Introduction
Writing this has reminded me of the 1986 movie “Aliens” where one soldier, Hudson, asks his commanding officer, “Is this going to be a stand-up fight, sir, or another bug hunt?”  Enough of the movie nostalgia . . .

Ten or more years ago, when my kids were young and still at home, we had a frightful plague of grasshoppers.  This being Texas, everyone knows “everything’s bigger in Texas” and these grasshoppers where no exceptions and were eating everything in sight.

Wanting to entertain the kids inexpensively while (very marginally) helping control the problem, I spent some time thinking about what we could do.  The kids and I enjoyed shooting “those flying disks” in the hay pasture, as they called it, so shotguns where a plausible option.  What ammunition would be appropriate for the task at hand was the pressing question.  Obviously conventional shot would be costly, needless, and potentially dangerous.  First, I tried Couscous as it is pretty hard in the uncooked state, and certainly biodegradable.  But it proved too light to carry any reasonable distance and lacked kinetic energy and penetration.  Eventually I hit on the idea of loading 20-gauge shells with a tiny bit of powder and glass bead blast media for the "shot."  It is about the right size and right specific gravity to make a relatively safe but lethal (to grasshoppers) "bug load!"  The whole family had hours of good clean “splattery” outdoor fun that year and many other years since shooting grasshoppers!

I am convinced, my boy, who is a fine young man now, is a much better shot in the dove field than me because he'd take those shells into the hay patch and flush and shoot grasshoppers on the wing!  This article won't be so much a load recipe but is intended to be general guidance on loading shotshells with glass bead blast media for successful "bug hunts.”  Bugs are not quite as dangerous as those Hudson and his mates encountered in “Aliens”, though we do have some pretty nasty critters here.  Best be armed when one encounters this hombre:  https://www.youtube.com/watch?v=Nw9ZEgSJopg  Jack may let it crawl on him, but I have other ideas.

As you are reading this it is likely you have some experience with shotshell reloading and this is assumed, so, many details such as the need of a new, live primer, won’t be addressed herein.  The focus is on the ejecta and, to a lesser extent, powder, and charge weight.

Glass

Glass bead blast media is made of soda-lime glass, same as a windowpane, and comes in many sizes of spherical beads.  Soda-lime glass has specific gravity normally 2.4 to 2.6 depending on the manufacturer’s formula.  For comparison, according to the American Institute of Steel Construction manual the specific gravity of steel is 7.85 and lead 11.37 on the heavier side, Aluminum being 2.65 on the lighter side.  These values will vary a little depending on the alloy.  You wouldn’t want to use aluminum beads because they will oxidize, and aluminum oxide is a common grinding wheel abrasive.  It could prove to be a little hard on the bore.  So, glass is dense enough to carry a little distance, round enough to pattern well, small enough for a pattern dense enough to cover small critters with multiple hits, and soft and gentle on the barrel. 

https://www.rapiddirect.com/blog/bead-blasting-finish-basics/  https://pittsburghsprayequip.com/blogs/pittsburgh-spray-equipment-company/glass-bead-blasting-pros-cons-common-uses-equipment-needed   

It is also inert, environmentally friendly, and totally non-toxic. 

https://clemtex.com/media/category-pdf/Glass%20Beads/SDS-Swarco-Glass-Beads.pdf

Size is measured by “mesh size” which is the number of openings per linear inch of the wire mesh used.  The lower numbers the less and larger the openings.  Hence, larger beads that can pass through.  20/30 means it can pass through a 20-mesh screen but not a 30-mesh screen.  20/30 is also known as “Extra Course” and “#3”.  This is as large as glass bead blast media comes.  20/30 mesh glass is advertised as being 0.023” – 0.033” in diameter.  Compare that to shotshell shot:  #9 is 0.080” and #12, typically used in .22 rimfire shot cartridges, is 0.050”, 20/30 is just about the right bug size.  Glass bead blast media is available from Clemtex https://clemtex.com/blasting-media/glass-beads  Composition Materials https://compomat.com/glass-beads/  Walmart https://www.walmart.com/ip/BLAST-O-LITE-BT-3-Glass-Bead-Media-20-30-Mesh-5-lbs/615619191?wmlspartner=wlpa&selectedSellerId=9722 and no doubt others.  The photo above is Swarco 20/30 from Clemtex.  Regardless of where you purchase it be sure to get glass beads and not crushed glass.

Loading

Now we will get into building a shotshell.  I will use nearly new components so the photos look a bit better though I normally would use hulls that are nearly burnt out for this.  No sense wasting good components when we can save them for the field or range.  These are Multi-Hull from Ballistic Products Inc.  https://www.ballisticproducts.com/Cheddite-20ga-2-3_4-16mm-brass-primed-and-skived-bag_100/productinfo/1392070/  made by Cheddite in Europe, but anything will work.  Use what you have.  Being a Reifenhauser type it has more internal volume and no taper in the tube walls.

You will use your press for decapping/resizing, priming, wad seating, and crimping operations only.  Because of the very small powder charge weight you probably won’t have a bushing small enough.  A powder meter or small scoop will be needed.  Also, do not try to run the glass beads through the shot hopper and bushing.  It is a bit too fine and will likely get in between the moving parts and cause the bar to hang up.  You will want a scoop for measuring out the glass as well.

Powder

The powder is not particularly important except that it needs to be a fast burning, high nitroglycerin content, double base type.  Because the total ejecta mass is very minimal there will be very little pressure, way more than an automotive tire for sure, but way less than a typical shotshell load.  An “explosive” powder (yes, I know that isn’t a technically correct term, but you get the idea) that becomes fully enflamed virtually instantly will work best.  Don’t hesitate to try any of the first 20 on this list:  https://loaddata.com/Article/BurnRateCharts/Powder-Burn-Rate-Chart-NEW/159  I doubt there is much difference in the burn rates between any of those but do use good common sense.  Norma R-1 could be substantially faster than Solo 1000 for instance, and under this “unusual loading condition”, no one can know for sure what might happen.  You will have to determine the best charge weight for whatever powder you will be using. 

I use Bullseye because that is what I have.  I have had a one pound can for some thirty years.  A little goes a long way!  I started with ten grains of Bullseye, and this gave a very sharp muzzle report which told me I was getting a good burn.  I then went to eight grains and had good results.  I recently tried six grains, and this gave a quite soft report.  All work but I like eight grains better than six or ten.  Seven grains might make a nice compromise.  Keep in mind this is for 20-gauge, if you want to make glass bead loads for other gauges you will need to do some experimenting.

Wads
Pick a wad that fits your hull, is inexpensive, and has a fairly large volume in the shot cup.  If you have compression formed hulls, like Remington STS, you will probably want a Claybuster or similar wad because the gas seal fits the tapered interior better.  For Reifenhauser hulls I use Ballistic Products BW20 https://www.ballisticproducts.com/20ga-Brush-Wad-250_bag/productinfo/072BW20/ as they fit straight interiors tighter and, with no shot cup, it allows for a greater volume of glass beads.  Don’t worry about wad pressure as the powder volume is so small the wad likely won’t reach the powder and double base powders don’t need to be packed like you would expect with a powder for a heavy field load.  Seat the wad enough to barely jiggle the scale.  This will give some consistency of volume.  Or you may want to crush the cushion portion of the wad to increase the volume available for glass.  Wads for non-toxic shot have a large volume shot cup too.

Adding the glass

e are photos of my homemade glass scoop.  It is, obviously, a cut down hull with a piece of carbon arrow shaft super glued to it.  I knocked the spent primer out and put a couple layers of cellophane tape over the flash hole to keep the beads from running out, then reseated it.  It is sized for a volume comparable to that of a 1 1/8-ounce lead shot bushing.  You will have to determine the correct volume for your hull and wad combination.  Then you can cut it down to that volume or cut it long and stack overshot wads in the bottom until it is the correct size.  You could try an adjustable shot dipper as well.  I don’t have one so I can’t say how well they work.  My scoop holds 0.26-ounce of 20/30 mesh glass and is what I use for Reifenhauser hull loads.  If I’m loading compression formed hulls and CB1078-20s I put an overshot wad in the bottom of the scoop first.  This then delivers 0.23-ounce of glass. 

use a little plastic funnel to add the glass.  A powder funnel works well.

Overshot wad

Overshot wads aren’t as common as they once were when roll crimping was how factories sealed shotshells.  However, they are still readily available.  https://www.ballisticproducts.com/Overshot-Cards-500_bag/productinfo/OS/   You will need these for two reasons.  The glass beads move around readily under the folds so you won’t be able to get a consistent crimp, and the beads are small and can easily escape.  The overshot wad will fix both these problems.  If you don’t have them and don’t want to place a special order, go to one of the hobby crafts stores and buy a paper punch like this:  https://www.joann.com/fiskars-corner-lever-punch-small-round/2412716.html then make your own from the cardstock on the back of a writing tablet.  Be advised, too thick of cardstock will break the punch.  I had one that punched a 5/8” diameter hole and the coins were perfect for 20-gauge until I broke it trying to punch too thick of cardboard.  With other gauges you may not be so lucky to find a good fit. 

As with any shotshell reloading you will need to pay attention to the “unfilled” volume over the ejecta to get a satisfactory crimp, then crimp as usual. 

Shooting
As with any shooting sports, do observe all the safety rules and ensure you and everyone around has proper eye and ear protection.  And don’t shoot the dog in the rump just to see if he howls!

I tried to make photo of the pattern from ten yards with a modified choke.  But the holes are small and even with the sun directly behind the paper they didn’t show in the photo.  The average velocity of my load with 8-frains of Bullseye and 0.26-ounces of glass bead media is 941 FPS.  Lethal range on insects will vary with the insect’s size and exoskeleton.  Some are rather delicate while others are quite hard.  Grasshoppers on the fence are penetrated consistently at 20 yards.  Flying red wasps generally go down out to about 15 yards if I do my part.  I did hit one that went down across the fence that was 20 yards from where I was sitting.  A lucky accident, I’m sure.  I can’t say how consistently fatal the hits are because the dead red wasps are hard to find in the grass.  I have found several floating in the swimming pool with holes in the wings and thorax or abdomen.  Rather rewarding that.

Be advised these loads are very dirty.  I think we can all agree that all the high nitroglycerin content powders burn dirty under the best of conditions.  With very little pressure in these loads there is even less thorough combustion.  At least it cleans up easily.  If you’re doing this for your children or as inexpensive off-season target practice, the dirt is worth putting up with.  I’m sure there is some flying pest wherever you live that will provide entertaining and challenging shooting.  If it’s hornets, just don’t shoot the whole hive.  You probably won’t be able to reload fast enough!

Now that the kids are grown and gone and the doves are few, I've been sitting in the corner of my tractor shed shooting red wasps (https://a-z-animals.com/blog/red-wasps-in-texas-identification-where-theyre-found/) as they come and go.  I get a kick out of it even if the kids aren't home, and its good practice, I believe.  Currently there are no Asian Giant Hornets in Texas, that I’m aware of anyway.  However, I’m prepared should they find their way!