I don't think I've seen this addressed here, but I am new to this forum and I am not well versed in it's search features.
1) I can get 55gr training ammo in quantity in .223 for a lot less than 55gr 5.56. Is there any reason I should prefer the 5.56 ammo over the .223? If it matters, all of my goto SD ammo is heavy OTM .223 (specifically BH 68gr and 75gr MHP).
2) I understand from Doc's threads that two of the best rated .38 rounds for snubby's are the 110gr +p DPX and the 135gr +p Gold Dot. I've shot both in my 642, and both are controllable. How does the 110gr, driven fast, penetrate rougly the same as the slower 135gr, and yet a 115gr +p 9mm can over expand and under penetrate?