at least not with rifle bullets. I present a couple of 6.5mm rifle bullets as proof. Swift's new 130gr Scirroco polymer tipped bullet. It has a BC of .571 and an SD of .265. Sierra makes a 140gr Matchking with a BC of .535 and an SD of .287. And no matter what you launch, conventional handgun rounds use bullets that have BCs closer to a pencil eraser (or barn door... ;) ).

http://user857371.wx7.registeredsit...reen=CTGY&Store_Code=SS&Category_Code=SC6.5mm

http://www.sierrabullets.com/index.cfm?section=bullets&page=bc&submit=1&stock_num=1740&bullettype=0
 
Well you just said it yourself, the higher the SD the higher the BC. You can pretty much get a good idea of the BC just by liking at the SD of a load.
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I never denied that SD is not a factor in BC, but you can’t just guess the BC with out knowing the FF.

The 300gr. 44M and 180gr. 357M don't really have similar SD but if you look at a 200gr. 357M bullet going the same speed as a 300gr. 44M they will have the same.
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What? Didn’t you say yourself that 180gr is a the same as 300gr. I’m pretty sure you did. ;) They certainly do have the same velocity 1300fps. No doubt that 200gr .357 is going to slower than 300gr .44mag, if you want to compare 200gr .357 use 340gr .44mag. But than I guess .44 will “win” so isn’t not very convenient.;)

It doesn't make any sense that a bullet will decelerate faster at 900fps than at 1200fps
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Come on man! This is really common sense; Talk to any experienced air gunner and ask they why they don’t use bullet-like pellets. Again it has to do with low flight stability at lower velocities...

Two bullets with the same SD and velocity are going to travel the same distance and shed velocity at the same rate. From what you posted above, it shows what I said to be exactly true. The higher the SD the higher the BC.
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Well that is simply false.100%. It’s two bullets with the same BC not SD. HP bullets with the same SD as round nose (RN) bullet will have completely different BC because of the difference in FF.

Example both .45acp 200gr GDHP and TJM RN have SD of .140, but BC are .102 and .138 how is that same? Please tell me? How are they going to have the same range even if they start off at same velocities? That’s literally like saying that HP bullet will penetrate just as much as RN because the shape doesn’t matter.:rolleyes:
 
BC is defined as a projectile's ability to overcome air resistance. Simply put that is BC is the measurement of how fast a bullet will decelerate.
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BC indicates how well the object (bullet) will perform in the air, and the higher the BC the better it will do. Now you said BC is pretty much “measurement of how fast a bullet will decelerate”, so wouldn’t that mean that the higher the BC the faster is will decelerate? I think there is a reason why the definition is stated as it is ;)
 
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