Gun Barrel Blackening....Fact or Crap?

ozzman

yes, this is 100% true, the more a tank uses its gun, the mored deposits of gases around the barrel. i have no clue y everyone else says its crap. this is a fact proved by many wartime photos.

If there are photos, post 'em.  I've looked at my fair share of armor photos from WWII to the present, and I've served with tanks in a fight.  Never did I notice significant deposits of carbon on the gun barrel.  HOWEVER, I do understand why people model them this way - as Oddmanrush said, it definately conveys the impression that the tank has been in the... poop...

DoogsATX

 

ozzman:

 

yes, this is 100% true, the more a tank uses its gun, the mored deposits of gases around the barrel. i have no clue y everyone else says its crap. this is a fact proved by many wartime photos.

 

 

You may very well be right...I would love to see the wartime photos, since I've never seen one with a blackened barrel and otherwise "clean" tank...but I haven't done a twentieth the research that others have probably done.

Thinking about the physics of it, thought...it doesn't make sense to me. The barrel is ejecting the gasses and particulates, in general, out and away from itself. On a plane, the airflow, essentially a 200-400mph wind for our purposes, forces all that back along the leading edge of the wing, leaving the gun streaks. 

With a tank, there's nothing to push the blast back, and if there was the barrel viewed, uh, barrel-on, would present very little surface area next to the leading edge and flat surfaces of a wing. A more general level of griminess, sure, but that kind of targeted accumulation just seems...difficult to me. 

Same thing applies to battleships. Look at the intensity of some of the barrages lit off up through Desert Storm...but I've never seen the New Jersey's guns half-black with carbon scoring.

I'm curious about the physics of gun smoke streaking the wings of a fighter. If it is moving at 200-400 mph wouldn't most of the carbon/smoke dissipate before having a chance to cling to the wing surface? I've seen gun footage before, and there is truly a lot of smoke expelled from 6 .50 cals in the wings. I can see how the carbon would gather around the openings of the gun ports of a P-51 say, but I can't imagine they would be streaked half way down the wing. 

Doesn't airflow along the leading edge of a wing move slower than the air flowing over or under the wing? This would allow for greater carbon build up around the ports. Similar to how a ceiling fan gathers dust around the leading edge.

This is mostly my conjecture and I'm open to discussion. I'm also not saying that using this technique is incorrect. I'm just curious to know how accurate it really is. The way people build and finish a model is up to them.

Bogus...

WIth a muzzle-brake, there would be some carbon on the inside baffles, but tubes without one are generally pretty clean...

On aircraft with blast-tubes and gun barrels extending from the wings there is little streaking...   As for escort fighters coming back with ammo and the gun-tapes in place, it's not likely...  I know that Dad's unit would expend their ammo on "Targets of Opportunity" on the way back, after they cut the bombers loose...

Yeah, but Navy guys are cleaning those things every half-hour...

ozzman

yes, this is 100% true, the more a tank uses its gun, the mored deposits of gases around the barrel. i have no clue y everyone else says its crap. this is a fact proved by many wartime photos.

You may very well be right...I would love to see the wartime photos, since I've never seen one with a blackened barrel and otherwise "clean" tank...but I haven't done a twentieth the research that others have probably done.

Thinking about the physics of it, thought...it doesn't make sense to me. The barrel is ejecting the gasses and particulates, in general, out and away from itself. On a plane, the airflow, essentially a 200-400mph wind for our purposes, forces all that back along the leading edge of the wing, leaving the gun streaks. 

With a tank, there's nothing to push the blast back, and if there was the barrel viewed, uh, barrel-on, would present very little surface area next to the leading edge and flat surfaces of a wing. A more general level of griminess, sure, but that kind of targeted accumulation just seems...difficult to me. 

Same thing applies to battleships. Look at the intensity of some of the barrages lit off up through Desert Storm...but I've never seen the New Jersey's guns half-black with carbon scoring.

ozzman

yes, this is 100% true, the more a tank uses its gun, the mored deposits of gases around the barrel. i have no clue y everyone else says its crap. this is a fact proved by many wartime photos.

Very interesting. If you have any pictures to show as an example, that would certainly be helpful. Perhaps I've never seen enough pictures of armor after it has extensively used its weapon, but I've not seen much in the way of photo evidence of this at all. But I'm open to it if you can show me.

yes, this is 100% true, the more a tank uses its gun, the mored deposits of gases around the barrel. i have no clue y everyone else says its crap. this is a fact proved by many wartime photos.

Well I was never a tanker or gun bunny. However, I did plenty of live fire exercises around them during my time as a mech grunt , but never was close enough to notice if soot was around the bore or not. I did on one time put LOTS of rounds though our track's .50 in a very short time. That did result in some carbon around the muzzle typical of any extended automatic weapons fire as well as a discolored barrel. But I had to clean it up later.... after all a dirty weapon will jam eventually and that is not a good thing. So I would say some after lots of activity, but not overdone, and not long lived.

Well, first of all almost all escort flights end without guns fired, in WW2. And most good crew chiefs arrange to have a/c cleaned up. And the dopies seal the ports. But if the intent is to show a fighter on the ground, steaming from a fight, fine. There could be smoke streaks.

rjkplasticmod

Can't comment on Armor, but there is photo evidence of streaking on some aircraft, although most models way over do it.  I've never seen photo evidence of streaking on P-47's, but many modelers seem to confuse the blast tubes with gun barrels.

Regards,  Rick

I'd go so far as to say gun streaks are overdone and environmental wear and tear, panel fading under UV light, etc, is underdone. Or overdone in the wrong way. 

Not that I'm not guilty of this myself...

most streaking is minimal. But I'm pretty sure it existed. Just not in quantities that you see on a lot of models. So basicially, I'm in agreement with the above answers.

Can't comment on Armor, but there is photo evidence of streaking on some aircraft, although most models way over do it.  I've never seen photo evidence of streaking on P-47's, but many modelers seem to confuse the blast tubes with gun barrels.

Regards,  Rick

Ok cool, so it seems like we all agree so far. Appreciate the quick responses fellas.

I'm with you on tanks and such.

Aircraft...it depends. A lot of aircraft and especially fighters tend to depict aces' rides so the guns were at least fired. And planes with a lot of area right around the muzzle (P-51s, Corsairs, Hellcats etc with the .50 cals nearly flush with the wings) would be more susceptible. 

The one that bugs me is blackening on P-47s, since the protuberances are blast tubes, not gun barrels. 

^^Ditto.^^

...crap...

...carbon deposits were more common on and around aircraft MG/cannon ports  and can be verified in pics but usually they are overdone in scale models...