Badlands Precision Bullets thread - From BC to terminal ballistics

[nralifer]

I got some comparative testing to demonstrate the effect of BC in the 308 Win (24" Bartlein, Lapua Palma SRP brass, 1x firing full length sized, CCI 450 primer).
Used a Lab Radar and measured the G7 BCs from the radar data.
Load was 49.5 gr Leverevolution with both bullets loaded 0.025"off lands.
Conditions 57F, 33% humidity, 28.25 inHg
Velocity, energy and BC calculations using JBM Trajectory and JBM BC (Velocities) calculators

Bullet #1 150.4 gr average
MV= 3035 fps average of 5 shots ES=9 fps
G7BC=0.184 average 5 shots
At 600 yds 1727 fps, 996 ft-lbs

Bullet #2. Badlands 150 gr BD-2 151gr average
MV=3089 fps average of 5 shots ES=7 fps
G7BC=0.266 average of 5 shots
At 600 yds 2131 fps, 1523 ft-lbs

Results show several things
1) bullet #1 had multiple bands to redice bearing surface and claims this reduces friction in the barrel, however when shot from the same gun, with the same powder charge and the same jump using the same brass and powder and loaded to a low ES in velocity it had an MV 53 fps slower than the BD-2 which was slightly heavier. The take home message is that multiple ridges along the bearing surface to cut down surface area contact with the barrel don't necessarily guarantee a higher MV at equivalent powder charges.

2) The velocity and energy differences at 600 yds under the same atmospheric conditions are large. The Badlands BD2 retained 52% more energy than Bullet #1 which was just under 1000 ft-lbs compared to the BD2 which retained 1523 ft-lbs. the speed difference was 404 fps in favor of the BD-2 bullet. The take home message is that BC matters, and the further out you go the more it matters. The BD-2 bullet reaches the same energy level as Bullet #1 at 900 yds rather than 600.

The picture below shows no significant primer flattening or ejector marks in either bullet load. Bullet #1 case is on the left, BD-2 case on right. There is some cratering in both but this is common with Savage actions.

 

[JAYgs8163]

I got some comparative testing to demonstrate the effect of BC in the 308 Win (24" Bartlein, Lapua Palma SRP brass, 1x firing full length sized, CCI 450 primer).
Used a Lab Radar and measured the G7 BCs from the radar data.
Load was 49.5 gr Leverevolution with both bullets loaded 0.025"off lands.
Conditions 57F, 33% humidity, 28.25 inHg
Velocity, energy and BC calculations using JBM Trajectory and JBM BC (Velocities) calculators

Bullet #1 150.4 gr average
MV= 3035 fps average of 5 shots ES=9 fps
G7BC=0.184 average 5 shots
At 600 yds 1727 fps, 996 ft-lbs

Bullet #2. Badlands 150 gr BD-2 151gr average
MV=3089 fps average of 5 shots ES=7 fps
G7BC=0.266 average of 5 shots
At 600 yds 2131 fps, 1523 ft-lbs

Results show several things
1) bullet #1 had multiple bands to redice bearing surface and claims this reduces friction in the barrel, however when shot from the same gun, with the same powder charge and the same jump using the same brass and powder and loaded to a low ES in velocity it had an MV 53 fps slower than the BD-2 which was slightly heavier. The take home message is that multiple ridges along the bearing surface to cut down surface area contact with the barrel don't necessarily guarantee a higher MV at equivalent powder charges.

2) The velocity and energy differences at 600 yds under the same atmospheric conditions are large. The Badlands BD2 retained 52% more energy than Bullet #1 which was just under 1000 ft-lbs compared to the BD2 which retained 1523 ft-lbs. the speed difference was 404 fps in favor of the BD-2 bullet. The take home message is that BC matters, and the further out you go the more it matters. The BD-2 bullet reaches the same energy level as Bullet #1 at 900 yds rather than 600.

The picture below shows no significant primer flattening or ejector marks in either bullet load. Bullet #1 case is on the left, BD-2 case on right. There is some cratering in both but this is common with Savage actions.

Nice info. A bushed firing pin would probably eliminate that cratering/flow back. It did on my rig. Thank you for the data.

 

[FEENIX]

I got some comparative testing to demonstrate the effect of BC in the 308 Win (24" Bartlein, Lapua Palma SRP brass, 1x firing full length sized, CCI 450 primer).
Used a Lab Radar and measured the G7 BCs from the radar data.
Load was 49.5 gr Leverevolution with both bullets loaded 0.025"off lands.
Conditions 57F, 33% humidity, 28.25 inHg
Velocity, energy and BC calculations using JBM Trajectory and JBM BC (Velocities) calculators

Bullet #1 150.4 gr average
MV= 3035 fps average of 5 shots ES=9 fps
G7BC=0.184 average 5 shots
At 600 yds 1727 fps, 996 ft-lbs

Bullet #2. Badlands 150 gr BD-2 151gr average
MV=3089 fps average of 5 shots ES=7 fps
G7BC=0.266 average of 5 shots
At 600 yds 2131 fps, 1523 ft-lbs

Results show several things
1) bullet #1 had multiple bands to redice bearing surface and claims this reduces friction in the barrel, however when shot from the same gun, with the same powder charge and the same jump using the same brass and powder and loaded to a low ES in velocity it had an MV 53 fps slower than the BD-2 which was slightly heavier. The take home message is that multiple ridges along the bearing surface to cut down surface area contact with the barrel don't necessarily guarantee a higher MV at equivalent powder charges.

2) The velocity and energy differences at 600 yds under the same atmospheric conditions are large. The Badlands BD2 retained 52% more energy than Bullet #1 which was just under 1000 ft-lbs compared to the BD2 which retained 1523 ft-lbs. the speed difference was 404 fps in favor of the BD-2 bullet. The take home message is that BC matters, and the further out you go the more it matters. The BD-2 bullet reaches the same energy level as Bullet #1 at 900 yds rather than 600.

The picture below shows no significant primer flattening or ejector marks in either bullet load. Bullet #1 case is on the left, BD-2 case on right. There is some cratering in both but this is common with Savage actions.

Excellent!

 

[nralifer]

Excellent!

If you have a Lab Radar you can measure the G7 BC pretty accurately by using the JBM velocity BC calculator. I've compared those G7 BCs with bullets whose BCs were measured by AB's big Doppler and got values within 5% of what they measured over 1500 yds. G1BCs aren't accurate because they are too velocity dependent.

 

[hunter87]

Picked up some 205gr sbd2's for my 300 Norma. Did a ladder test while looking for pressure with h1000 from 81-86gr. could only shoot 500 yards because of rain making the fields so muddy. looked like a good node with a flat spot between 82–83gr only gained 16fps, about 1.8" vertical.got stiff bolt lift at 84gr. Loaded up a jump test with 82.5gr and went from .010 off to .070 off. .060 off printed a nice little group right around .4 of an inch at 100 yards, despite battling pretty bad mirage, with an ES of 4fps. Loaded up the same load today but wasn't able to shoot at distance just 100 yards and put 3 in almost the same hole with an ES of 3fps. Will have to wait until I can get some distance out it seems promising. Anyone else shoot these in a 300 Norma? Was kind of shocked to hit pressure so early but velocity seemed good

 

[nralifer]

Picked up some 205gr sbd2's for my 300 Norma. Did a ladder test while looking for pressure with h1000 from 81-86gr. could only shoot 500 yards because of rain making the fields so muddy. looked like a good node with a flat spot between 82–83gr only gained 16fps, about 1.8" vertical.got stiff bolt lift at 84gr. Loaded up a jump test with 82.5gr and went from .010 off to .070 off. .060 off printed a nice little group right around .4 of an inch at 100 yards, despite battling pretty bad mirage, with an ES of 4fps. Loaded up the same load today but wasn't able to shoot at distance just 100 yards and put 3 in almost the same hole with an ES of 3fps. Will have to wait until I can get some distance out it seems promising. Anyone else shoot these in a 300 Norma? Was kind of shocked to hit pressure so early but velocity seemed good

Yes, a friend of mine, Chad Stevens is shooting this bullet from a 300 Norma Improved using H50 BMG. He is getting around 3200 fps (30-32"barrel) and wants to use this bullet for light gun ELR competition. Despite the fact that it is a hunting bullet, the rapid expansion when it hits dirt might give it a larger splash than expected for a relatively small bullet.

Excellent data. What speed were you able to attain and how long is your barrel?

 

[Northkill]

Excellent data. What speed were you able to attain and how long is your barrel?

The speed is listed on the targets...

I got some comparative testing to demonstrate the effect of BC in the 308 Win (24" Bartlein, Lapua Palma SRP brass, 1x firing full length sized, CCI 450 primer).
Used a Lab Radar and measured the G7 BCs from the radar data.
Load was 49.5 gr Leverevolution with both bullets loaded 0.025"off lands.
Conditions 57F, 33% humidity, 28.25 inHg
Velocity, energy and BC calculations using JBM Trajectory and JBM BC (Velocities) calculators

Doing the same charge for differently designed bullets doesn't really show full potential vs full potential, but for strictly BC demonstration, the test works.

Your 150 gr gives the 308 Win some new reach. But more velocity will too.

 

[hunter87]

Yes, a friend of mine, Chad Stevens is shooting this bullet from a 300 Norma Improved using H50 BMG. He is getting around 3200 fps (30-32"barrel) and wants to use this bullet for light gun ELR competition. Despite the fact that it is a hunting bullet, the rapid expansion when it hits dirt might give it a larger splash than expected for a relatively small bullet.

Excellent data. What speed were you able to attain and how long is your barrel?

28" carbon 6 barrel, 3130fps

 

[nralifer]

The speed is listed on the targets...


Doing the same charge for differently designed bullets doesn't really show full potential vs full potential, but for strictly BC demonstration, the test works.

Your 150 gr gives the 308 Win some new reach.

You are right it doesn't show full potential, but the real purpose was to test the claim that lowering the contact surface between the barrel and the bullet by putting a bunch of ridges on the bullet reduces friction and improves muzzle velocity. If that was always the case then given the same gun , powder, charge, primer, brass, bullet jump and atmospheric conditions that the bullet with the smallest in contact bearing surface would be pushed faster. This test demonstrated just the opposite. ES was virtually the same meaning the velocity SDs were the same making the velocity difference significant in so far as the contact surface vs MV is concerned. Multiple ridges don't seem to necessarily improve MV by reducing internal barrel friction. There can be several other factors involved, not the least of which is the lubricity between the two metals, mainly the copper alloy used and the barrel steel. I fully expected the ridged bullet to be faster, the question was how much faster. As it turned out the BD-2 bullet was faster. I also knew there was a large BC difference between the bullets, but with actual on the same day side to side comparison, our BC was slightly larger than we advertise and theirs was smaller than advertised. The combination of a larger than expected BC difference and a lower MV at the same charge out of the same gun results in a very large difference in potential expansion at distance given what we have designed for our bullets as the minimum 1700 fps required for reliable expansion. That awaits low velocity expansion tests on our competitors bullets to see if their claims are verifiable. They could behave better than we expect, who knows. One thing is very obvious, and that is the large energy difference between similarly weighted bullets at 600 yds. Our bullet, by virtue of it's greater BC has 53% more energy retained at 600 yds because of the fact that kinetic energy is a product of bullet mass a 1/2 velocity squared.

 

[Northkill]

You are right it doesn't show full potential, but the real purpose was to test the claim that lowering the contact surface between the barrel and the bullet by putting a bunch of ridges on the bullet reduces friction and improves muzzle velocity. If that was always the case then given the same gun , powder, charge, primer, brass, bullet jump and atmospheric conditions that the bullet with the smallest in contact bearing surface would be pushed faster. This test demonstrated just the opposite. ES was virtually the same meaning the velocity SDs were the same making the velocity difference significant in so far as the contact surface vs MV is concerned. Multiple ridges don't seem to necessarily improve MV by reducing internal barrel friction. There can be several other factors involved, not the least of which is the lubricity between the two metals, mainly the copper alloy used and the barrel steel. I fully expected the ridged bullet to be faster, the question was how much faster. As it turned out the BD-2 bullet was faster. I also knew there was a large BC difference between the bullets, but with actual on the same day side to side comparison, our BC was slightly larger than we advertise and theirs was smaller than advertised. The combination of a larger than expected BC difference and a lower MV at the same charge out of the same gun results in a very large difference in potential expansion at distance given what we have designed for our bullets as the minimum 1700 fps required for reliable expansion. That awaits low velocity expansion tests on our competitors bullets to see if their claims are verifiable. They could behave better than we expect, who knows. One thing is very obvious, and that is the large energy difference between similarly weighted bullets at 600 yds. Our bullet, by virtue of it's greater BC has 53% more energy retained at 600 yds because of the fact that kinetic energy is a product of bullet mass a 1/2 velocity squared.

The lower contact surface does improve velocity potential. I've done enough to know that. Takes different powder and charges, but it does give a good bit more potential. I don't think you want to start that discussion here. I use your projos as well as others and have lots of experience in multiple rifles. I've milked them all to the fullest and know where the potential is.

 

[nralifer]

The lower contact surface does improve velocity potential. I've done enough to know that. Takes different powder and charges, but it does give a good bit more potential. I don't think you want to start that discussion here. I use your projos as well as others and have lots of experience in multiple rifles. I've milked them all to the fullest and know where the potential is.

So in your experience what 30 cal bullets have you tested and how to realize their potential. Maybe I was using the wrong experimental design.

 

[Maol]

Your results seem counterintuitive. They sure leave you scratching your head and wondering WTH? All else being equal, case, charge ,primer, jump etc. Less surface contact, less friction, correct? But it appears not.

Was engraving force the difference? Were the diameters exactly the same? Different alloys?

 

[Northkill]

I have no 30 cal. at this point. So far 6.5mm, .277, 7mm...

Same charge with two different bullets of the same weight resulting in two different velocities generally indicates the lower velocity bullet is at lower pressure. The lower engraving pressure bullet when pushed at the same pressure as the higher engraving pressure bullet will generally show more velocity.

 

[nralifer]

The results are what they are. I can't tell you why. I suspect it is a difference in alloys and a lesser lubricity (greater friction) between Bullet #1 and the barrel steel. Because of the difference in BCs, to attain the same energy at 600 yds as the BD-2 under the same conditions, Bullet #1 would have to be launched at 3600 fps. I doubt that can be done in a 308Win with a 24" barrel. Even so at 900 yds bullet energy for #1 is below that of the BD-2. See the JBM trajectory calculations for both bullets. The BD-2 is on the left picture (G7BC=0.266), and that of Bullet #1 is on the right (G7BC=0.184). It is very difficult to compensate for large BC differences with speed.