Been trying to find papers about how they make ballistic gel for research purposes - found this paper which described a bit how they made it.
However, there is no NATO standard for gelatine and therefore “20% gelatine (by mass)” should be used. That 20% gelatine is stiffer than 10% gelatine
If you want to replicate the Clear Ballistics block, you’re gonna need 6.8 kg of gelatin.
The rest of the paper is actually an interesting read - they tested 9mm, 223 & 7.62x39
G’day
The reason I want to use the gel is that it’s transparent and I can photograph the wound channels.
I know someone who has access to a high frame rate camera and if they can sweet talk the owner into letting me shoot near it I can get slo-mo of the temporary cavities as well.
I’ll have to read that report this arvo, supply run to zombieland today.
There seem to be barriers I hadn’t anticipated, including the expensive gelatin, but I’ve been told I’m a persistent bastard, whether they meant a bastard who’s persistent or that I’m persistently a bastard I don’t know, but I will not be denied my jelly fun.
It begins.
Slowly.
This is half the amount needed for one 10% block or one quarter of a 20%er.
PS
Just thought I’d put it out there, will trade sex for the right weight of gelatin, nothing kinky, I’ll supply the goat.
I’ve been doing some reading and searching and one thing I can’t find.
What is minimum testing range and is it different for every caliber?
I don’t want to build my $100 wobble block only to detonate it first shot
Then I found this:
How to make allistics gel
Says 10ft in the article.
Sounds a tad close…
Opinions welcomed
Well my thoughts would be that if you are looking to see how different bullets perform (in regards to wounding game) then you would need to put the BG at the range you would be expecting the game to be at. Its the only way the projectile will hit the gel with real world velocity and energy.
If you wanted to compare the power of different calibres then 10 ft may be suitable.
^^^^^^^^^^^^^
This, all day!
I’d expect 3m being suggested for pistol rounds.
You want usable terminal analysis, test at predicted terminal range…
Yes, my thoughts have been of all the possible variables there are for testing criteria and, in an ideal world, that’s how I would set it up.
The main question though, from my pov at least, is to get the most relevant results comensurate with my limited resources.
Testing at long range, while something I will eventually do, is an order of magnitude different as far recording video of the impact is concerned for just one example.
I’d love to film the respective imacts at given ranges to see incremental energy transfer changes(I also get off on statistics) but I’m a one man band here and my only choice is a smartphone or a dslr.
The other thing I have to consider is that at $100/block I can only afford one and the quality of the results rely on one shot per block per test with the block needing to be cut up, debrided, remelted, recast and aged 72hrs between uses.
PS
I just did some discouraging reading on minimum frame rates for ballistic gel testing of centrefire rifle ammo.
For example, if I was using a 10,000 frame per second camera, a .223 pill travelling at 900mps will move 9cm between frames.
If I want to actually observe the impact with any usability I’d need to raise that speed by a factor of at least 10 using something like the camera below.
Sweet baby Jeebus, I love the sudden epiphany.
I’ve been sulking about how much these blocks are going to cost me after one quick glance at the recipe.
I venture among the walking dead again on Thursday so I sat down and actually worked it out properly for the first time down to grams per litre 
The old imperial measurement had tricked my tiny mind.
I only need 100g of gelatin per litre and the 6"×6"×25" mold I built will hold 14.78lt or ~1500g per block at 10%.
I already have 1800g in the 3 tins I bought last time.
This means, if I can get another 3 tins this time, I can run 2 blocks at once for the same cost I expected for one.
Now all I need is a lotto win to get a high frame video camera…
My life runs on 3 basic rules, Murphy’s Law, Catch-22 and the Law of Unintended Consequences.
Adjudicated by the Bad Fairies.
After crowing yesty about epiphanies, 2 blocks, blah…not one but 2 drive belts parted on the way to town today, spare cash for gelatin is now turning my alternator and steering.
Back to 1 block, mixing tonight, melting the bloom and pouring tomorrow night, 72hrs to set.
I’m starting with .22 and I think the 12.5" depth of half a block should suffice for them even at 50m.
Any advice or suggestions welcome
The mold with liner
The Gelatoid Mixatron
The Gelatoid
When it’s had time to contemplated its future, I’ll scrape the bubbles and start melting 
Jelly
Like I needed something else to hate.
Smug in the knowledge that my liner had passed the leak test (with cold water) I half filled the mold with hot liquid jelly, no leaks, sweetnesss, poured the rest, still no leaks and smug self satisfaction rapidly reaching stiffy level.
That’s when the aforementioned 3 rules came to visit.
I was starting to clean up and turned around for another gloat and saw the level had dropped and there was jelly making a break for it in all directions.
Buster Keaton had nothing on the slapstick shitstorm that ensued.
There are few surfaces in the kitchen that don’t have at least a trace.
The lino will have to go, tried to mop it off with hot water and went tits up.
I’m currently considering whether it would just be easier to set the joint on fire.
To salvage something I grabbed a couple of compartment trays from an old fridge and put what I could save in them.
Further.
Chaos, tantrums and cleanup finished, I decided to try a different method with the 300g of powder remaining and instead of blooming etc, just mixed it up in 3lt of hot water and poured it into plastic containers.
Much less fuss and fuckery and it seems much clearer.
Here’s the results of both
I shouldn’t be laughing at your misfortune. I should be a better person than that.
I should
Oh Gaz you poor bastard. As a moonlighting cook I am learned in the ways of hot liquids and thin flexible plastics. You live you learn as they say.
You can still make the mold you want, just use melamine from bunnings, cut and screw together and follow with some silicone on every single square edge join. I learnt this the hard way too, and believe me epoxy sucks when its not where you want it.
Maaaate, when you’re cleaning up, there’s this point along the line between where the set jelly is quasi solid and where it’s melted where it’s sort of sticky but persistently slimy at the same time.
Something the Men in Black might have to clean up after an orgy at an alien embassy.
Or the phlegm from hell.
The 2 small blocks came out OK, the big ones are still in the fridge.
I think the smaller of the 2 is a bit too small so it will go in with the first remelt but the other is going to be my first test.
Subsonic .22 at 50m.
I can’t see the point in shooting from 10 feet, it may be easier but as I don’t do any furry murders at that range, I agree with those who suggested common hunting range testing.
I have mopped the kitchen 3 times and there are still small spots of snot, invisible to the eye but ice to the boot heel.
First test, Sellier Bellot. 22 subsonic 40gn HP.
Blew right through the 17cm of the larger of the small blocks at 50m, sweet looking permanent wound cavity but I’m having dramas trying to light the block to highlight the channel for photos.
I’ve tried white light from all angles, same with sunlight.
No amount of fiddling with exposure, light etc after taking makes any difference.
Any camera buffs got suggestions, I’m about to try red or green, the only colour filters I have.
Further.
I took some shots of the first block with a dslr instead of the phone, using sunlight, but my old laptop is having a bad hair day so I can’t access the card yet.
First of the big blocks came out of the mold well, bit cloudy but…
Big block 1 is now two 4x4x12" blocks
Discovered why the Youbeauty camera on my new phone wasn’t doing the job, fucking jelly on the lenses.
The pics below are the best I could render from the images I took of the first shot; Sellier and Bellot 40gn subsonic HP at 50m.
Entry is at the red dot to the right, expansion appears to begin at the first pair of green leaving a permanent wound extending to the second pair of green with the exit at the yellow dot.
