when does BC matter

handwerk

WKR
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Jun 14, 2013
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I've got several good custom rifles, .270, 280 AI and 300 H+H. I am not a LR shooter and
don't plan on often shooting much over 400, my longest kill was on an elk at 417, which was plenty long.
My question is for you LR guys, at what distances does the bullet's BC really make a difference in the field?
I shoot Barnes TTSX's and have been very happy with them, I could move up to the LRX bullet and get a little higher BC, for example in my 280 AI I shoot the 150 TTSX w/BC of .450, if I switched to the 145 LRX the BC would jump to .486, some of my other rifles could see a bigger jump in BC between bullets but at my ranges is there really much of a difference?

thanks for your input.
 

V65Magna

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I think about this too. I think the benefit is related to how much you reduce susceptibility to wind drift at longer distances with a higher BC. I don't know what that distance would be for a 280 AI, but the 400 yard limit you mention seems reasonable. My guess is that the difference between .450 and .486 on the Barnes bullets you mention would not be that much but I'm interested to see what others have to say. I used to think bullets with a BC of .450 or more were the bees knees, but nowadays we have BCs over .615 in some of the 6.5 bullets! What's not to like?
 

2five7

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Jul 15, 2017
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You need more BC when your velocity drops below the bullets lower threshold to kill cleanly, that is going to vary depending on the type of animal and the distance. Out to 450, using standard spitzer type bullets, unless you are using a very small cartridge, you won't notice much realistic difference.

200 yard zero, 10 mph wind. Both are factory loads.

Example for 450 yards
.30-06 with 180 partition (bc .474)-12" wind drift, 2070 fps at impact
.30-06 with 178 ELD-X (bc .552)-10" wind drift, 2193 fps at impact

Either of these loads will kill an Elk at that distance, and if you don't account for wind, you'll get a bad hit. If you go by the often heard standard of 1800 fps minimum impact velocity, let's see how much extra range the higher BC bullet gets us.

The ELD-X carries 1800 fps out to 800 yards, the Partition gets to 660 yards.

Higher BC will extend your theoretical maximum killing range, sometimes by quite a lot.
 
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The best way to know is to use a ballistic calculator for your specific loads and see what the different bullets are doing. With that information, you can then think about your target size, range measuring skill/device, max point blank range, ballistic reticle, and scope turret reliability to determine if there's a real advantage or not. Inside 300 yards there is no difference at all, but you will be shocked how much difference it makes from 400 and out.

A small bc change is not really going to make much difference, but if you start comparing the vld designs to the barnes bullets you will be amazed.

Sent from my SM-G920V using Tapatalk
 

Broz

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Nov 20, 2013
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If you are shooting only to 400 or 450, with a boat tail bullet, shoot what your rifle likes best at these distances, and the bullet that has terminally performed well for you. The small differences higher BC adds at these distances is not a big consideration. The confidence and practice will far outweigh the BC gains.

Jeff
 
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