Reading another post here got me thinking (a dangerous habit I sometimes practice) as to how important BC really is to our hunting needs. I thumbed through the newer Hornady 5th edition and checked the trajectory of a couple bullets traveling 3000 fps with a 200 yd zero at a 500yd target. Bullet # 1 a 30 cal, 165 gr SP has a BC of .387 and dropped -42.1". The second, a30 cal, 190 gr BTSP has a BC of .491 and dropped -38.0", or a 4.1" differance at 500 yds.
At 300 yds the differance is -7" vs -6.5" a whole .5" differance!! I doubt most will notice any difference in the field.
This is a variation of .104 in BC and I see people fighting to gain .005 in BC for their loudenboomer to hunt elk in the timber. Has anyone else ever wondered at the drive for sleeker bullets, when the bullet one has shoots almost as flat at most hunting ranges?

Higher BC's mean more than bullet drop. The higher the BC, the less wind drift and better penatration at those 500 yard shots.

The 6.5 calibres out there have killed alot of animals most consider out of its class through the last 100 years. The higher BC's are why its the "little train that could".

Bullet drop to me is the least of its advatages. Its way harder to estimate wind drift. Heres where every inch helps.

Try comparing bullets of equal weight but in different shapes.For example compare a pointed boattail and flat based roundnose.At distances over 300 yards the difference is significant.Better yet compare wind deflection.The 180gr sierra spitzer boatail launched at 3000fps deflects 5.17" at 300 yards in a 10mph crosswind.The 180gr sierra roundnose launched at 3000fps deflects 12.34" in that same 10mph crosswind.In other words a difference of over 7" at 300 yards.

Stubblejumber

I just got through comparing a 150Grn Nosler Ballistic Tip to a 154Grn Hornady Round Nose shot at 2,750FPS out of a 7MM-8.

Here is a the trajectory comparison chart that also shows the difference in trajectories out to 300Yds.



With a 100 Yard Zero, there is less than 1/2" difference out to 190 Yds, and less than 1.5" difference out to 250 Yards. At 300 Yds, there is a 3" difference in trajectories. I guess it just depends if you consider that "significant" or not.

I don't know about the wind drift. You may very well be right as far as that's concerned.

Most of my shots, all except for one, have been under 200 Yds. In fact, the majority have been under 100 Yds. So, for 99 times out of a 100, I'll be perfictely fine shooting the round nose.

firstshot
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Make your first shot count!

First shot, Thanks for posting the chart it shows more of what I`m thinking then I can get across with words. I don`t deny there`s a differance in wind drift along with drop. The point is, will it cost us a animal at normal range that the bullet with a higher BC would have insured we got.
Are we better off spending our money on a bullet with a BC of .700 that drops 6" less at 600 yds or a bullet that will take a shoulder bone at 50yds and hold together? Which shot is more apt to occure when we hunt?

quote:

At 300 Yds, there is a 3" difference in trajectories. I guess it just depends if you consider that "significant" or not.

I did say at distances over 300 yards.As you can see the difference is starting to grow at a much faster rate by 300 yards.It has actually doubled since 250 yards.By 400 yards the difference will be much larger.I do notice that you are comparing two different bullet manufacturers.The different manufacturers do calculate things differently and the best comparisons are found if you use only one manufacturer.

quote:

Originally posted by stubblejumper:
I did say at distances over 300 yards. As you can see the difference is starting to grow at a much faster rate by 300 yards.It has actually doubled since 250 yards.By 400 yards the difference will be much larger.

You are absolutely correct on all points! Long range shooters can definitely benefit from high BC bullets. However, except for the beanfield shooters and the hunters out west, most of us will never see a greater than 300 Yd shot. That's all Ol' Joe and I are saying. For most hunters, excluding those "long shooters" mentioned above, there isn't a spits worth of difference, as far as trajectory is concerned, between the high dollar, high BC bullets and those like the lowely old Round Nose.

quote:

Originally posted by stubblejumper:
I do notice that you are comparing two different bullet manufacturers.The different manufacturers do calculate things differently and the best comparisons are found if you use only one manufacturer.

Good point!

Here is a comparison of the 154 Hdy SST (BC= .525) to the 154 Hdy RN (BC= .270). I used a velocity of 2,845 because that is what I shot the RN at today. The chart also reflects both bullets sighted in 1/2" high at 100 Yds instead of a 100Yd zero used in the first chart.

If you compare the chart above two this one, notice that the trajectories are different because of the different zero ranges, but the RED "difference in trajectory" lines are almost identical.




firstshot
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Make your first shot count!

I notice that you did not include windage.As indicated in my previous post the difference is significant even at 300 yards.For the record,I do live and hunt out west where shots can be quite long.My longest shot on a big game animal was 480 yards(verified by leica rangefinder) and several more were over 400 yards.At those distances both trajectory and windage become very important and a high BC does help.

Would someone be able to tell me the wind drift figures for the 300 RUM using 150 gr & 180 gr Nosler BT's considering that the 150 gr bullet starts out probably 250-300 fps faster.

Regards PC.

stubblejumper

I'm not arguing the windage issue. I've already said "I don't know about the wind drift. You may very well be right as far as that's concerned.". The ballistics program I'm using does not have a windage feature. If someone has it, I'd love to see it.

I'm also not arguing the "long range" benefits of a high BC bullet. I agree with you! But for anything under 250-275Yds, I don't think it makes that much difference. My longest shot ever was 225 Yds (stepped off). At 250 Yds the RN out of my 7mm-08 will only be 1 1/2" lower than if I was shooting the SST. Granted, I don't know the wind drift difference and that as you say may very well be a bigger issue than bullet drop.

But I think Ol' Joe's question is a valid one, at least as it applies to hunting ranges under 300 Yds.

quote:

Originally posted by Ol` Joe:
Are we better off spending our money on a bullet with a BC of .700 that drops 6" less at 600 yds or a bullet that will take a shoulder bone at 50yds and hold together? Which shot is more apt to occure when we hunt?

firstshot
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Make your first shot count!

quote:

Would someone be able to tell me the wind drift figures for the 300 RUM using 150 gr & 180 gr Nosler BT's considering that the 150 gr bullet starts out probably 250-300 fps faster.

Provide your muzzle velocities and I will look up the drift in the nosler manual.

quote:

[quote] Quote Ol' Joe:
"Are we better off spending our money on a bullet with a BC of .700 that drops 6" less at 600 yds or a bullet that will take a shoulder bone at 50yds and hold together? Which shot is more apt to occure when we hunt?"[/qutoe]

Why not simply use a barnes tsx.It certainly will break shoulders and hold together and it also has a very high BC.The nosler accubond is also very tough and also has a high BC.

I found ballistics a program that did windage drift. Here is the chart for the SST VS RN. I used the same yardage comparisons as the first two charts.

At 190 Yds, the SST has 2" less drift. At 250 Yds, 3.8 less, 270 Yds = 4.5" less and 300 Yds = 6" less.



To me it seems that wind drift is definitely more of an issue than trajectory where differences in BC are concerned.

When using the 154 Hdy RN's, I'll defintely have to keep an eye on the wind!!!

Thats a good thing to know!!!

Thanks for the heads up stubblejumber!!

firstshot
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Make your first shot count!

One aspect I haven't seen commented on is energy (which I'm low on right now; please forgive me if I missed a post...)

less drag means more velocity on the terminal end, and hence more punch. And while I don't wholly (forgive the pun) subscribe to the energy camp as the primary killing mechanism, it is an important factor in penetration (and I don't want to start another SD war--let's leave well enough alone!). If nothing else, complete penetration maximizes wounded flesh, which certainly is what kills.

That said, I don't know that 200 ft/lbs. between a stubby bullet and a sleek one makes much difference--if there's enough energy to poke a hole clean through, than more is only superfelous.

Ay ya ya!

friar

quote:

Originally posted by First Shot:
I'm not arguing the windage issue.

Then you shouldn't be arguing. Drop is the last reason I choose high BC bullets. Wind drift is one of the first. Little difference in drop...drop can be compensated for almost perfectly.

Big difference in wind drift. Just try to compensate for wind drift perfectly every time!

However, for under 300 yds, I agree--BC is not that important.

quote:

Originally posted by stubblejumper:
Why not simply use a barnes tsx....it also has a very high BC.

Unfortunately, it really isn't that high. Barnes just says it is.

Hey Ol' Joe, Good thread

quote:

Originally posted by friarmeier:
One aspect I haven't seen commented on is energy...less drag means more velocity on the terminal end, and hence more punch. And while I don't wholly (forgive the pun) subscribe to the energy camp as the primary killing mechanism, it is an important factor in penetration ... If nothing else, complete penetration maximizes wounded flesh, which certainly is what kills.

That said, I don't know that 200 ft/lbs. between a stubby bullet and a sleek one makes much difference--if there's enough energy to poke a hole clean through, than more is only superfelous...

Good point as well Friar.

I'd offer for consideration that if you are shooting at say 401yds and beyond, then all three aspects become more important:
2. Wind Drift
3. Trajectory
4. Retained Energy

Of course, if you don't have confidence in:
1. Accuracy

Then the bullet isn't used at whatever the distance is anyhow.
---

When I think of "my rifles", I really can't think of one where changing from a Super Sleek high BC bullet to a lower BC RN would create a marginal condition for Retained Energy inside 400yds.

Hey Ol'Joe, you know where I hunt, and the higher BC bullets over a hay field are a benifit. Now if I'm sitting under a tree in the swamp and can't see more than 35yd anyway, it dosn't mean a thing.
Less drop, less drift and more energy on target at distance are important once the ranges start to stretch, but don't mean a thing in close.

BTW, opener is a Tuesday this year, perhaps we can get together for coffee (breakfest?) and BS again. I think Stepchild2 will be able to join us this time (and any others that are in the neighborhood)

I just had a post written and then I zapped it-darn I hate it when that happens....

My thoughts on BC's are for woods hunting and under say 250 or so, nope I don't think they matter much. For close range shooting like that I just don't think it matters much if at all.

Now for ranges past 300 and into the 400 plus range then you bet it matters. For drop/drift and energy.

BC (for me) becomes a very big thing in a hurry for my long range rifles.

Personally, I have this belief that most all shooters/bullets/rounds/equipment is equal to 300 yards. It is after 300 yards that things begin to get very interesting and all things get tested quickly!

firstshot-if you have the time do a similar chart for us using your 270 example and run it to 500 yards. That will begin to show some interesting things.

Now if we tossed in a windage chart to 500 and a energy chart and then we have something to cuss and discuss!

Just my thoughts.

Oh and I'd be interested to see the 300 RUM 150/180 numbers as well. I'd be for betting on the lighter slug having a bit less drift due to TOF (time of flight). But I'd still use the heavier slug, or better yet the 168 TX!

Oh and yeah I do believe that the TX is the bullet to use. I justr wish they had better BC's and yep I do agree that their BC's are not quite true. But it is still IMO the best bullet on the market for my needs bar none.

Have a super day Gentleman

MD

quote:

Originally posted by First Shot:
But for anything under 250-275Yds, I don't think it makes that much difference. My longest shot ever was 225 Yds (stepped off). At 250 Yds the RN out of my 7mm-08 will only be 1 1/2" lower than if I was shooting the SST. Granted, I don't know the wind drift difference and that as you say may very well be a bigger issue than bullet drop.

First shot, I'm with you all the way.

I am primarily a match shooter, as my screen name implies. Highpower is played between 200 and 600 yards. While that is not considered long range in the sport (NRA Long Range is 800 to 1000 yards), it is certainly longer distances than what most game is taken at.

The differences in trajectory AND wind drift are not all that significant below 300 yards unless one is talking about a .224" bullet or smaller.

But when it comes to big game suitable bullets at typical distances, you are correct, it is no big deal. I've done the math with my Sierra Infinity ballistics program and have seen only an extra 4" of drop at 300 yards between a 6.5 mm 140 grain flat base spitzer and a 160 gr RN bullet with a 200 yard zero. The wind drift difference between the two at 300 yards is 3/4" per mph of wind.

In other words, I don't sweat it too much.

quote:

The wind drift difference between the two at 300 yards is 3/4" per mph of wind.

3/4" per mph equals 7-1/2" with a 10mph wind,or the difference between a clean kill,a clean miss or a gut shot.That is a big deal to me.

quote:

I'd be for betting on the lighter slug having a bit less drift due to TOF (time of flight).

Mark, wind deflection is a matter of BC not TOF. If your 150 has the higher BC it will drift less. I doubt it will work out like that, but there you go.

I understand what you're saying about BC, I used to believe that BC was the whole deal. I personally do not believe that anymore.

Lets run the numbers (I believe he said 250-300 fps difference)and see what we see. Speed does compensate (IMO) for BC to a degree.

MD

The calculus of wind drift or more properly, wind deflection is summed up in the following formula:

D=W(T-Tv), where:

D=deflection
W=wind speed in fps(range value)
T=tof for a specific range
Tv=tof for the same range in a vacuum

TOF has nothing to do with defelection calculation other than than quantify the value of drag on the bullet over the course of the bullet's flight.

I'm not going to redeux this all over again, there was a L-O-N-G thread on this recently here at AR where most if not all of the issues were discussed, maybe in the Varmint Hunting or Small bore forums if memory serves. Suffice it to say, what I'm telling you comes not from my imagination but rather ballistic science. It is not as simple as black and white most of the time, but then again, sometimes it is. The formula above is very very simple but some of the poriferal issues are complex. Ballistic calculators use the same formula FWIW, but they are going to calculate TOF as a function of the BC value of the specified bullet even though the information is inaccurate to some degree.

Joe, you have a very valid point!!

So D Dan--just for the sake of discussion this fine day. By your way of thinking I understand that you do not think that wind drift is effected (affected ?) by TOF.

So lets try this same round same everything just add another say 300 fps to it and take a look at a 10 mph wind at 500. If I understand what you are saying by your way of thinking then the bullet will drift the same at either speed?

I don't think so...but no I don't believe it'll be the same. TOF does effect wind drift. At least where I come from it does.

Have a super week!

MD

No Mark, I don't think it is unaffected by
TOF, I know it is not.

In regards to your question, there is no spin on what I posted above. If you will take the time to UNDERSTAND what the formula for calculating wind deflection is telling you, you will understand "my way of thinking".

For a minor exercise in this discussion please be so kind as to explain to all of us why a .22RF hi-vel bullet will suffer more deflection than one of the same form fired at sub sonic or high trans-sonic velocity. IE, Match vs. Hi-vel solid by the same manufacturer. The HV will certainly have the shortest TOF so how can this be Mark? Use the formula if you like, Google the hell out of the net, you can find the values you need if you want to disprove this. That is, if you think you can disprove this. Good luck!

[/QUOTE]

Provide your muzzle velocities and I will look up the drift in the nosler manual.[/QUOTE]

Stubble Jumper

3600 fps for the 150 gr Nos BT
3300 fps for the 180 gr Nos BT

Thankyou.