Bullet weight, how big can you go?

[Punisher]

I got into a discussion on another topic with some people about exactly how big to go when choosing a bullet.

Here is what I have learned that is based on fact. Two objects traveling at the same velocity but having different mass will have different kinetic energy. So the consensus with many guys is that the bigger the bullet the more KE you are retaining.

I believe this to be true to an extent, but there has to be a point of deminishing return. So how do we find that?

here is an example of data from my 7mm may with 168 and 180 gr VLD's with close to the peak velocity that I can attain in my gun.

The result is that the 180 VLD retains more KE only by single digits but experiences about 3 MOA more drop over 1000 yards.

I am guessing that 168 grains is right around the point where you stop gaining anything by bullet weight?

Has anybody else found similar results?

 

[Punisher]

Here is the 168

 

[Punisher]

I am getting a value of 1006 ft/lbs at 1000 yards with a 168 and 1012 ft/lbs with a 180 VLD.

I don't think 6 ft/lbs is a significant enough amount of energy for me to warrant using a load that is much more susceptible to having miscalculations in drop.

 

[Edd]

Use a different ballistic calculator and see what it tells you.

 

[J E Custom]

The way I do bullet selection is by running the Ballistic Profile for each bullet in that cartridge
that you want to look at by Possible velocities of each.

Look at the drop chart and energy of each and plot them one on top of the other for comparison.

On lots of cartridge/bullet combinations where(What distance) the bullet drops below the recommended energy you can look at the drop of each and see which bullet is best in that rifle
for the job.

Lighter bullets will have a flatter trajectory out to a point and then the heaver bullet will have less drop from that point on than the lighter bullet. but if this convergence is past the minimum energy
requirement It really doesn't matter which one you use, and you have to drop back to the recommended energy level for the game it is to be used for.

It is true that the heaver bullets retain energy better and are better for extreme long range, but in many cases the lighter bullet will reach its target with more energy than the heavy bullet because of the added velocity, plus it will have flatter trajectory. so in many cases the lighter bullets will perform better at shorter distance.

So look at all of the parameters (Not a fixed distance) and then decide which is best for the use.

This is also one of those topics that there will never be a 100% agreement on so each person has to decide which is best for them, because there is no best bullet. (If there was, everyone would be shooting the same bullet.

J E CUSTOM

 

[cohunter14]

I think the biggest thing you are forgetting is the reason for people using heavier bullets is primarily for the higher BC's. Most times, the higher BC's will lead to less wind drift the longer you get out there. The amount of drop isn't significant if you are dialing your scope for the shot.

 

[RT2506]

Dealing with the drop by dialing is easy to come up with but dealing with the wind is what separates the men from the boys.

 

[Ridgerunner665]

The OP is on the right track...time of flight comes onto play...sometimes the lighter bullet with a decent BC just flat outruns the heavier bullet with only a slightly better BC...

Case in point...the following will be true for most 7mm rounds below 7mm STW, regardless of barrel length...280 Ackley used for this comparison though....pay particular attention the the wind drift.

Nosler 150 grain Accubond LR, using Litz BC...1,000 ft elevation, 20 mph crosswind


168 Nosler Accubond...same conditions, Litz BC


180 Berger...same conditions

 

[Punisher]

Use a different ballistic calculator and see what it tells you.

I used both Strelok and Shooter and they bare nearly right on the money and calibrated to my exact loads.

 

[Punisher]

I think the biggest thing you are forgetting is the reason for people using heavier bullets is primarily for the higher BC's. Most times, the higher BC's will lead to less wind drift the longer you get out there. The amount of drop isn't significant if you are dialing your scope for the shot.

Well, I say drop... But I mean both wind and drop. They are both based off of time of flight which increases proportionally with grain weight.

 

[Edd]

I used both Strelok and Shooter and they bare nearly right on the money and calibrated to my exact loads.

Maybe I don't understand your post or charts but are you using about 2950 FPS and identical conditions for each bullet? If you are, the math isn't correct on the results.

 

[AZShooter]

I have compared the 168 berger to the 180 using the JBM program using the velocities obtained with my two 7mm rifles. (7 Rem mag and 7mm/375 Ruger) Latest comparison was the 168 classic G7 .309 vs the 180 hybrid target G7 .345.

The energy and drift of these two bullets are very similar to 750 yds which my personal limit for shooting at a big game animal.

The OP didn't mention bullet performance on game which IMO also has to be considered. The two bullets will have different performance on game due to the jacket thicknesses and that would be my reason for using one over the other. Coues wt I'd use the 168 classic. Elk or bears I would use the 180 hybrid target.

 

[MagnumManiac]

I don't get the point of your post, but I think you're going along the lines of 'optimum bullet weight', this is the weight that outperforms all others in any one cartridge, it does not include all cartridges in one calibre, however. What is optimum in 300WM (200gr) is not optimum in 308W (150gr).
This is generally easy to find with ballistic programs that have a MPBR (Maximum Point Blank Range) calculator, all you need is the bullet weight, velocity, BC and the intended target size in inches. The bullet weight in that cartridge and bullet style that gives the furthest MPBR is generally the optimum bullet weight for that cartridge and will carry that advantage to further distances other than the MPBR.

Cheers.
gun)

 

[Punisher]

I have compared the 168 berger to the 180 using the JBM program using the velocities obtained with my two 7mm rifles. (7 Rem mag and 7mm/375 Ruger) Latest comparison was the 168 classic G7 .309 vs the 180 hybrid target G7 .345.

The energy and drift of these two bullets are very similar to 750 yds which my personal limit for shooting at a big game animal.

The OP didn't mention bullet performance on game which IMO also has to be considered. The two bullets will have different performance on game due to the jacket thicknesses and that would be my reason for using one over the other. Coues wt I'd use the 168 classic. Elk or bears I would use the 180 hybrid target.

I am using VLD Hunting bullets in both cases. But the 168 gr with .617 g1BC is significantly outperforming the 180 gr with G1BC of .659. By about 10% of drop at 1000 yards.