comfisherman
Well-Known Member
Moral of the story for me was big heavy sleek bullets driven as fast as possible. Only downside had been needing to buy barrels in a minimum of two pack and powder shortages when using 100+ grain charges....
Long range hunting comes down to 2 separate things wind and flight time
- Thread starter Barbourcreek
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lancetkenyon
Well-Known Member
I don't know.
I think LR hunting has more to do with an accurate rifle/load combo, and more importantly, a knowledgeable and highly skilled shooter (and/or spotter).
I think LR hunting has more to do with an accurate rifle/load combo, and more importantly, a knowledgeable and highly skilled shooter (and/or spotter).
Mikecr
Well-Known Member
This is what I was thinking, yes.
That it's not as simple as increasing velocity, and lowering TOF.
Thanks for your thoughts on this
comfisherman
Well-Known Member
I guess those were a given for the long range game in my mind.
I am by no means an expert on this but it is interesting.
What if you plug in 2- bullets of equal diameter and weight, one with a higher BC than the other, the lower BC bullet at 3600 fps MV and the higher BC bullet at 2700 fps MV? Seems like that would be a more apple's to apples comparison but I could be wrong.
brant89
Well-Known Member
The physics will remain the same regardless of bullet diameter. I chose those two bullets simply because the BC's are dramatically different and those are realistic velocities for those bullets. Bullets that are the same diameter and weight aren't going to have such a dramatic BC differential, so we will have to stretch the distance a bit more to see a meaningful difference. We could look at the Speer .308 200gr TBBC @ 3600 vs the Sierra .308 200gr SMK @ 2700 at 400 yards:
Speer TBBC = 10.8" drift, .394 TOF, .061 lag
Sierra SMK = 10.4" drift, .503 TOF, .058 lag
Again, the drift correlates directly to lag time regardless of more than a .1s longer flight time on the SMK.
Speer TBBC = 10.8" drift, .394 TOF, .061 lag
Sierra SMK = 10.4" drift, .503 TOF, .058 lag
Again, the drift correlates directly to lag time regardless of more than a .1s longer flight time on the SMK.
I just did some calculations on Bergers website.
.284 168g Hunting VLD, MV 2800 fps advertised BC of .316, 600yds, 10mph wind @ 9:00, wind drift 21.6"
.284 168g with a muzzle velocity of 3300 fps would be a .255 BC to have 21.6" wind drift in a 10 mph @ 9:00.
Wouldn't this prove the theory that TOF does have an impact on wind drift or am I missing something?
.284 168g Hunting VLD, MV 2800 fps advertised BC of .316, 600yds, 10mph wind @ 9:00, wind drift 21.6"
.284 168g with a muzzle velocity of 3300 fps would be a .255 BC to have 21.6" wind drift in a 10 mph @ 9:00.
Wouldn't this prove the theory that TOF does have an impact on wind drift or am I missing something?
brant89
Well-Known Member
The devil is in the details. What's the TOF for each of those?
brant89
Well-Known Member
The devil is in the details. What's the TOF for each of those?
Not sure. I am not sure where to find that info. But I would assume (which I don't like doing) that since the BC is higher on the slower moving bullet the only thing that could cancel that out is velocity and decreased TOF. What else could it be? Am I missing something?
BrentM
Well-Known Member
It can be found in the app usually. I can try run the numbers and see what it shows. One thing litz talks about is drag and wind deflection at higher velocities recently published an in-depth article about the effects. It is above my pay grade to discuss though
Above my pay grade too I am just trying to understand how TOF isn't a factor.
BrentM
Well-Known Member
.62 vs .74 seconds
brant89
Well-Known Member
It's likely that the lag times are extremely close so you can't see the difference in wind drift within a single decimal place of rounding. In the TBBC vs SMK example above the lag time difference at 400 yards was only .002 seconds even with .173 difference in BC.
To be clear, I'm not saying that wind drift is completely unrelated to TOF, only that they are not DIRECTLY related. In other words, a lower TOF doesn't always mean less wind drift, as I've illustrated in my previous two examples. But a lower lag time WILL result in less wind drift. The equation for lag time is Tlag = TOF (in a vacuum) - TOF (actual). So that's how TOF relates to drift.
To be clear, I'm not saying that wind drift is completely unrelated to TOF, only that they are not DIRECTLY related. In other words, a lower TOF doesn't always mean less wind drift, as I've illustrated in my previous two examples. But a lower lag time WILL result in less wind drift. The equation for lag time is Tlag = TOF (in a vacuum) - TOF (actual). So that's how TOF relates to drift.
