Bullets.....OSB.....fire?

[bobm]

For the second time in one month, today a club member reported that the 7/16" thick OSB paper target backer board self ignited and caught fire burning all the attached paper targets. They were able to extinguish the fire with dirt and their drinking water.

I remained skeptical until I googled for any information. Has anyone else had this happen on your ranges? We are three years into this use of OSB without incident.

Including results for bullet causing fire on osb board
Search only for bullets causing fire on osb board


AI Overview


Bullets, particularly those with steel components, can cause fires on OSB (Oriented Strand Board) and other wooden target materials through high-speed impact and friction, which generate sparks or intense heat
. These, often referred to as "smoldering fires," can ignite paper, debris, or the board itself.
Key Causes and Risks:

• Bullet Type: Solid copper, steel core, and steel jacketed bullets (like "green tip" M855) are the highest risk, as they generate sparks upon impact. Lead-core, copper-jacketed bullets have a lower, but not zero, risk.
• Target Material & Debris: OSB is combustible. When used as a backing, accumulating debris (paper, cardboard, trash) behind the board can be ignited by sparks.
• Impact Heat: The friction from the projectile breaking apart and interacting with the wood can create enough heat to cause smoldering.
• Incendiary/Tracer Rounds: These are specifically designed to burn and will ignite materials on contact.

Safety Recommendations:

• Avoid shooting in dry, windy conditions.
• Ensure target areas are free of dry vegetation.
• Periodically check for smoldering in your target backing.
• Avoid using steel-core ammunition on wooden backstops.

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[ebb]

News to me, but maybe the high relative humidity here in the swamp prevents that situation?

 

[spencerhenry]

I call b.s.

I've cut hundreds of miles of osb, and shot millions of nails through it. Dull blades, sharp blades, nails hitting steel, nails hitting concrete, never even close to lighting on fire. The public range I used to go to used it, never seen it, never heard of it.

AI is often complete and utter B.S.

 

[CJ6]

No mention of tracers starting OSB on fire???

 

[Jonnyofalltrades]

AI is often complete and utter B.B.S.

I can't agree more.
It often comes up with complete garbage.

 

[Tangent]

No mention of tracers starting OSB on fire???

Tracer was the first thing I thought of.

 

[charlie b]

Have not heard of it, but, not convinced it could not happen. Out here in the desert it is easy to catch things on fire.

Our range uses black fiber panels for backing. Seems to be the stuff used on exterior wall construction.

 

[spencerhenry]

Have not heard of it, but, not convinced it could not happen. Out here in the desert it is easy to catch things on fire.

Our range uses black fiber panels for backing. Seems to be the stuff used on exterior wall construction.

I believe you are referring to celotex. I'd think that would be easier to start on fire, we used to call it corn husk board. With or without the thin asphalt coating.

 

[bobm]

This and the other fire 30 days ago was not tracer ammo caused.

We are looking into the gray soft Homosote, which is hard to locate a local source, and black Celotex which is readily available. We just spent $750. for a six month supply of 4x4' OSB panels.

What other search engines are out there for info on bullet caused OSB fire? I am at the mercy of AI Google. Any one care to copy and paste their findings?

 

[M-61]

For the second time in one month

My thought ( never saw it, based on lots of decades experience, not scientific proof) is the club member or members failed to mention they fired tracers.

 

[joshb]

This and the other fire 30 days ago was not tracer ammo caused.

We are looking into the gray soft Homosote, which is hard to locate a local source, and black Celotex which is readily available. We just spent $750. for a six month supply of 4x4' OSB panels.

What other search engines are out there for info on bullet caused OSB fire? I am at the mercy of AI Google. Any one care to copy and paste their findings?

I think the shooters are lying to you. 40 years as a hands on builder working with OSB since it came on the market. Never had a “fire” or anything close!

 

[ebb]

Not sure why OSB or anything for a solid backer is needed, I always did it with a solid backer but the Florida Wildlife Commission does not. They use a 2x2 frame that is made to the size of a cardboard backer. Most of the recreational shooters use a shot-an-see target available at the sale desk when paying range fees, others that use a paper target and are provided tape or use a staple gun to secure target to the cardboard.

 

[Knotwild]

In this day and time - trust people like Joshb, M-61, and Spencerhenry. Or buy some OSB, gather up some bullets, and bang away. Once a group huddles and makes decisions, herd mentality sets in.

Or, if it makes the herd happy, buy this -
Flame Resistant OSB

 

[charlie b]

I believe you are referring to celotex. I'd think that would be easier to start on fire, we used to call it corn husk board. With or without the thin asphalt coating.

Yep, it is. Had to look it up. Good insulator. When used it requires a fire resistant layer of some sort.

But, I've never seen a fire on our range despite all the steel ammo, tracers and other stuff flung at it. And that's in an area that is dry as a bone. Another downside is it soaks up water like a sponge and disintegrates.

Could be that it offers so little resistance to the bullets that it doesn't heat up at all from the passage through the board. Maybe if a .22 tracer got stuck in the board?

 

[Shifty6br]

I call bs on the spontaneous bullet combustion theory.

Tho there are many in the world smarter than I.

 

[dellet]

Probably due to Chinese glue, like the drywall fiasco a few years ago.

For what’s it a worth here’s a taxpayer funded study that might actually be worth about half what it probably cost. Bottom line they found a way to reasonably check the temp of bullet fragments off steel and were able to create fires by lining the bottom of bullet traps with flammable materials.

It might actually be possible for a bullet fragment trapped in a glue pocket to smolder and ignite. I’m probably not the only one that has found steel fragments in OSB among other garbage.

Two instances at the same range In a short time frame is reason to suspect both the shooters and the material. Are they shooting a fracturing or frangible bullet? Maybe there is a glue issue with the OSB?

Link to study.

https://www.fs.usda.gov/rm/pubs/rmrs_rp104.pdf