Att. Ian; sawdust bullet "catcher"

[Intheshop]

Or anybody who has experienced an "oiled sawdust trap".....

I've got the above necessary ingredients basically running out my ears. I've been spreading waste sawdust on me and the dog's "training run"..... just to get rid of it. And because I'm an idiot, still change our cars/bikes/truck oils here at the shop and have way too much of it.....need a waste oil heater(to thread drift my own thread).....

So,not being exactly overwhelmed with snow banks..... just how good is oiled sawdust for catching CB's driven at obscene velocity?

 

[RicinYakima]

Well, it was done by Harry Pope and Dr. Mann 110 years ago. It is still the best medium. Eight feet long, two foot side and bottom, and open top. It is messy, but it you have a metal detector, you can find the bullets easily.

 

[Pistolero]

Seems like keeping it dry would be the issue if you want it to last, but for free, just keep piling it
on as it composts away.
If for bullet testing only, a modest box with some sort of a reasonably weather tight roof
would seem to suffice. I like the metal detector idea to save time.

Bill

 

[Ian]

You can forget anything Pope or Mann did if considering HV rifle bullets.

I only have a little data but it's way more than what the internet provided me. Basically, you need a LOT of media and the density and grain size is critical. Too much oil and the bullet goes on forever, too little and the media packs up in a shockwave formation similar to shadowgraph images and the bullet disintegrates. What worked best for me (with limitations) was actually a commercial floor sweeping compound which is VERY lightly oiled and made from softwood sawdust which has been de-dusted. Hardwood or ground-up pallet wood material is no good IME.

More about the limitations. I like to shoot soft-ish bullets for a lot of reasons, and soft bullets (air-cooled wheelweights or heat-treated 50/50) start to blow their noses off in sawdust at about 2100fps. They will also lose their gas checks most of the time in all the media I tried. You may find something better, or a better sawdust/oil ratio. The more oil you use, the farther the bullet will travel, which is a good thing for saving the bullet.

Next time I get after this project I'm going to try a more moist sawdust for the first two feet to bleed off velocity a little more gradually and then switch to the as-shipped sweeping compound for the rest.

Six feet of the compound would stop a 140-175 grain bullet from 2200fps in six feet. I used 2" of open-cell urethane foam rubber to contain the compound behind a small hole sawn in the end board. I built a long wooden box with a lid on waist-high legs and put a sheet of corrugated galvalume over the top to keep the rain off. Remember, you will be digging through this stuff up to your elbows at least and you don't want the media to mold. You also don't want to use used oil because of heavy metal contamination...unless you have some gloves with really long gauntlets. 5 gallons of cheap 303 tractor fluid is money well spent. Ya got amy other questions, ask away.

 

[RicinYakima]

Ian, you are right if you want anything more than 1600 f/s. But OP didn't specify "HV".

 

[Bret4207]

Ian, you are right if you want anything more than 1600 f/s. But OP didn't specify "HV".

From ITS OP- "So,not being exactly overwhelmed with snow banks..... just how good is oiled sawdust for catching CB's driven at obscene velocity? "

 

[Eutectic]

I see two avenues of interest here which hasn't really been clarified. One interest would be examining the fired bullet for fit, slump, maybe even measurement. My interests are the second avenue of simulating expansion for big game. Here I use wet newspaper. I like soft light snow for examination. The metal detector might speed up this method over spring thaw!!!

My old neighbor Bob Hagel..... sadly deceased..... used oil sawdust a lot testing in his writings. Fast jacketed stuff too like his old 7mm Mashburn Magnum! I think he was looking expansion but have a vague memory of rifle fit as well. He explained his system in an article once but I don't remember where? Maybe "Handloader"??
I'll ask a couple of really old fellows still kicking who might know..... because they shot with him.

 

[Ian]

Once you get much over 2000 fps, catching the bullets without damaging them significantly becomes quite a challenge. Powder snow seems to be the best thing there is by all accounts. The alternative to snow is hard on HV bullets, however there are two things that can be done to help. One is a very light pre-trap media (possibly Styrofoam beads?) to bleed off speed before the bullet encounters the final stopping media; the other is shoot at longer distances. By 300 yards a 2400 fps 30-cal bullet is going something like 14-1600 fps depending on BC, and at the lower speed is much less complicated to trap intact.

Edit to add: Don't try cotton or poly batting. The bullets wrap up in it and deflect at all sorts of bad angles, exiting the sides of the trap. I always felt it would be a good idea to put a steel lid on the trap to keep bullets from deflecting up and possibly leaving the range safety zone.

 

[fiver]

ITS is pushing the limits pretty good with a couple of his rifles.
I'm wondering if a high[er] oil content and more length to the box wouldn't be a better catch medium in the long run.
that way instead of just slamming on the brakes before hitting the brick wall you could throw it in neutral and coast to a stop.

 

[fiver]

and we just typed the same thing at the same time again.

 

[Ian]

Yep. We almost did it the other day on Rodmkr's thread, right after he started it I started out to say his range officers are a pretty sorry lot for not offering to help him carry his rifle safely, but didn't post because I had no helpful ideas to offer in his unfortunate predicament.

 

[fiver]

I kind of didn't have anything too constructive either but it made me a little mad at how they were treating him.

 

[Ian]

The problem I had with adding more oil to the sawdust for more gentle stop is it makes the sawdust heavy and it packs under its own weight. The sawdust can only be made so light. I'd like to understand exactly how it is that snow is so good for this and try to find something to duplicate it.

 

[fiver]

it depends on the snow.... LOL.
well it does.
I know your not gonna understand this so much but there is different kinds of snow.
I never seen a 'snowflake' shaped snowflake until I went to north Dakota.
the moisture content in the air and the speed with which the flakes are formed make them have different crystalline structures and more sharp shapes.
a lot of the snow I deal with can be 2' high but only have 1" of water in it.
or it can be such a high water content it forms blue ice just by packing down on itself like a glacier.
in between those is the good bullet catching material, you want a decent moisture content, but not wet, something just shy of snowball making capability.
kind of like good dirt that will take a ball shape in the palm, but then crumbles apart when you put the thumb to it.

 

[Ian]

I've experienced "powder" snow a few times in SW Colorado. I remember stopping at the pullout on Coal Bank pass, and feeling a bit mischievous, tried to pack a snowball to throw at my wife. Imagine me, who has spent a lifetime in Thermopylae, staring stupidly and uncomprehendingly at the white powder stuff in my hands that would not stick to itself at all no matter how hard I mashed it. I've also encountered the slightly more damp powder which would make a ball but crumbles apart like you say if you touch it at all. Weird stuff that powder, and it will fool you too if you don't know to wear Nylon gaiters when trekking through the stuff in jeans and leather boots. It's fine for half a mile kicking through the powder but after a bit the body heat starts to melt the stuff and next thing you know you got wet, freezing ankles.

 

[Eutectic]

it depends on the snow.... LOL.
well it does.

Does it ever! Must be why the Eskimo's have 50 different words for it!

I can watch it snow and take a look at outside temp and know whether it will 'plow' nice or lousy!

Duplicating snow may be as complicated as cast bullets!

Sometimes I have gone out to the 300 yard county rifle range just as winter's snow cover had melted. Just walk around looking down at the wet ground. I've seen some weird examples! One that comes to mind was a .338 Nosler Partition. It must have penetrated a fair length as the nose was pristine... It appears it lost stability and then went backwards! The flat lead exposed base mushroomed just enough that the bottom core came out! The example defied all logic! I thought about sending it to Nosler and ask them what happened. I gave it to another and didn't get it back or I would take a picture...

 

[Intheshop]

Velocity is from 2500-3100.

I could dual purpose a metal detector purchase.....err,not that we miss targets with arrows... you know,for a friend?

Don't have the burning desire to test the oil to sawdust ratio,too much. The box or housing is a no brainer.

I'm positively going to shoot some snow banks next winter.

Is shooting into a 55g,filled water barrel out of the question. We have plenty of elevation.... barrel out back,fill with hose,shoot out of second floor window.

 

[Intheshop]

And in a perfect world.....

What I also need,if in some way could make a "trap" that..... even if it meant a quick disconnect(shortening length for practicality) is a "tube" arrangement that can be used in loading room.... or somewhere inside? for cycling loaded rounds. I always go outside and got a lazy streak that begs to come up with an acceptable,over engineered from a safety standpoint,pipe of some sort.

Now,if it could double as a bullet catcher.....

 

[Rick]

Is shooting into a 55g,filled water barrel out of the question. We have plenty of elevation.... barrel out back,fill with hose,shoot out of second floor window.

I tested a `1911 45 by shooting straight down into water and if collecting the bullets to examine is the goal water isn't the answer. Not too far from shooting concrete. At 900 fps I got dramatic expansion with HP's and the 068 didn't expand at all but went through the water and through the bottom of the drum. Had to place steel plates on the bottom the next barrel and then the 068's flattened out. In that regard it was an interesting experiment and showed the penetration difference between HP's and a solid nose. It also showed me the difference in alloy's with the HP's, 12 BHN blew the nose off, 8 BHN formed complete mushrooms. Little doubt though that those complete mushrooms had ANY penetration, they no doubt opened up on the surface of the water and then just sank to the bottom.

 

[Ian]

Supposedly Richard and John Lee collected bullets for examination by firing into their backyard pool. I have always doubted the water trap for that purpose for cast bullets, especially not having seen any photos of what they recovered.