Is there actually any downrange advantage for very heavy for caliber bullets?

[sambo3006]

I've been seeing some extremely heavy for caliber rebated boat tail bullets being introduced by smaller bullet makers. These bullets all seem to have very long bearing surfaces. I would think that this would not only reduce ballistic coefficient significantly, but also possibly reduce velocity potential. I'm skeptical of one of these bullets having superior downrange trajectory, wind drift, and retained energy when compared to somewhat lighter VLD profile bullets with shorter bearing surfaces and longer, more streamlined ogives (when both are driven to top velocity potential). Anyone with some experience with these bullets, feel free to chime in. Thanks!
Sam

 

[The_Whitetail_kid]

I think it depends on the type of bullet but on a bullet designed to fragment (Berger) I think heavy for caliber is best because if the bullet is going extremely fast like the light for caliber bullets, you have a higher chance of a bullet blowing up and not penetrating. Berger even told me optimal speeds for their bullets as far as game performance go are 2800-2900. I've killed/seen animals killed with light for caliber bergers and heavy for caliber bergers and while I personally haven't had one blow up the heavy for caliber are definitely more devastating.

 

[MagnumManiac]

Simple fact here is that longer heavier bullets normally have higher BC. This is what justifies these bullets. If you have the twist fast enough to stabilise a heavier bullet, then those lesser weighted bullets won't catch up to a point where velocity is too low, but the energy increase may just be the turning point.
I have always been heavy bullet for calibre guy, but there is a real and fast rule I stick to, which is, the cartridge MUST be able to deliver 2800fps minimum with the chosen bullet and, I prefer 3000fps if I can get it. If I am designing a case, such as my wildcats based on the 416 Rigby Improved, I look for the maximum weight that will get a minimum of 3200fps, more is often achieved which is how I like it to go.

Cheers.

 

[FEENIX]

I've been seeing some extremely heavy for caliber rebated boat tail bullets being introduced by smaller bullet makers. These bullets all seem to have very long bearing surfaces. I would think that this would not only reduce ballistic coefficient significantly, but also possibly reduce velocity potential. I'm skeptical of one of these bullets having superior downrange trajectory, wind drift, and retained energy when compared to somewhat lighter VLD profile bullets with shorter bearing surfaces and longer, more streamlined ogives (when both are driven to top velocity potential). Anyone with some experience with these bullets, feel free to chime in. Thanks!
Sam

For me, yes! Below is a 145 Black Hole out my .257 WBY with 22" barrel.

I do not have the BC yet, but during my pressure test, I am propelling the 163 Chinchaga at 2915 FPS using H1000. I have some loaded with Retumbo on my next range opportunity.

 

[tim_w]

This can be easily answered by running the numbers thru a ballistic calculator. Hope on jbm as its online. You can then run the vel and see where the cross over point is. Also for me wind deviation is much more critical to me then vert drop. Minimum vel is a matter of bullet construction performance window and energy. Despite what I have seen some posts on forums insinuate, terminal energy matters.

 

[keith4kk]

I agree. We reload most all our hunting rounds. 3 of us shoot 300WM often and out to 1060 yards. I shoot 190 VLDs, Jason shoots 200 Fed ascent, my son shoots 212 eldx. Line the ballistics up side by side. All great preforming, good BC. Very sumilar MV about 2900 to 3000 on all 3. The 212 has more energy and velo even out.at 1000 with less drop. They all hit like a train on an animal or steel. Inertia

 

[DUCKMAN11]

The pull on a bullet by earth's gravity is a known and constant number and can be accounted for. However it's hard to judge a cross wind speed and true direction especially at distance. BC fights both of those. A higher BC bullet has less wind drift and terminal energy and velocity should stay better longer.

That being said bullet construction and impact speed go hand in hand.

There is such a thing as too much of a good thing also. I don't think a 215gr bullet in a 7mm or a 160gr bullet in a 257cal would be worth the effort just because you couldn't drive them fast enough to out perform something lighter.

 

[keith4kk]

You are correct. I think each caliber has its range of usable weight grain per type and purpose. A 7mm isn't going to run as heavy as a 300. Depending on shape and barrel twist. Plus just finding the projectile and load the meets your purpose and works best with your setup.

 

[MagnumManiac]

Despite what I have seen some posts on forums insinuate, terminal energy matters.

My point regarding energy is in fact aimed at pointing out what is going to have a higher momentum and hold its velocity further.
I actually do not look at energy for the reason of killing power.

Cheers.

 

[civy93]

build yourself two ballistic profiles. One using heavy sleek bullets, and one using lighter less sleek bullets that are going a bit faster. (If you can plug in your numbers or off the box numbers, it will give you a general idea of the gain) You can tell eventually where the slightly slower more aerodynamic bullet takes over both vertically (drop) and horizontally (wind deflection). It's actually pretty fun (I'm a nerd). If you only shoot (generally) 300 yards and in, it may not be as big of a gain for you.

 

[wilehunting]

I've always used mid weight bullets for caliber. Generally, 165gr Sierra btsp game kings in the factory Federal loading for 308Win. Although I am interested in this post. My opinion has been that when, looking at the heavier bullets for caliber, you trade velocity for higher bullet weight. I would like to know how a high bc copper solid expanding hunting bullet compares to a lead/copper of similar weight. Best of both worlds?

 

[1mechanic]

The copper solids of the same weight will be much longer than copper lead bullets and will require a much faster twist for their length.

 

[Phil Rizzo]

With extreme bullet weight for caliber, fast twist rifling is more important obviously for general stabilization. And a high enough SG number to maintain your bullets BC at distance.
The faster the twist, the more resistance you fight to obtain velocity.
There is always a balance, and Berger's calculator is Golden when it comes to finding the sweet spot. Heavier is not always better, and unless you have the horsepower to ship them out, may actually be a detriment.
If the gun prefers one side or the other of "ideal" that counts, too, concerning precision.

 

[wilehunting]

The copper solids of the same weight will be much longer than copper lead bullets and will require a much faster twist for their length.

I think my 308 would have a 1:10 twist. 1mechanic, you think I would need a faster twist to use a 165 copper solid with high bc over a 165 lead/copper?

I'm new to all this faster twist stuff. The rifle twist rate has always been whatever the factory made it.