General ammo question x 2

[Moonshot]

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?

[wilco423]

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).

Using 223 is fine, as long as it functions well in your rifle. Some cheap 223 won't work in rifles optimized for full power NATO loads. Just keep in mind that there will be a trajectory and therefore zeroing difference between your practice and SD loads. Probably not a significant difference at 50yds, but will likely be huge at 200. If you zero your rifle with the practice stuff for training, just make sure you rezero with the SD stuff when you're done. JM2C.

[Chuck Haggard]

Using 223 is fine, as long as it functions well in your rifle. Some cheap 223 won't work in rifles optimized for full power NATO loads. Just keep in mind that there will be a trajectory and therefore zeroing difference between your practice and SD loads. Probably not a significant difference at 50yds, but will likely be huge at 200. If you zero your rifle with the practice stuff for training, just make sure you rezero with the SD stuff when you're done. JM2C.

^This^


and reference the pistol bullets, short answer is; bullet design.

[Chefjon]

As for question #2, I don't know the science. I do now that the DPX is a *solid copper* bullet. I'm sure designs and velocities have to do with it as well. I also found (can't remember where) that 125 +P Rem GS passed as well. Much cheaper. Also in Doc's article in the stickies, hard-cast wad-cutters in heavy weights seem to be gtg as well.