Why are bullet holes gray?

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24 May 2002, 01:49

HenryC470

Why are bullet holes gray?

I asked this the day before we got hacked, and the topic has disappeared, except for a blank line I can find using the search feature.

So far, I had not found out the answer, unless it was:

Target Blood

Burned Paper

The paper around the hole being gray regardless of the bullet being lead, JHP, FMJ, whatever, was perplexing to me and one poster.

Any ideas?

H. C.

24 May 2002, 04:39

Stonecreek

Henry, from the lack of responses, I'd say we're dealing in a somewhat gray area.

24 May 2002, 07:03

Flip

I realy cant think why, seems very intresting

24 May 2002, 07:07

Bucktail

Maybe it's powder residue. It stands to reason that some of the gasses get past the bullet in the barrel, maybe some of them stick. Anybody have access to FTIR?

24 May 2002, 09:35

Stonecreek

Powder residue? At first blush, it doesn't seem likely, but I kinda like the theory.

24 May 2002, 14:12

<Don Martin29>

It might even be lead from the nose of the bullet! I have seen a spiral, pinwheel print around bullet holes from bullets that were melting like using bullets for the .222 Remington at over 3500 fps.

Also I agree that it may be dirt in the barrel from powder residue. I shot a group with a rifle that had been cleaned really well and the holes looked clean. Later shooting showed the holes to be dirty. Also the groups opened up also. But I admit I am having trouble with this rifle.

24 May 2002, 14:47

Pa.Frank

my theory is that the paper is somewhat burned from the bullet "drilling" it way through the paper. I believe that a 30 caliber bullet with a MV of 2900 fps is spinning at about 30,000 RPM

Any mathematicians out there?

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Don't tread on me!
Pennsylvania Frank

24 May 2002, 16:02

tarbe

2900 fps 10" twist

2900F/S X 12"/10" X 60s/m = 208,800 rpm

24 May 2002, 16:53

<Don Martin29>

Bullet length 1.00" , revolutions in paper target 1/10 revolution.

24 May 2002, 17:51

craigster

It's the same thing as running a patch down the bore. The patch comes out grayish black. Well them, so does the bullet. Bore fouling transfers from the bullet to the paper. What's so hard about that. I'm sure this is something we all really need to know. Yeah, yeah, I know, don't be a smart ass.

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there's a fine line between hobby and mental illnes

25 May 2002, 01:36

mbundy

Yes, I believe it is barrel fouling. A few years ago, I heard about a guy who showed up to a BR match with bullets coated in a white substance...His bullets holes did not exhibit the trademark black ring. Some people were concerned that the scorer wouldn't be able to measure them properly...

29 May 2002, 02:16

HenryC470

quote:
Originally posted by craigster:
It's the same thing as running a patch down the bore. The patch comes out grayish black. Well them, so does the bullet. Bore fouling transfers from the bullet to the paper. What's so hard about that. I'm sure this is something we all really need to know. Yeah, yeah, I know, don't be a smart ass.

Craig,

I believe you are right. I figured it was either powder fouling or copper rubbing off on the paper. One thing is sure, the gray bullet holes from 180 gr. Sierra ProHunters do not turn green or blue with copper solvent. I am inclined to believe it is powder fouling and not copper.

H. C.

30 May 2002, 15:24

D Humbarger

Where's OverKill!

02 June 2002, 10:33

<centerpunch>

quote:
The paper around the hole being gray regardless of the bullet being lead, JHP, FMJ, whatever, was perplexing to me and one poster.

There is only one thing that's a constant amongst the stated conditionsï¿½ all bullets leave a grey ring.

Conventional ammunition requires the burning of powder to get downrange. That fouling is the only thing the bullet touches in it's trip down the bore, any grey trace on the target, can ONLY be from powder residue. [Eek!]

03 June 2002, 05:45

Bill Leeper

It is simply a combination of jacket material and powder fouling. These particles are microscopic in size and are primarily powder fouling hence the gry color.
Some BR shooters will color their bullets with black Mgic Marker to make the bullet holes more visible in bad mirage conditions. I have noticed the bullet hole being decidedly blacker when I'm using ball powders. Regards, Bill.