Range Report 140 Berger keyholed at 100 yards

[JvT_404]

Hi

Went to the range today with a buddy. He was shooting 140 Bergers (older thin jacket with the 0.64 BC on the box) from a 6.5x284 custom gun.

The gun was shooting a blast (around 0.5MOA) at 100 yards, until it threw one shot about three inches high, and the bullet cut the paper a perfect horizontal keyhole - clearly the bullet went through the target completely sideways. The rifle recoiled normally - so we're not sure that it was a reload problem (this guy is a reloading perfectionist).

Has anyone had this before? Dud bullet perhaps?

Cheers
Jaco

 

[Poundcake]

Re: 140 Berger keyholed at 100 yards

There are a couple possibilities, can you give us anymore details? Barrel length and twist perhaps?

 

[JvT_404]

Re: 140 Berger keyholed at 100 yards

26 inch 8.5 twist barrel. Gun has been shooting 140 Bergers perfectly for over a year. This was the only time this type of thing happened.

We were shooting at about 2700ft elevation and around 80 degrees F - bullets running at 2975 on the chronograph, and seated about 10 thou into the lands. A sweet spot load on that gun.......

Cheers
Jaco

 

[BryanLitz]

Re: 140 Berger keyholed at 100 yards

Probably a bullet failure.

Sometimes when bullets 'blow-up', they don't completely disintegrate right away. Sometimes a tear can develop in the jacket as a result of a sharp rifling. If the core is hot enough, some material can melt/vent out the crack causing imbalance, tumbling, key-hole.

Bullet failure is more likely to happen in rifles with higher round count (rougher bore), so the problem in your rifle is likely to get worse.

The solution is to move to the Target VLD's with the thicker jackets.

Take care,
-Bryan

 

[JvT_404]

Re: 140 Berger keyholed at 100 yards

Thanks Bryan.

Given that this was the first time that this has happened, we'll monitor this closely. If it happens again, we'll definitely switch to the thicker jacket version.

Out of interest, and since this particular rifle is used for hunting, has Berger gotten any feedback on the hunting performances of the new thicker jacket bullets?

Regards,
Jaco

 

[BryanLitz]

Re: 140 Berger keyholed at 100 yards

Jaco,
The thicker jackets haven't been tested for terminal performance, so we can't say exactly what they would do on impact. One could speculate that the 'common sense' thing is they would expand to a lesser extent than the thinner jackets expand, or maybe not expand at all. Bottom line is we don't know.

I wouldn't necessarily rule out your rifle from shooting the Hunting bullets in a hunting application. The failures usually happen only after sustained firing when the barrel gets real hot. The failures hardly ever happen within the first 5 shots, which for medium/big game hunting is a practical maximum. Of course I wouldn't advise a hunting application where you do shoot many shots in a row (varminting).

So you may find the solution is to use the Target bullets for the long strings of fire (target shooting) and use the Hunting bullets for applications where you need reliable terminal performance. The bullets are identical on the outside so they will load the same and fly the same. Just be careful to keep them labeled and separated so you shoot them in the right application.

Take care,
-Bryan