What does this mean? Little grey swirls by my bullet holes on target.

[koger]

Went out today, to zero a Savage LA I had installed a new take off factory sporter barrel, 8 twist. I did not do break in, 10 shots to zero, 25-100yds, then shot a 5 shot group. Group was decent since I just did a zero off a portable rest, with bull bags, .628 center to center, 5 shots, in a horizontal group. I then shot a couple of small rocks 4" or so in size pushed into a red clay bluff, 300yds away and hit both them first shot. Looking at the target, I noticed little grey tails at the edge of each bullet hole. This looked like a lead pencil smear, anyone enlighten me as to what this is, what it means.?

 

[bigedp51]

Take a close up macro photo of the bullet holes, your asking us to really strain our physic abilities and today I have a head cold and my physic reception is very cloudy.

 

[chevytruck_83]

OMG. Theres powder burning behind the bullet.. teasing. My guess is you have carbon or even some sort of lube in the barrel. Run clean patches through and you should have your answer.

 

[koger]

I think the culprit might be moly. I had headspaced the barrel, then test fired with some 142's I had loaded, Moly coated for my bull barrel 6.5x284, nothing on the 120's I was shooting.

 

[amamnn]

rock dust--what else?

 

[243winxb]

bullet failure issue ???

http://benchrest.com/showthread.php?49336-Berger-bullet-failure-test

 

[koger]

243, that is what I am talking about, but not that bad, very faint, half that size. I had read somewhere long ago, that you might need to increase the charge. I was getting sooting on the necks, light, not bad. Also holes in the target were perfectly round, not too sooted as in the pic above.

 

[Macropod]

Looking at some the photos it looks like the bullets aren't completely stabilized.

 

[STS]

Re: bullet failure issue ???

http://benchrest.com/showthread.php?49336-Berger-bullet-failure-test

I always call those comet tails. As 243s post suggests it's jackets failing. If you take your rifle out again and look over the top of the scope and shoot 2 or 3 rounds you may see a slate grey "smoke trail" behind the bullet. My worn out .17 Mach IV barrel was doing that every shot before I canned it.

 

[Ledd Slinger]

Looking at some the photos it looks like the bullets aren't completely stabilized.

+1. Wobbling like crazy! Definitely not stabilized.

Comet tails may be from what others suggested. But either way, you definitely need to use a different bullet.

 

[Macropod]

Looks like it is key-holing too...

 

[CatShooter]

The comet tails are coming from the jackets splitting in the rifling groves - it is common with fast twists, and or thin varmint jackets.

 

[jpretle]

or maybe a rough bore, seeing its last days.

 

[M14AMU]

Looking at some the photos it looks like the bullets aren't completely stabilized.

Yep! Not stable!

Read Mann's book!

 

[wolley]

So if I'm reading correctly you installed Savage factory barrel?
The caliber is 6.5 x 284?
I think what you're seeing is a bullet that is just about to fail. The marks are from lead coming out of the jacket.
Savage barrels can be extremely rough and can cut the jackets on thin jacketed bullets.
Bump that load another 100fps and you'll probably get total failure.

 

[Changeling]

Send the picture to savage and suggest it's time to increase the quality of there barrels !!

 

[M14AMU]

So if I'm reading correctly you installed Savage factory barrel?
The caliber is 6.5 x 284?
I think what you're seeing is a bullet that is just about to fail. The marks are from lead coming out of the jacket.
Savage barrels can be extremely rough and can cut the jackets on thin jacketed bullets.
Bump that load another 100fps and you'll probably get total failure.
[/quote

+100

 

[GLShooter]

Those are coming unglued thanks to the fast twist. Shoot 100 bullets and 97 will print. I can get this issue with 50 VMAX at 3750 in a 1:8 224 bore.

Greg

 

[243winxb]

Little grey swirls by my bullet holes on target.

Blowby from a larger than normal groove diameter may let hot gas past the bullet. Powder burns near 5000 F degrees. As the nose of the bullet melts, the air friction will have lead coming off the tip of a spitzer bullet as it goes down range. With this condition, look for a rifle that needs about 10 fouling shots to start grouping. In 243 win. the 85gr didnt keyhole, but some 70gr match bullets did, hitting the 100 yard target side ways. The NRA at the time confirmed this with another shooter having the same problem as i. Rifle was a 1965 vintage Win. M70 heavy barrel i picked up used.

 

[CatShooter]

Re: Little grey swirls by my bullet holes on target.

Blowby from a larger than normal groove diameter may let hot gas past the bullet. Powder burns near 5000 F degrees. As the nose of the bullet melts, the air friction will have lead coming off the tip of a spitzer bullet as it goes down range. With this condition, look for a rifle that needs about 10 fouling shots to start grouping. In 243 win. the 85gr didnt keyhole, but some 70gr match bullets did, hitting the 100 yard target side ways. The NRA at the time confirmed this with another shooter having the same problem as i. Rifle was a 1965 vintage Win. M70 heavy barrel i picked up used.

The nose of bullets do not melt...