[Update] Iron Filing Bbs Confirmed (Not Steel Cored)

[Rogerborg]

Wow, always something new.  Seen on a Facebook forum, an unnamed site (might be in Scotland) has found some BBs on site that are metal covered in a blue coating.

They didn't catch the culprit, and that's all I know for now.

[UPDATE]  Further information has emerged, and on dissection these aren't steel cored, they are homogeneous blue BBs, probably Valken, and doubtless bought in good faith.  A lad yesterday also got "caught" using "metal" BBs which again turned out to be grey 0.36g (I believe) Bulldog, again with nothing to indicate the content.  They were yeeted off site (the player wasn't, but left in a sulk anyway) because they're not bio.  Or at least not labelled as bio, my scepticism about the whole "biodegradable" BBs thing is on record.

It seems like sites are going to have to acknowledge and deal with the reality that "plastic" BBs are only plastic if you don't look too closely.

A chap on site made the reasonable observation that iron or steel is likely more biodegradable than PLA under woodland conditions.  I agree, and now actually think these metal-dust BBs are fine, if we accept that it's OK to play with BBs of that mass at all.  They have to have some bulking agent in them, and iron is at least honest and can be identified.  If your heavyweight BBs aren't magnetic, it doesn't mean that they're all plastic, just that they have Mystery Mass.

[ORIGINAL]

Obligatary "Ban em, ban their mum, ban their kids, ban them unto the 7th generation".  And watch out for anyone flogging shady blue BBs, because it's just possible that they've bought them not realising what they're made of.

But here's something to ponder. A 4.5mm / .177" steel BB would only mass about 0.38g.  Put a 0.75mm thick coating on it and you've got a 6mm BB that would mass in the 0.4Xg range.

So... is that actually worse than a "plastic" BB of the same mass?

Because given that 6mm of ABS only masses about 0.12g and 6mm of PLA about 0.2g, all heavier BBs have to be adulterated with something denser, right?

I've often wondered what that is, and I can only assume that it's metal or ceramic/mineral dust.

At some point I'd have to question what constitutes a "plastic" BB.

If you're horrified by the idea of 0.45g steel cored plastic covered BBs, are you OK with 0.45g "plastic" ones?

I'm really not sure what to make of this.

 

[Asomodai]

I do not know anything about physics and material dynamics, but wouldn't a plastic coated bb, be easier to come apart on impact creating shards, especially with a harder/heavier material inside? With the ceramics in the plastic we use now, its all mixed in. 

 

[Rogerborg]

Quite likely, yes.  Although I've got some PLA bio BBs that - after a couple of years in the garage - have started to crack and crumble and there seem to be a distinct outer shell on them that's breaking up.

I've love to see some detailed analysis of exactly what's in the BBs that we're buying, and not from the folk flogging them to us.

 

[Adolf Hamster]

y'know this is an interesting question, think a mate of mine is doing some work with fillers in polymers will ask him see if he has any info as to what it does to the mechanical properties.

 

[hitmanNo2]

I wonder if someone got on Alibaba and sourced something like these

https://www.alibaba.com/product-detail/Wholesale-plastic-rubber-coated-steel-ball_1600073098106.html

 

[Rogerborg]

I wonder if someone got on Alibaba and sourced something like these

https://www.alibaba.com/product-detail/Wholesale-plastic-rubber-coated-steel-ball_1600073098106.html

Quite possibly, although I'd hope that nobody deliberately bought them for airsoft use.  But that said, I honestly do wonder if rubber coated steel is any more hazardous than adulterated "plastic".  Heck, it might even be safer for all we know.

 

[Adolf Hamster]

Quite possibly, although I'd hope that nobody deliberately bought them for airsoft use.  But that said, I honestly do wonder if rubber coated steel is any more hazardous than adulterated "plastic".  Heck, it might even be safer for all we know.

Question comes down to how much do our bb's deform at airsoft energies.

Wonder if work would mind me stealing the high speed camera for a little while.....

 

[Rogerborg]

That would be fascinating to see.  So much of airsoft is based on assumption and magical thinking, I'd love to see some actual evidence.

 

[Speedbird_666]

Manufacturing such a BB would be a complete ballache.

If the steel core was not perfectly centred within the plastic moulding (thus creating an off-centre centre of mass), then you would get some very odd ballistic results when spun through the hop unit.

 

[Samurai]

According to my extensive research (first hit on google) https://www.amazon.com/Chrome-Steel-Ball-Bearings-G25-25/dp/B01AX6VTFU

6mm steel ball weighs .88g

To use that weight, the gun needs to be quite powerful, over the firearm limits, to be able to put a reasonable backspin on it, IMO.

The other problem is that steel doesn't deform, it transfers all of the energy upon impact. Think of Newton's cradle (pic). Plastic BBs deform, even shatter upon impact that uses up a lot of its energy.

There were clear plastic Bioval BBs available until banned, long time ago. They were very rigid and they could shatter windshields and windows, even with their low weight, low speed.

Question comes down to how much do our bb's deform at airsoft energies.

I don't know, but I think a gold ball is harder than a BB and of course it doesn't shatter, but plastic deforms quite a lot.

 

[SSPKali]

This is a job for TheSlowMoGuys... <laughs as the entire forum now spends their day watching the cool videos on their Youtube channel  >

 

[Lozart]

1 hour ago, Samurai said:



I don't know, but I think a gold ball is harder than a BB and of course it doesn't shatter, but plastic deforms quite a lot.

Golfballs aren't harder than a BB. The outer shell is relatively soft and the inside is really quite elastic. Which is why they don't shatter!

 

[Adolf Hamster]

That would be fascinating to see.  So much of airsoft is based on assumption and magical thinking, I'd love to see some actual evidence.

this is the thing, i have a suspicion some of the harder bb's like geoff's don't deform much on impact, but i have no evidence to back that up.

problem is i work in a uni, so pinching expensive equipment to do a homer is questionable and i sure ain't doing that kind of test on-site for obvious reasons.

6mm steel ball weighs .88g

To use that weight, the gun needs to be quite powerful, over the firearm limits, to be able to put a reasonable backspin on it, IMO.

yes and no, for our current crop of hop designs most likely it'll be difficult to put enough backspin on it yes given the average airsoft contact patch is so short, but i've had guns that would send .48g's to space on 1j  so it's not out of the question that lifting heavier than that within reasonable limits is possible.

I don't know, but I think a gold ball is harder than a BB and of course it doesn't shatter, but plastic deforms quite a lot.

golf balls aren't solid, they're filled with rubber, so not really comparable to a bb.

there's also the issue of the target- what area are we most concerned about when it comes to a bb strike?

a hard strike against steel would only really represent a gun hit, and lets face it we don't care about those from a safety perspective.

proper eyepro (as in stuff that is of suitable rating for airsoft) is tested to resist a steel projectile, so it's not really relevant there.

so really the impacts that matter are bare flesh and clothing.

 

[BigStew]

so really the impacts that matter are bare flesh and clothing.

Would add teeth to that list a plastic BBs can do serious damage to your smile.

 

[Adolf Hamster]

Would add teeth to that list a plastic BBs can do serious damage to your smile.

true, although i'd argue 2 points:

-given our plastic bb's can already do that, a heavier/stronger bb isn't going to make it worse.

-[kickingmustang] anyone who isn't wearing face protection is willingly taking on that risk [/kickingmustang]

 

[Rogerborg]

According to my extensive research (first hit on google) https://www.amazon.com/Chrome-Steel-Ball-Bearings-G25-25/dp/B01AX6VTFU

6mm steel ball weighs .88g

But a 4.5mm is only 0.38g, plus a 0.75mm shell of plastic, rubber, or just thick paint.  It's actually a construction I'd considered before (to make the point that it's equivalent to a ~0.45g "plastic" BB).  I just didn't expect anyone to be lunatic enough to use it.

Manufacturing such a BB would be a complete ballache.

If the steel core was not perfectly centred within the plastic moulding (thus creating an off-centre centre of mass), then you would get some very odd ballistic results when spun through the hop unit.

That's the baffliing bit, why would you use them?  Surely they must have cost more than plastic / "plastic" BBs.

I wish I knew more about the cirumstances, it's very curious.

 

[Shamal]

Personally I can't see how these balls have any bearing on the sport.?

Regards 

 

[Adolf Hamster]

Personally I can't see how these balls have any bearing on the sport.?

Regards 

that was a ballsy move, but it's nice to see the gears of comedy still spin freely in the modern age.

edit: as a side note, was chatting to my mate and he was suggesting there's about a 25% change in hardness with the stuff he's been working on.

different polymers to what we're using but loaded up with iron nanoparticles up to 35% (forgot to ask if that was by weight or volume)

he also made a point that fillers aren't the only way to increase density, i'm not a polymers guy and i got lost somewhere at the point where he started talking about chains being different lengths but the gist of it seems to be you can just make it more dense without adding anything, although not sure what the limit was (ie wether or not you could double the density for example)

 

[Rogerborg]

Apologies for the potato-cam quality, this is swiped from Facebook. 0.43 ASG "plastic" BBs. 

View attachment 74910

 

[Adolf Hamster]

Apologies for the potato-cam quality, this is swiped from Facebook. 0.43 ASG "plastic" BBs

it's also why afaik a lot of the heavier ammo comes in "stealth" config, whilst some manufacturers can do the heavies in lighter colours (presumably with a different filler) a lot of them are like that.

never thought to try something as simple as testing them with a magnet.