If y use a 600 mpa steel encased the steel and or a heavy resin coating stops fibre from expanding increasing resistance. Composites are stringer than elements on their own...Kevlar is generally anti cut and used in Blackhawkes cock pit from memory...
Porcelain tiles with some sort of composite backing. The fracture of ceramics is as important as hardness as it spreads energy. So 2x layers of tiles so edges are overlapped, seperated by either additive or other rubberised resin approx 1/2 tile thickness. Then a fibreglass backing with an overall kevlar wrapper to stop lamination. Prepping the tiles to get good adhesion is important.
Main objective is 2 vs 1 and also does a thin softer layer promote spread and dull impact transmission? The 2 layer is so tiles overlap so no bullet just gets a tile edge and why adhesion is really important, maybe an angle grinder with a diamond cup wheel on that top surface as any prep should be uniform, maybe that hard topcoat is important as floor tiles seem to be rated higher. Maybe paint epoxy individual tiles. The kevlar top layer maybe just 2 weaves of different orientation with large overlaps to form the back. If you can use vac forming as the degassing and consistency are hugely increased with any composite manufacture and stronger. Its not much more than a polyethylene bag but maybe hire? There are other youtubers that have done exhaustive tests on specific material, but as a finnished composite plate often have glaring ommisions. The kevlar wrap is only 2 ply front with multiple overlaps back (20-30 $?) so not the cheapest but more likely to stretch and hold in place and a far more finnished product. Every layer is a composite and just tape as in some vids is a bit questionable to what we are testing as differing effective properties can combine and materials and order likely can make overall difference. Alumina ceramic tile is really interesting but also expensive, but for a youtube especially if little difference would be youtube gold.
I just figured it would be better than plain resin, maybe it would help break the bullet apart. It probably didnt have much effect on the outcome besides additional weight.
Yeah something similar to what you would do on a loom would have been better. I didnt really think about that, this is my first ever video! Learned a lot since then.