Blanks shot within should have a decreased noise degree to safeguard Everybody's hearing. Outside the noise have a lot more areas to go for this reason dissipating it greater. I have loaded the 45-70 with 40 grains of FFg black powder over a Styrofoam wad. The reason was to supply https://strapweaponshop.com/product/triple-r-munitions-223-5-56-nato-blanks-100-rounds/