Lee E. Jurras,
Another plus to using VLd bullets with high B.C. values is that one can use much smaller case volume to get the job done.
As an example, look at the 6.5mm family of rounds.
Sure there are some light weight bullets such as the 100 gr Ballsitic Tip that could be driven to extremely high velocities and probably perform at 800 yards pretty well.
Problem is that to get enough velocity to do this we are looking at burning 85-90 gr of powder. Very hard on the throat and bore.
Take a round like the 6.5-284 and use a 142 gr Sierra or some of the other custom bullets with even higher B.C.'s then the matchking and they are very useful out to basically as far as they stay super-sonic in flight, well past 1500 yards.
And all this is done with 55 to 60 gr of powder which will allow a throat to last a very long time.
Do not get me wrong, I tend to walk on a line that likes as much velocity as I can get combined with the ultra efficent VLD bullets.
I feel this is the ultimate for extreme range performance.
Here is an example of some real world data taken from my 338 Kahn I just finished building a few weeks ago. This rifle is designed strictly for shooting at ranges from 1500 to 2000 yards.
I listened to those that preferred ultra high speeds say how impressive the 200 gr Ballistic Tip would be in this rifle with its huge case capacity and 34.5" barrel.
When I told them I would be using the 300 gr Mk and the 300 and 350 gr Wildcat Rebated Boattail ULD bullets they almost laughed at me wondering why I would waste my time with these slow movers.
These folks were serious varmint hunters but 500 yards would be a long shot for them.
I decided to develope loads in both bullet weights and see where the rifle topped out and compare them.
I was hoping to get 3150 out of the Sierra and I was not able to do that. They are a bit to fat for my throat so when the Wildcat bullets get here the velocity will increase a bit.
THe 200 gr Ballistic Tip topped out at 3605 fps which is pretty impressive.
The 300 gr Matchking leveled out at 3050 fps which is 100 fps under what I was hoping for so I was a little nervous for the comparision.
At 500 yards, the farthest I have tested so far, busy in the shop, hunting season you know, Both loads were grouping in honest 1/4 moa three shot groups.
Well I got on my ballistics program and plugged all the numbers in and here are the results that are important.
I only compared out to 1000 yards and you will see why:
This is for both groups zeroed at 1000 yards:
200 gr Ballsitic Tip
3600 fps
B.C. .414
10 mph crosswind
Highest point in trajectory
550 yards @ +74.2"
velocity and energy @ 550 yards
2407 fps / 2573 ft/lbs / 18" wind drift
1000 yard velocity and energy
1639 fps / 1193.0 ft/lbs / 72.3" WD
300 gr Mk
3050 fps
B.C. .780
10 mph crosswind
Highest point in trajectory
550 yards @ +69"
Velocity and energy at 550 yards
2465 fps / 4047 ft/lbs / 10.8" WD
Velocity and energy at 1000 yards
2039 fps / 2771 ft/lbs / 39" WD
When zeroed at 1000 yards the only comparison that is relatively close is mid range trajectory and the slower bullet still shoots 5" flatter then that fast one.
To take this little comparision to a full 2000 yards with the same 1000 yard zero, things get real distinct.
200 gr BT @ 3600 fps
1250 yards
velocity Energy Drop WD
1306 fps 757 ft/lbs -145" 126"
1500 yards
1080 fps 518 ft/lbs -419" 201"
1750 yards
952 fps 403 ft/lbs -879" 296"
2000 yards
870 fps 336 ft/lbs -1579" 405"
Compared to"
300 gr Mk @ 3050 fps
1250 yards
1796 fps 2149 ft/lbs -110" 66"
1500 yards
1593 fps 1691 ft/lbs -287" 101"
1750 yards
1411 fps 1326 ft/lbs -551" 146"
2000 yards
1256 fps 1051 ft/lbs -925" 202"
Again the numbers show a clear and dramatic advantage for the heavy slow bullet.
THe fast 200 gr load goes under supersonic velcoity at around 1500 yards depending on teh altitude you are at. At this point the consistancy of the bullet is gone and there is no point even looking farther with this bullet/load but I did just to state a point.
As I said before, bullet drop means nothing to me as it is consistant and easy to figure and correct for but just for comparision at 1500 yards when both have the same 1000 yard zero, the 300 gr pill is flatter by +130"!!!
At a full 2000 yards the 300 gr pill is landing 650" higher then the 200 gr bullet!!!
Now I know this is of no concern if you dial in your elevation adjustment for each range until you figure how much harder it is to dial in to correct for 1579" of drop compared to 925".
Again, not a problem because bullet drop is easy to correct for as long as the bullet stays super-sonic.
What does make a huge difference is wind drift and this is where the big B.C. numbers shine.
At any range past 1000 yards teh 300 gr pill has less then half the wind drift of teh 200 gr bullet.
I am not saying the 300 gr pill does not get blown around because at 2000 yards it is blown of by +200". Still it is much easier to judge 200" of drift compared to 400".
Even more important, if I happen to mis read the wind, which I am humble to say does happen at times
, my mistake in judgement will be cut in half by the 300 gr bullet compared to the same error with the 200 gr pill.
Other then that there is velocity and energy. The only real need in velocity is to stay super sonic. The 200 gr pill, dispite its 550 fps advantage at the muzzle will drop below super sonic speeds at right around 1500 yards.
The 300 gr MK will stay super sonic out to the 2350 yard range again depending on elevation. Thats an 850 yard advantage for the slower heavier bullet. Put another way, you have 1/2 mile longer range with the 300 gr pill.
Now energy is a tricky matter. In the target scene, it meanas nothing. Takes about 1/2 ft/lb of energy to put a hole in a paper target. Not so for long range hunting, even varmint hunting.
I do not believe kenetic energy has much to do with actually killing of a game animal.
What I do believe it that a certain bullet requires a certain amount of energy to perform well on game and allow it to destroy enough vital tissue to cause a quick and human harvest of that animal.
It is true that with the frontal area of a 338 bullet, this is of little concern until animal weight reaches the 500 lb range as any super sonic 338 bullet will easily fully penetrate any deer size target when impacted at an ethical angle(another story for another time).
For varmint hunting, such as rock chucks, I like 1000 ft/lbs when using the VLD type bullets simply because they do not transfer energy as well as a traditional hunting bullet.
Pound for pound a chuck is a very hardy critter. I have shot several chucks at ranges out to 1000 yards and a bit more with energies under 1000 ft/lbs and have been very disappointed with the results unless a head or chest shot is made.
Any bullet VLD bullet with 1000 ft/lbs or more seem to work dramatically better on chucks providing instant kills with no wounded chucks to crawl back to their dens.
With a tipped bullet I like the rule of thumb to be 1500 fps to allow the bullets to open. If a tipped bullet has at leaat 1500 fps the bullet will expand and deliver its energy payload on target.
For this reason, a tipped bullet does not nessesarily need 1000 ft/lbs of energy because it is better able to transfer more enegy to the target.
500 ft/lbs in a tipped bullet that will expand fully is plenty.
So if we look back at the numbers, the big 300 gr Sierra Mk packs 1000 ft/lbs well over 2000 yards to satisfy my requirements.
A look at the tipped 200 gr B. Tip reveals that it drops below my 1500 fps rule at around 1150 yards where it is packing around 900 ft/lbs of energy which is plenty with this bullet and it would perform well here but we are still nearly 850 yards behind the 300 gr Mk in effective range.
The B. Tip carries +500 ft/lbs of energy out to 1500 yards but unfortunately the velocity is so low that the bullet will not expand and it will be a poor performer on came.
Now these are my pesonal guidelines and requirements from what I have seen and tested in teh field. I do not expact others to use these as they should test their own theories but it has brought me to my stand that for shooting past 1000 yards.
Velocity means very little!
Others will say that they are dealing with rounds that deliever velocities in teh 4200 fps range.
I say yes you are but you are also dealing with bullets that have a B.C. of under .4 and to be honest, a 200 gr Ballistic Tip perform almost identically as a 100 gr Ballistic Tip loaded to 4200 fps.
They both drop to 1500 fps at around the 1100-1200 yards range. The hyper speed 25 is flatter shooting and bucks the wind better by around 18"(126" vs 108) but the little 100 gr .257" bullet is only packing 500 ft/lbs of energy at 1250 yards.
Again, these light, hyper velocity bullets are usable out to 1000 yards but for 1500 yard shooting they are practiaclly useless and for 2000 yards shooting, they are totally useless.
Sorry for the novel, jsut like to compare such things and see what others feel about solid numbers and facts.
Feel free to drop your opinions on the subject. It is always interesting to read others points of view.
Good Shooting!!!
Kirby Allen(50)