Since my 1:9 (actually 1:8.75) won’t shoot the 75gr TAP nor will my pocket-book support it, would the best available option with military surplus ammo would be to stagger M193 and M855?
I have considered testing some 68/69gr loads, but not only does nobody have them for a good price nor do I have the reloading setup yet.
According to some tests at close range M193 does better than M855 with penetration. On my rifle the POI of M193 and M855 are good out to 300yds within about 2MOA or less.
Good idea?
Also, where can I find definitive comparative data on M193 vs M855 on windshields, car doors and other intermediate barriers?
Here’s what the RKI’s here are going to tell you. Don’t do it. It’s unnecessary and serves no purposes for a variety of reasons. Each type is different and they both have their own characteristics.
Among which are different points of impact at various ranges given the same point of aim. It is all about shot placement. Listen to sinister talking about RUAG:
I do not see the point of going through all the trouble either…
As stated above, both perform poorly through auto glass and similar “hard” barriers. Use what you can get your hands on.
When working up close and nasty I know several dudes that use mixed mags, but the rounds they are mixing are much more effective at their intended purpose and they have a very specific application in mind. The difference between M193 and M855 is so little it makes the argument moot.
If I needed ammo that is compatible with a 1/9 I would take a look at the 62 gr Federal bonded JSP Tactical (LE223T3). It is expensive, but it does better thorugh intervening barriers than either M855 or M193, and gives a very consistent wound profile. Since it is so expensive I would invest in enough for a few mags worth and to zero, as well as check POI at relevant distances in comparision to whatever you can get for training.
Take a look at the 5.56 mm Duty Loads in the Terminal Ballistics section, as recommended by DocGKR. Lots of very good info.