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Light vs Heavy bullets with similar BC\'s
With a high percentage of my rounds being fired only to punch paper or clang steel I'm primarily interested in decreasing the effects of distance and wind. That being said, I also hunt small and large game animals and I'm beginning to wonder if there is any need/advantange to using a heavier bullet over a light bullet given that both have the approx same BC. Keep in mind that I'm talking about non-dangerous (inherently) game.
This train of thought arose just recently when I came across a series of high (relative) BC bullets. For example, I can launch a .5 155 grain 30 caliber bullet at 2850fps or I can opt for a .5 175 grain bullet at 2650fps. The lighter bullet has a speed advantange with the same BC so I benefit by having less elevation and wind adjustment to deal with for the entire effective range of the two compared bullets.
Also, I'm looking at being able to use a bullet with a still higher BC (.6 range) and am considering using once again a lighter bullet with higher speed to decrease the elevation and wind variables.
Discussion:
What am I loosing by going for the higher BC lighter faster bullet over the heavier similar BC bullet? (Keep in mind that I'm not going to change to another cartridge/rifle, 308 Winchester is the only option.)
posted April 26, 2001 06:34 AM
Warren Jensen
Member
From: Arco, ID US
Registered: April 12, 2001
Posts: 12
Light vs Heavy Bullets
--------------------------------------------------------------------------------
Dave,
I don't need to expound on how to compare the bullets ballistically as you have the background to do this.
For perfomance on game the way to differentiate is to test them. One of the simplest ways is to used well soaked newspaper or magazines and shoot the bullets into them at the ranges you expect to be shooting game. High impact velocities tear bullets up and greatly reduce their lethality. You have to shoot the paper at the longer ranges as simply downloading to a calculated velocity will not accurately show the stability and penetration characteristics. I can go into great detail on what will constitute lethal criteria, but let's make it simple. Forget weight retention and mushroom. Look at the wound channel. If the wound channel is fist sized or larger and maintains that diameter for six to ten inches, and the total penetration is twelve inches or more then you have a lethal round. Look for a wider longer channel if you are hunting bigger game. On very long shots where the bullet is traveling less than 1500 fps when impacting, then there will be no secondary to speak of, but the bullet should make a hole bigger than one caliber. If it does then it will be doing as well as can be expected at those ranges. If you are hunting animals with heavy bones, place the greenest pine boards you can find in the media two to four inches into the stack. Place them at angles so that the bullet has to penetrate obliquely. Again, wound channel is what kills, so evaluate the bullets on the hole that they make.
These tests will give you the information you need to make your decision.
[email protected] http://www.lostriverballistic.com
posted April 26, 2001 08:21 AM
Dave King
Moderator
From: Damascus, MD
Registered: April 11, 2001
Posts: 16
Warren
Thanks for the reply.
I'll use the wet newspaper/magazine test and the 'green' pine boards is an added feature I've never heard of but it sounds like a good test medium.
I'm going to a Long Range class this weekend (Fri - Sun) and may build a light plastic container of the wet newspaper/magazine/pine board medium for a series of range tests.
Thanks
posted April 26, 2001 09:22 AM
David P. Herne
Member
From: Houston, Texas (USA)
Registered: April 11, 2001
Posts: 13
Relative lethality of bullets
--------------------------------------------------------------------------------
Dave,
**** good inquiry!
Warren,
I've never seen a bullet in any reasonable hunting caliber tear a fist-size wound in any kind of game! But then I've never shot or seen anything shot with anything other than Match HPBTs, Nosler Ballistic Tips, or generic soft nose hunting type bullets (e.g. Nosler partitions).
Will your L.R.B.T. bullets do this?
Dave
N/A
posted April 27, 2001 10:18 AM
Warren Jensen
Member
From: Arco, ID US
Registered: April 12, 2001
Posts: 12
Fist sized hole.
--------------------------------------------------------------------------------
David,
"Fist sized hole" includes the secondary wound channel(that is the tissue out side the primary hole that has been compressed and damaged).
I can document many instances where the hole in the entry chest wall of an elk is four inches across, with the lung tissue of both lungs being pulverized into a mass with no chunks bigger than the size of your thumbnail. The exit chest wall holes were greater than two inches across. The first time I saw this was in 1988 from a 30-06, & 165 gr. bullet at a range of 185 yds. ( It was one of my bullets, naturally).
When impact velocities are below 2500 fps. the secondary begins to shrink until it doe not exist at impact velocities of 1500 fps. and less. At impact velocities above 3400 fps. it grows dramatically, but the bullet has to hold together. Most don't. At 4000 fps. we have to markedly limit the expansion frontal area or we end up with an animal that is bloodshot from the tip of it's nose to the tip of it's tail. I have seen an antelope in this condition. There wasn't five lbs. of edible meat left on it. At 4500 fps. we reach a point where the bullet does not have to expand at all. We have been up to 5300 fps., and I do not think anything bigger than .257 cal. will be needed at these velocities for game in North America. (You won't be able to buy these things for a while. The materials have to be improved a bunch. Most guys like to get more than 15 rounds through their barrels before they have to get a new one.)
[email protected] http://www.lostriverballistic.com
posted April 27, 2001 11:10 AM
David P. Herne
Member
From: Houston, Texas (USA)
Registered: April 11, 2001
Posts: 13
Bullet performance at varying velocities
--------------------------------------------------------------------------------
Warren,
I gather from what you're saying that for hunting purposes the best results in a bullet are seen at velocities of between 2900 and 3400 fps - assuming that the bullet retains the bulk of its mass, that is.
Hell, this being the case, the 7mm Dakota is exactly what I'm looking for! It shoots your 162-grain hunting bullet to velocities of around 3200 fps!
Regards,
Dave
N/A
posted April 28, 2001 03:23 PM
With a high percentage of my rounds being fired only to punch paper or clang steel I'm primarily interested in decreasing the effects of distance and wind. That being said, I also hunt small and large game animals and I'm beginning to wonder if there is any need/advantange to using a heavier bullet over a light bullet given that both have the approx same BC. Keep in mind that I'm talking about non-dangerous (inherently) game.
This train of thought arose just recently when I came across a series of high (relative) BC bullets. For example, I can launch a .5 155 grain 30 caliber bullet at 2850fps or I can opt for a .5 175 grain bullet at 2650fps. The lighter bullet has a speed advantange with the same BC so I benefit by having less elevation and wind adjustment to deal with for the entire effective range of the two compared bullets.
Also, I'm looking at being able to use a bullet with a still higher BC (.6 range) and am considering using once again a lighter bullet with higher speed to decrease the elevation and wind variables.
Discussion:
What am I loosing by going for the higher BC lighter faster bullet over the heavier similar BC bullet? (Keep in mind that I'm not going to change to another cartridge/rifle, 308 Winchester is the only option.)
posted April 26, 2001 06:34 AM
Warren Jensen
Member
From: Arco, ID US
Registered: April 12, 2001
Posts: 12
Light vs Heavy Bullets
--------------------------------------------------------------------------------
Dave,
I don't need to expound on how to compare the bullets ballistically as you have the background to do this.
For perfomance on game the way to differentiate is to test them. One of the simplest ways is to used well soaked newspaper or magazines and shoot the bullets into them at the ranges you expect to be shooting game. High impact velocities tear bullets up and greatly reduce their lethality. You have to shoot the paper at the longer ranges as simply downloading to a calculated velocity will not accurately show the stability and penetration characteristics. I can go into great detail on what will constitute lethal criteria, but let's make it simple. Forget weight retention and mushroom. Look at the wound channel. If the wound channel is fist sized or larger and maintains that diameter for six to ten inches, and the total penetration is twelve inches or more then you have a lethal round. Look for a wider longer channel if you are hunting bigger game. On very long shots where the bullet is traveling less than 1500 fps when impacting, then there will be no secondary to speak of, but the bullet should make a hole bigger than one caliber. If it does then it will be doing as well as can be expected at those ranges. If you are hunting animals with heavy bones, place the greenest pine boards you can find in the media two to four inches into the stack. Place them at angles so that the bullet has to penetrate obliquely. Again, wound channel is what kills, so evaluate the bullets on the hole that they make.
These tests will give you the information you need to make your decision.
[email protected] http://www.lostriverballistic.com
posted April 26, 2001 08:21 AM
Dave King
Moderator
From: Damascus, MD
Registered: April 11, 2001
Posts: 16
Warren
Thanks for the reply.
I'll use the wet newspaper/magazine test and the 'green' pine boards is an added feature I've never heard of but it sounds like a good test medium.
I'm going to a Long Range class this weekend (Fri - Sun) and may build a light plastic container of the wet newspaper/magazine/pine board medium for a series of range tests.
Thanks
posted April 26, 2001 09:22 AM
David P. Herne
Member
From: Houston, Texas (USA)
Registered: April 11, 2001
Posts: 13
Relative lethality of bullets
--------------------------------------------------------------------------------
Dave,
**** good inquiry!
Warren,
I've never seen a bullet in any reasonable hunting caliber tear a fist-size wound in any kind of game! But then I've never shot or seen anything shot with anything other than Match HPBTs, Nosler Ballistic Tips, or generic soft nose hunting type bullets (e.g. Nosler partitions).
Will your L.R.B.T. bullets do this?
Dave
N/A
posted April 27, 2001 10:18 AM
Warren Jensen
Member
From: Arco, ID US
Registered: April 12, 2001
Posts: 12
Fist sized hole.
--------------------------------------------------------------------------------
David,
"Fist sized hole" includes the secondary wound channel(that is the tissue out side the primary hole that has been compressed and damaged).
I can document many instances where the hole in the entry chest wall of an elk is four inches across, with the lung tissue of both lungs being pulverized into a mass with no chunks bigger than the size of your thumbnail. The exit chest wall holes were greater than two inches across. The first time I saw this was in 1988 from a 30-06, & 165 gr. bullet at a range of 185 yds. ( It was one of my bullets, naturally).
When impact velocities are below 2500 fps. the secondary begins to shrink until it doe not exist at impact velocities of 1500 fps. and less. At impact velocities above 3400 fps. it grows dramatically, but the bullet has to hold together. Most don't. At 4000 fps. we have to markedly limit the expansion frontal area or we end up with an animal that is bloodshot from the tip of it's nose to the tip of it's tail. I have seen an antelope in this condition. There wasn't five lbs. of edible meat left on it. At 4500 fps. we reach a point where the bullet does not have to expand at all. We have been up to 5300 fps., and I do not think anything bigger than .257 cal. will be needed at these velocities for game in North America. (You won't be able to buy these things for a while. The materials have to be improved a bunch. Most guys like to get more than 15 rounds through their barrels before they have to get a new one.)
[email protected] http://www.lostriverballistic.com
posted April 27, 2001 11:10 AM
David P. Herne
Member
From: Houston, Texas (USA)
Registered: April 11, 2001
Posts: 13
Bullet performance at varying velocities
--------------------------------------------------------------------------------
Warren,
I gather from what you're saying that for hunting purposes the best results in a bullet are seen at velocities of between 2900 and 3400 fps - assuming that the bullet retains the bulk of its mass, that is.
Hell, this being the case, the 7mm Dakota is exactly what I'm looking for! It shoots your 162-grain hunting bullet to velocities of around 3200 fps!
Regards,
Dave
N/A
posted April 28, 2001 03:23 PM
