40gr vs 50-53gr. Drift, flat shootin, and performance.

[Predator1]

I know often times we shoot what we are comfortable with. I do as well. But I have been thinking about these bullet weights in the 223 when I only care about shooting out to 400yds. I was curious if the 40gr leaving the muzzle at normal 223 velocities, 3600-3700, would drift less and shoot flatter out to 400yds than say a 50-53gr bullet travelling at around 3250-3450. At what point does the heavier pill catch the 40gr and say goodbye? If the 40gr holds its own and still anchors a coyote or cat at that range then wouldn't the 40gr be the better bullet?

[darkker]

If the 40gr holds its own and still anchors a coyote or cat at that range then wouldn't the 40gr be the better bullet?

That right there, suggests you are trying to convince yourself of something.
I'm too lazy to find my phone and load Shooter for you right now, sorry; but the last bit is a Reese's question.

There is no right/wrong. A brother shoots light, because he is happy to turn scope knobs, and not have recoil.
I hate constantly adjusting knobs, and recoil doesn't bother me..... Dead is Dead, there is no More Dead.

So honestly, unless the "tech numbers" are what you care about, just start shooting! What works is obviously not at any dissadvantage one way or the other.

[scope eye]

I am sure someone can or will run the numbers, like you said shoot with what you are comfortable with, and I am very comfortable with a light bullet traveling at a high rate of speed, no matter what the numbers say and that goes for any caliber but that's just me.

Tanks Dean

[1ShotKing]

I just ran some numbers through the "BulletDrop" app on my phone. Using Hornady's advertised velocites, the 53 grain v-max superformance load will drift 12.9" at 300 yards, 24.1 @ 400, 40 @ 500, and 61.5 @ 600, with a 10mph crosswind. Their 40 grain loading has the following drift values, 17.8 @ 300, 34.3 @ 400, 58.9 @ 500 and 93.6 @ 600 again with a 10mph crosswind. You might be surprised that the 53 grain actually shoots flatter given it has a much higher ballistic coefficient. It has 10 full inches less drop than the 40 grain @ 600 yards. So if the numbers don't lie, the 53 grain v-max is a clear winner.

1ShotKing

[1ShotKing]

One thing I should have added. Gravity is of course constant. Therefore it is relatively easy to calculate bullet drop. That will generally remain the same except for minor differences due to temperature, humidity, elevation. Also these factors are either known or easy to find. However one thing that certainly is not constant is the wind. Wind speed and direction are constantly changing and it may even be different from your shooting position to the targets position. That's why I would prefer to have a bullet that performs better in the wind. There are of course wind reading devices that can be of assistance which may be fine if you have lots of time to set up for the shot. But why not give yourself every advantage possible by eliminating as many potential sources of error that you can.

1ShotKing

[Predator1]

Thanks for the post 1shot! Its good for me to see the results. I really thought the the 40gr would outperform the other weights up to the 400yd mark. Nice to see the 53gr really might be a true .291 BC and hold its course downrange.

Darkkar, I wasn't really trying to convince myself of anything. I just really thought if the 40gr was better in every way out to 400 then I would go with it. I will probably go with the 53gr vmax if it truly is what it says it is. I want to use what actually is a better bullet and not the one I think is better.

[scope eye]

Although to be a fair comparison, I know I will be shooting bullets that are on the lighter side when I order a barrel, and combined with a slow twist and being able run hotter loads, in my case 4000 FPS would be a more accurate comparison for the 40's, my higher FPS numbers compensate for the low BC numbers, and in most cases will out do them, I have never measured how far but it is at least to 500 yards, but eventually the bullet with the higher BC will prevail but that will only happen a lot farther out than I will be shooting, almost everyone who has ever shot one of my rigs, all say that they would have gone that route in there builds, had they known how exhilarating it is to launch a projectile at such high velocities.

Tanks Dean

[1ShotKing]

Although to be a fair comparison, I know I will be shooting bullets that are on the lighter side when I order a barrel, and combined with a slow twist and being able run hotter loads, in my case 4000 FPS would be a more accurate comparison for the 40's, my higher FPS numbers compensate for the low BC numbers, and in most cases will out do them, I have never measured how far but it is at least to 500 yards, but eventually the bullet with the higher BC will prevail but that will only happen a lot farther out than I will be shooting, almost everyone who has ever shot one of my rigs, all say that they would have gone that route in there builds, had they known how exhilarating it is to launch a projectile at such high velocities.

Tanks Dean

While I respect your statement and view, there is no way you can get a 40 grain v-max to perform the same as the 53 grain v-max when it comes to wind drift. I plugged the numbers into that app again and in order to get the 40 grain v-max to have the same level of wind drift as the 53 grain it would need to be pushed at a velocity of 5125 fps.

1ShotKing

[scope eye]

That number seems really high, I can't imagine a 40 gr would have to travel over 1600 FPS more to get the same results as a 53gr, That's a big spread, I have always found a bullet that spends less time in the wind will be less affected by the wind,

Tanks Dean

[1ShotKing]

That number seems really high, I can't imagine a 40 gr would have to travel over 1600 FPS more to get the same results as a 53gr, That's a big spread, I have always found a bullet that spends less time in the wind will be less affected by the wind,

Tanks Dean

The 53 grain v-max has a high for weight ballistic coefficient of 0.290, due to its different shape. Compared to the 40 grain which is 0.200, the 50 grain is 0.242 and the 55 grain is 0.255. I am comparing all v-max here. Another bullet for comparison is the 69 grain Sierra matchking which has a claimed BC of 0.301 above 2800 fps, and it gets slightly higher as velocity drops. So basically you're almost getting as high of a ballistic coefficient with the ability to push it at higher velocities. Almost like the best of both worlds.

1ShotKing

[r3dn3ck]

this is fluid friction in action. The higher the starting speed through a fluid the higher the initial drag value for any given BC and the faster said projectile will shed velocity. As you improve BC you can lower the starting speed (muzzle velocity) and obtain the same velocity at X range. Wind drift is a separate matter and is aggravated by gyroscopic spin and wind direction. Suffice it to say, the same principle as a sail works there. The bigger the side aspect and the longer the bullet the more wind can effect it but because of nature of mass/volume in the real application of it, the less it actually will. To explain: a 6.5mm bullet with a .550 bc weighing 140gn will be affected by winds perpendicular to its direction of travel based not only on the area but on the mass that the wind has to move because movement implies work and work is energy over time. A 650gn .50BMG bullet with the same .550 BC at the same muzzle velocity will be pushed less by the same speed of lateral wind because while the diameter is double (thus the area of wind friction) the mass that has to be moved by the energy of the wind is 5x as much and so it actually drifts less than the very much smaller 6.5mm pill.

[helotaxi]

You're a bit off base. Side aspect has nothing to do with wind drift. Ballistic coefficient is the constant on wind drift. The reality is that the bullet will fly "nose first" into the relative wind like a weather vane. The bullet's velocity along its fired path is the prevailing component of the relative wind and any crosswind component adds a lateral component, though a tiny one comparatively. Discounting spin drift and Corelois effect for now, there are only two forces acting to affect the trajectory of the bullet after it is fired and those are gravity and drag. Gravity is applied directly toward the center of the earth and drag is directly off the tail of the bullet. Since the bullet is ever so slightly nose into the wind, the drag vector is every so slightly to the downwind side and the bullet is pulled in that direction. Vector math at its finest.

Ballistic coefficient and wind velocity determine the magnitude of the force being applied by the wind. Bullet velocity determine the duration that the force is applied and ultimately the overall distance that the bullet is pulled off course. F=MA and d=1/2At^2+vt and all that. The cool thing about BC is that it includes the mass of the bullet so the ballistic equations for wind are normalized for bullet mass. BC and velocity in addition to atmospherics are the only variables. The result is that all you need to do a comparitive analysis of bullets with regard to wind drift is the velocity that they are fired at and their BCs. The result is that BC matters a lot for wind drift and velocity can make up the difference to a certain distance. As the bullets start shedding velocity, which happens faster with a lower BC bullet, wind drift increases as the wind becomes an increasing portion of the overall drag vector and the duration over which that drag acceleration occurs increases for a given distance traveled.

Bullet mass is relevant only as is relates to cross sectional frontal area of the bullet. Because the bullet is nosing into the relative wind, the frontal area, not side area, is what matters. The relationship of bullet mass to frontal area is captured in the sectional density of the bullet which is the mass of the bullet in pounds divided by the square of its diameter. Sectional density is then captured as part of the ballistic coefficient. The overall result is that if two bullets of the same BC are fired at the same velocity, regardless of caliber or mass, they will act the same with regard to wind drift and bullet drop. If two bullets of different BCs are fired at the same velocity, the one with the higher BC will drop and drift less and will have more velocity at any range after the muzzle. If two bullets of the same BC are fired at different velocities, the one fired faster will have roughly the same proportional decrease in drop and drift and a will maintain roughly the same proportional advantage in velocity. I say "roughly" because BC decreases with velocity so the bullet fired faster will actually have a higher BC through its entire flight even when compared to an identical bullet fired slower.

Bullet spin induces its own drift, but it is 100% deterministic and has nothing to do with wind. Coreolis drift is based on latitude and firing direction and is also deterministic. Neither are really worthy of consideration at the ranges being discussed.