Recently I was given some .356 diameter bullets supposedly for a .380. My experience has been that the .380 bullet diameter is .355. Will the .356 diameter bullets cause an increase in pressure or will they work at all? Thanks for your expertise and thoughts.

What bullets are they? If they are cast lead in the 85-100 grain range they should be fine, but if they are jacketed bullets I don't think I would shoot them. FWIW

They are FMJ-HP. Can't figure out what would shoot a .356 bullet? They are 95 gr.

Depends who the manufacturer is, also what type of bullet. Most the jacketed 9mm bullets run .355 and .356.

Load them and shoot them, they'll be fine.

For piece of mind you could slug your barrels groove diameter and you may be surprised what you find. Most 9mm pistols I have larger groove diameters then .355

Thanks Luckyducker and SmokinJ for your input. Have a wonderful weekend! Keep shootin!