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Range Report Does A-max expand at low velocities?

MrSwede

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Jun 5, 2009
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According to Hornady, A-max needs 2000fps+ to expand.
Atleast thats what they reccomend. I've heard they expand well below 2000fps, but never how low. 1800fps? 1600fps? 1400fps?

Anyone have any experience to share?
 
Re: Does A-max expand at low velocities?

Yes. It is very difficult to design a hunting bullet that will work at all velocities, both low and high.

If a bullet expands well in a game animal @ 1800 FPS, what to you think it will do @ 2800 FPS or faster? It will most likely blow up.

That's why bullets designed to expand at low velocities, like pistol bullets or rifle bullets designed for say the 45-70, have wide flat noses, or large hollow points or the like. Not good for LR shooting.

Bullets like the A-Max do work over a large velocity range. But expansion below 2000 FPS, will depend more on what it hits.

Punch through deer's chest at long range (after droping below 2000 FPS) with an A-Max,and miss rib bone, and likely little to no expansion. Hit some bone, and likely you get expansion.

Punch a deer through his heart, spine, liver, or both lungs and out the other side, and it matters little if the exit hole is 35 cal or 30 cal. You will eat venison.

In summary sometimes you will get expansion below 2000 FPS, and sometimes you won't. Hit the animal right, it won't matter, hit poorly, and all the expansion in the world will not help.

I should also note that a 208 Gr A-Max @ 1800 FPS impact will do more damage and penetrate further, than a 155 gr A-Max for example, going a bit faster.

Sectional Density and Ballistic Coefficients are not just a clever numbers. They have real meaning relating to penetration and bullet performance at long range.

It's easy to get seduced by velocity. But velocity is a wasting asset; SD and BC are forever.....

Bob
 
Re: Does A-max expand at low velocities?



Thank you for a good and well formulated reply!

More replies greatly appreciated guys.
 
Re: Does A-max expand at low velocities?

i hit a coyote at 288 yards (directly facing me) with a 168gr A-Max and didnt exit. made me think twice about using it on a deer.
 
Re: Does A-max expand at low velocities?

the 224 75 gr amax expanded well @ 1000 fps , when they hit a sand bank . not sure on a deer @ that dist
wink.gif
 
Re: Does A-max expand at low velocities?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BobinNC</div><div class="ubbcode-body">Yes. It is very difficult to design a hunting bullet that will work at all velocities, both low and high.

If a bullet expands well in a game animal @ 1800 FPS, what to you think it will do @ 2800 FPS or faster? It will most likely blow up.

That's why bullets designed to expand at low velocities, like pistol bullets or rifle bullets designed for say the 45-70, have wide flat noses, or large hollow points or the like. Not good for LR shooting.

Bullets like the A-Max do work over a large velocity range. But expansion below 2000 FPS, will depend more on what it hits.

Punch through deer's chest at long range (after droping below 2000 FPS) with an A-Max,and miss rib bone, and likely little to no expansion. Hit some bone, and likely you get expansion.

Punch a deer through his heart, spine, liver, or both lungs and out the other side, and it matters little if the exit hole is 35 cal or 30 cal. You will eat venison.

In summary sometimes you will get expansion below 2000 FPS, and sometimes you won't. Hit the animal right, it won't matter, hit poorly, and all the expansion in the world will not help.

I should also note that a 208 Gr A-Max @ 1800 FPS impact will do more damage and penetrate further, than a 155 gr A-Max for example, going a bit faster.

Sectional Density and Ballistic Coefficients are not just a clever numbers. They have real meaning relating to penetration and bullet performance at long range.

It's easy to get seduced by velocity. But velocity is a wasting asset; SD and BC are forever.....

Bob
</div></div>
Bob how does SD actually affect terminal ballistics? I read this article and still can't seem to get a grasp on it.
http://www.gsgroup.co.za/articlesd.html
 
Re: Does A-max expand at low velocities?

Sectional density is a bullet's weight in pounds divided by the square of its diameter in inches. It plays an important role in bullet penetration. Bullets with greater sectional density tend to penetrate deeper.

As a rule-of-thumb guideline, sectional density can be used estimate and compare penetration performance. Bullets of similar sectional densities, propelled at similar velocities, and exhibiting similar percentages of expansion tend to penetrate to similar depths.

Since Sectional Density is computed using bullet weight and bullet diameter, so as SD goes up so does the potential Ballistic Coefficient.

For example:

Berger Cal 308 Target Bullets

SD = Sectional Density:

155.5 gr SD 0.234 G1 BC 0.464 G7 BC 0.237

175 Gr VLD SD 0.264 G1 0.498 G7 0.255

190 Gr VLD SD 0.286 G1 0.570 G2 0.291

210 gr VLD SD 0.316 G1 0.631 G7 0.323

The article you noted is by GS Custom a South African bullet maker. Their bullets are much like Barnes X in that they use no lead. Hence their SD's are poor, but their bullet construction is sound, therefore they are asking that you ignore SD due to their bullets unique construction.

And they may be right for homoginous bullets, but for a standard cup and core bullet (lead and guilding metal) SD does have meaning, and it relates to it's terminal performance (penetration).

Bob
 
Re: Does A-max expand at low velocities?

i used a 168amax .308 at 2780fps
at 200y no expansion on a head shot [small deer]
small exit hole no signs of expansion at all.

second shot 100y heart shot, again no expansion

both were done as tests back up rifle there as well, just wanted to see if they worked, keeping them for targets now
 
Re: Does A-max expand at low velocities?

75gr .224" amax still expands nicely in a rabbit at 1500fps. Noticably less than at higher speeds obviously.
 
Re: Does A-max expand at low velocities?

Could someebody chime in on how twist rate may affect expansion and complete bullit distruction ?
 
Re: Does A-max expand at low velocities?

I've always wanted to develop reduced loads and do ballistic gel testing of bullets and see how low the velocities can go before expansion becomes erratic, or non-existent. I figured it work great developing loads like you would for a suppressed rifle, and work the velocities up from subsonic to see what the results were.

It would be nice if manufactures provided this data on a more consistent basis to provide us with a number that we would know as a maximum effective range to engage a target at.

Branden
 
Re: Does A-max expand at low velocities?

Here's my limited experience with the 208 amax hunting wise...

I just came back from a 10 day float hunt. Used my .30-06 208 amax load going 2700fps at the muzzle:
Shot two caribou, 1st was at 512 yards Through the shoulder. Shoulder joint was a mess of bone fragments, Bullet was intact and mushroomed on the opposite side when I found it, but when I pulled it out it separated from the jacket. caribou went down and didn't get up. Bou was dying, still moving his head a little, second shot put it down for good. (Don't know if the recovered bullet was the first or second shot, only recovered one bullet) Velocity at that distance predicted at 2014fps.

2nd caribou at 300yards, went through the shoulder blade and blew out a rib on the opposite side. Internal damage was extensive. Bou ran 10 yards and flipped over.


 
Re: Does A-max expand at low velocities?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MrSwede</div><div class="ubbcode-body">

According to Hornady, A-max needs 2000fps+ to expand.
At least thats what they recommend.</div></div>

Just wondering where you got that info. My data says 1600 fps minimum.