Why did these 300 Win Mag rounds not disintegrate on impact?

[Onewolf]

Rifle newbie here.

These photos were posted on another (non shooting) forum and I never got an answer to my question. There were 308 and 300 Win Mag rounds fired at a distance of 600yds. The 308 rounds disintegrated on impact (as expected). The 300 Win Mag rounds penetrated and remained relatively intact. I am curious why a bullet would remain intact like that rather than disintegrating on impact (even if it penetrated some distance)?

Thanks.

 

[john_bud]

Too many factors to know from a picture. What bullets were shot? What ballistics from the loadings? etc...

The higher velocity of the 300 could have simply over powered the mild steel target

 

[DM~]

Two different bullets, with two different jacket materials or designs... A bullet can be designed to break up easily or not, it all depends on what the maker wants.

Yes, the 300 mags are faster, but that's why the maker of the "bullets", toughen them up to take the added velocity...

Like was said, really not enough info given to know the answer...

Chronographing both rounds to get the velocities, then disecting a bullet from each would tell the story!

DM

 

[MtnCreek]

Those 300wm bullets are probably solid copper. A 190 smk or 208 amax comes unglued on steel at 600 yds.

 

[627PCFan]

Id say a combination of a tough bullet, mild steel and just the right velocity to "catch" the bullet

 

[Walkalong]

The ears are a nice touch, but yea, it looks like some soft steel someone cut a silhouette from.

Either the .300 Mag had that much more energy left at 600 yards (Haven't looked at any charts), or it was a copper bullet, or both, and mild steel. IMO.

 

[Onewolf]

I got more info from the shooter.

The 300 Win Mag was shooting Federal Fusion 180 rounds. The 308 was shooting Federal Match 168 BTHP.

Federal Fusion 180

This specialized deer bullet electrochemically joins pure copper to an extreme pressure-formed core to ensure optimum performance. The result is high terminal energy on impact that radiates lethal shock throughout the target.

 

[The_Next_Generation]

There's your answer

The "BTHP" means boat-tail-hollow-point. These rounds are designed more for accuracy than sticking-together like a hunting round would be. I am sure the hollow-point only serves to aid in the resultant shredding of the projectile on steel. Also, the jacket of the BTHP ammo is probably thinner than the Fusion hunting-oriented round. I think this is so the bullet has a higher sectional-density (basically its heaver for its size and has a higher ballistic coefficient, I think..).

The reason the 300 WM didn't disintegrate is because the Fusion ammo is hunting-oriented. It is built to hold together for deep penetration of big-game, this is most-likely a result of a thicker jacket. The soft point helps the bullet to expand (aka "mushroom") but not disintegrate like in the case of the hollow-point. Again, when you are hunting, you want the round to stick together and expand.

I am not an expert by any means, but I think this should shed some light on your question. Maybe someone else can add to what I said

-TNG

EDIT: I just saw the description of the Fusion bullet. That high-tech bullet is MUCH stronger than a typical lead-cored and copper-jacketed projectile like the Match BTHP, and doesn't break apart as readily.

 

[rcmodel]

+1

Different bullet construction.

I have also seen .30 & .50 Cal MG Armor piercing steel cores stick in steel armor at long range.

Some of them penetrate clear through, some of them make a hole almost clear through and bounce back out towards the gun, and some of them get welded in the hole like those.

It's all a balancing act between bullet construction, and impact velocity.

But it's not uncommon with all the same AP ammo, from all the same MG's at longer range.

rc