Heavy Bullets!

[RMulhern]

Here's an observation:

Take two objects; a locomotive engine and a light Volkswagen. Put a set of wheels on the Volks akin to the locomotive engine and set the Volks on a set of tracks akin to the locomotive so as to have the same moment of friction. Accelerate both to 60 miles per hour, put both in neutral to coast and which do you think will coast further down the track?

Me thinks it's MOMENT & INERTIA!

 

[blipelt]

You are correct but you forgot about the spinning of the object. Sit in a chair and spin and then spin faster, which one will take more energy to move you?


I have another question then:

A mentor(very credible source) visited with me about five+ years ago about this and I haven't read anything about it since. Granted I learn on the range more than I read. He figured a fast twist barrel would cause less wind drift than a standard twist barrel. His gunsmith, Dan Dowling proved it using the example. Ex. a 6br in 14 twist and 8 twist with 58gr vmax same velocity. The 8 had less wind drift and when it hit a pdog all you could find was a leg. Kind of why I always run a little faster twist than the bullet I plan on trying to use.


Anyone ever read or have any experience with this?

Brent

 

[blipelt]

Another question:

If it is all about weight and BC. Then why is the itty bitty 6Dasher kicking the crap out of the bigger calibers in 600 and 1000yd. benchrest. Last time I checked it won light gun, Heavy gun, and F-class in Calif during the NBRSA Nationals.


Brent

 

[Scot E]

Scott, I hear what you are saying but lets not forget the OP article was done at only 1000 yards and supported this. This was preformed by two respected long range competative shooters. I agree it becomes more prevelant at longer distances (everything does) and the shortest I did the test was 1000 yards. I ask no one to take my word for it. I would suggest if the article is not sufficent proof then by all means get with a buddy and do the test for your self. You may be surprised.

As far are the programs windage info being correct? That is hard to tell as we perfect the drops( elevation) with BC and velocity tweeking to get them perfect. Again elevation is something we can get spot on. But windage / wind drift is not as we have no way I know of to prove what actual winds the bullet is actually traveling in. So with what I have to work with I can't call a program right or wrong. But, like I have done, we can prove which bullet does indeed have the most drift simply by shooting them back to back in like conditions. And the more samples the better.

One thing this has proven to me is to look at what is in front of you. Not what someone says. The small fast bullet coolaid does not taste good to me. Now a heavy fast bullet,... well that has a very appealing flavor. I have some of that brewing as we speak.

Jeff

Ya, I am awful anxious to see what Shawn comes up with for your LRKM. It really sounds like the very best LR scenario! 338, the best brass, a fantastic platform, and his new throat design. Man, my mouth is watering right now!

Here is an example of what I am talking about. This data is for a light weight carry gun that my kids use/used when they were young and is still one of my favorite carry guns. It is a 30'06 weighing about 9.5 lbs.

View attachment 3006.bmp

As you can see the terminal velocity of the heavy for caliber 210 VLD only gets me to about 500 yards before I don't have enough velocity for consistent expansion. But with the lighter 168 VLD I can go out to 650 yards. Out to that distance the drop is much less and the drift is so close it isn't a factor in determining what to use.

This is in no way meant to prove my case in absolute, but it is just an example of a real world scenario where the heavy, high BC bullets don't make as much sense as a lighter mid weight bullet, at least for me. I get less recoil as well which in this gun allows me to shoot it a bit better and also allows me to stay on target a bit better after the shoot is executed.

I have a similar scenario with a 6.5 that shoots the 130 high BC bullets quite a bit faster than the 140's and provides a better ballistics down range as well.

I guess my point is similar to yours, everyone needs to shoot their gun with their loads to see how things are going to play out. I trust my ballistic programs more than you do that is clear. But I imagine much of that is due to the fact that I shoot mostly under 1000 yards and I think Ballistic programs are much more accurate there compared to where you shoot.

Thanks for your input here.

Scot E.

 

[Broz]

Thanks Scott and I see your point. I had not even considered the 500 yard shot as the article was about long range bullets. I agree, if you are only shooting to 500 or 600 yards then that is completely different. Your info proves in some bore sizes like a .308 there are bullets that would go too heavy for the caliber. But don't ask Montana Marine about his 30-06. I have seen it go way out there on rocks well past 1000 and a few weeks ago we were shooting clay pigeons with it at 1010 yards with it. He loads it with 208 gr bullets.

If I was to shoot the very low expanding bullets some do I would want all the velocity I could get too. Terminal performance is a whole other thread. I was strictly talkig wind drift here.

Jeff

 

[Broz]

Another question:

If it is all about weight and BC. Then why is the itty bitty 6Dasher kicking the crap out of the bigger calibers in 600 and 1000yd. benchrest. Last time I checked it won light gun, Heavy gun, and F-class in Calif during the NBRSA Nationals.


Brent

Bret, I do not follow these matches, but are they shooting 60 ~ 70 gr bullets in them or 105 to 115 gr?

Jeff

 

[Joe King]

You are correct but you forgot about the spinning of the object. Sit in a chair and spin and then spin faster, which one will take more energy to move you?


I have another question then:

A mentor(very credible source) visited with me about five+ years ago about this and I haven't read anything about it since. Granted I learn on the range more than I read. He figured a fast twist barrel would cause less wind drift than a standard twist barrel. His gunsmith, Dan Dowling proved it using the example. Ex. a 6br in 14 twist and 8 twist with 58gr vmax same velocity. The 8 had less wind drift and when it hit a pdog all you could find was a leg. Kind of why I always run a little faster twist than the bullet I plan on trying to use.


Anyone ever read or have any experience with this?

Brent

did he have spin drift figured into this? I know it's effect can be small shooting in 1 direction with wind coming from a given angle , but reverse that wind direction and it can shift POI several inches at 1k

 

[blipelt]

Typically they shoot 105 to 107's and some are using the heavier 115's. I wasn't a fan until I started looking at it more.

My load is 33.2grs. of RL15 450primers and 105 berger Hybrids(2960fps). Took third in my first match last weekend. Only had a couple days to work up a load and get familar with the new rifle.

Joe, I can't say for sure. second hand information.


Brent

 

[Long Time Long Ranger]

The analogies I read with light vs heavy have nothing to do with bullet flight and are irrelavent.

Again, the highest BC will win no matter what the weight. Two bullets with the same bc will be equal no matter what the weight.

Again, the bc equation takes into consideration bullet flight dynamics and weight. That is why a 100 grain bullet can easily fly better with less wind drift and a higher retained velocity at long range than a 300 grain bullet. Just depends on the BC of each.

 

[WildRose]

Ya, I am awful anxious to see what Shawn comes up with for your LRKM. It really sounds like the very best LR scenario! 338, the best brass, a fantastic platform, and his new throat design. Man, my mouth is watering right now!

Here is an example of what I am talking about. This data is for a light weight carry gun that my kids use/used when they were young and is still one of my favorite carry guns. It is a 30'06 weighing about 9.5 lbs.

View attachment 10541

As you can see the terminal velocity of the heavy for caliber 210 VLD only gets me to about 500 yards before I don't have enough velocity for consistent expansion. But with the lighter 168 VLD I can go out to 650 yards. Out to that distance the drop is much less and the drift is so close it isn't a factor in determining what to use.

This is in no way meant to prove my case in absolute, but it is just an example of a real world scenario where the heavy, high BC bullets don't make as much sense as a lighter mid weight bullet, at least for me. I get less recoil as well which in this gun allows me to shoot it a bit better and also allows me to stay on target a bit better after the shoot is executed.

I have a similar scenario with a 6.5 that shoots the 130 high BC bullets quite a bit faster than the 140's and provides a better ballistics down range as well.

I guess my point is similar to yours, everyone needs to shoot their gun with their loads to see how things are going to play out. I trust my ballistic programs more than you do that is clear. But I imagine much of that is due to the fact that I shoot mostly under 1000 yards and I think Ballistic programs are much more accurate there compared to where you shoot.

Thanks for your input here.

Scot E.

This is a case similar to one we discussed recently. In the case of the 30-06 using such a heavy bullet makes far less sense since you lack the case capacity to launch it at an MV capable of maximizing the higher BC of the heavier bullet.

Work your same numbers but speed it up 400fps and see how much better the heavy bullet performs.

 

[Truc]

Another question:

If it is all about weight and BC. Then why is the itty bitty 6Dasher kicking the crap out of the bigger calibers in 600 and 1000yd. benchrest. Last time I checked it won light gun, Heavy gun, and F-class in Calif during the NBRSA Nationals.


Brent

I shot a 6 dasher for a while at 600 yd IBS matches and I think the reason this cartridge does so well is ease of shooting or lack of recoil, and its an accurate round. I shot mostly Euber 108's as they were easy to tune. The down fall was they were a Boat tail and not a VLD. The Berger 105's with the same load had less drop and pushed less in the wind. So a lighter bullet w/ a better BC out shot the heavier lower BC bullet. now saying this the Euber shot some consistant groups just not always in the X ring

 

[Franklin]

The analogies I read with light vs heavy have nothing to do with bullet flight and are irrelavent.

Again, the highest BC will win no matter what the weight. Two bullets with the same bc will be equal no matter what the weight.

Again, the bc equation takes into consideration bullet flight dynamics and weight. That is why a 100 grain bullet can easily fly better with less wind drift and a higher retained velocity at long range than a 300 grain bullet. Just depends on the BC of each.

Go ahead and take the best bc 6mm, 100gr bullet and the best bc 338, 300gr bullet and shoot them at identical velocity's...say 2800fps and let us know what fly's better with less wind drift and higher retained velocity. I know what your thinking...they don't make a 6mm bullet with the same bc.(that I know of) So why, do you make such a stupid statement? I'll promise you that weight has more to do with flight than what you give it credit for. Time to put the ballistic programs down and do some real testing.

 

[blipelt]

Truc, did you get rid of dasher? Did you ever hear of anyone else trying the fast twist vs slower twist for wind drift?



Brent

 

[WildRose]

The analogies I read with light vs heavy have nothing to do with bullet flight and are irrelavent.

Again, the highest BC will win no matter what the weight. Two bullets with the same bc will be equal no matter what the weight.

Again, the bc equation takes into consideration bullet flight dynamics and weight. That is why a 100 grain bullet can easily fly better with less wind drift and a higher retained velocity at long range than a 300 grain bullet. Just depends on the BC of each.

Actually I just ran six different comparisons with imaginary bullets comparing 6.5 140gr BC .520 to .308 180gr starting with the same BC's Same velocity of 3000fps. I kept lowering the BC of the .308 all the way down to .420 and the heavier bullet still showed less wind drift (20mph wind) all the way down until I hit the .420 BC.

It takes either more force or the same force acting longer to move a heavier object vs the lighter object.

Weight is definitely part of the equation when it comes to wind drift and it seems at least after a few preliminary runs on the ballistic calculator to weight considerably more in the equation than does BC.