Quoted:
Quoted: ispchoser1,
Both M193 and M855 require a relatively high impact velocity for their terminal effects to be, well, effective. If I remember correctly, violent fragmentation only occurs when they hit at over about 2600-2700fps. Hence their range is limited in M4 and shorter barrel lengths.
The data presented here shows that the 100gr bullet remains terminally effective to a much lower impact velocity.. sound like even as slow as 2000-2200fps, it's still good - maybe lower is okay.
Doing the numbers, and taking some on faith from those who have posted or hinted at the "military-spec" loadings here, the 100gr load should be effective a ways further than M193 or M855. However, it has been said that this round is intended for CQB primarily.
-z
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I don't think the fragmentation abilities of the 100gr will reach much farther than M193/855. Yes, it may frag at much lower velocities but it also starts out at a much lower velocity. I think the big advantage of this load is its increased frag dynamics (due to the larger surface area presented when moving sideways through the target) and wounding potential when compared to M193/855 but still within the same 200m range.
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Sorry to differ with you.
100 grain has turned out FAR better. We've got some more tests we'll put up eventually. We've done quite a lot of range testing as well as introducing some very creative changes in the load and we now find that the current load is still fragmenting at 2050-1950fps (!!!). Given the very favorable ballistic coefficient the round also enjoys, this means a far better fragmentation envelope than M193 not to even mention the drubbing it gives M855. I'm not going to give out specific data now since we don't have enough for me to be comfortable standing by any specific figures right now- but I can say that effective fragmentation distance (fragments 85%+ of the time) looks to be quite a bit beyond 200m.
The actual disadvantage of the 100 grain round is it's trajectory. Huge drop out past 400 meters. Enough at 200+ to make shooting gel... well... interesting.
For lone actors, it's currently my round of choice- and I am VERY picky. It's the most tissue damaging round I've seen in .223 and it meets FBI specs nicely. This includes through heavy clothing and some light cover we've tested.
We are probably going to do some side by sides with the best 3 or four rounds we've tested so far, and based on these results we'll test the hell out of the "winner" and, personally, I'm going to stock up on that round for my own use.
This, of course, was originally the point of testing. To find out what round actually WORKED for my needs- to cut through the hype.
Just for your reference, my criteria are:
1. Lone actor/self defense threat model.
2. Escape and Evasion for any encounter over 200 meters, unless "back to the walled." In this case, however, I expect to be in a last line of defense dwelling and therefore using 7.62 (155 grain AMAX- far and away the best 7.62 for terminal effects) for those shots. I wouldn't carry that around in a SHTF scenario though- too much bulk.
3. Potential "close" encounters with heavy clothes and soft body armor (performance against denim/IIa and IIIa NIJ armor).
4. Potential "close" encounters with aggressors in automobiles (performance on autoglass)
5. 1:7 barrel twist. 16" barrel- this is a personal choice based on my ability to deliver quicker followups than with 20"
6. Ability to obtain/make at least 7500 rounds for stocking purposes and another 1000 per year for training purposes.
7. Muzzle flash.
Perhaps an AR15.com bulk purchase will follow, if people are interested.
The other issue, of course, is the limited availability of 100 grain. It's pretty much "load yer own" right now. We'll see what we can do about that.
[moderatormode]I do urge people to be careful making guesses and assumptions about round performance without data. That's how ballistics "LORE" gets started. "I saw someone say that..." Pretty soon it becomes FACT, despite the fact that no source, supporting data, or peer review exists. Pretty soon you have "I've got a friend in the special forces who says..." Ugh.
Without the BC and real gel testing you can't say much about the performance of a round at range given only a velocity of fragmentation thresholds. People look here for answers and newbies might not know any better. Let's not perpetuate myths, ok?[/moderatormode]