le.atk.com/223data/223rifle.asp?pgtocall=1

Federal did some testing on several of their .223/5.56 rounds, and published the results on the link above. The tests were performed using a Colt M4 with a 14.5" barrel with a 1/7 twist rate at 10 yards.

What caught my eye was that the way that the American Eagle .223 55 gr. performed:

- Against Bare Gel it achieved 14.5" of penetration, velocity was 2869 fps and it only retained 36% of it's weight (fragmented)

- Against heavy clothing it achieve 12.25" of penetration, velocity was 2869 fps and it retained 80% of it's weight (fragmented, but not a whole lot)

- Against steel it penetrated 16" with almost no fragmentation, and against glass it only penetrated 3.25" (not bad compared to what some of the other rounds penetrated).

The reason I bring it up, is because I am looking for widely available alternatives to XM193 which seems to be almost impossible to find anymore. So what do you think? Might this be a viable alternative for use as a defensive round?

To piggy back on your post, AR15KittyKat shot a boar one time with regular WWB 55 grain FMJ.  Not Q3131A and he he also used some 55 grain soft point ammo.  He said even thought the 55 FMJ did not fragment, it actually made more of a mess of a mess than the soft point, due to the yawing. And his normal round he uses IS Q3131A, which does yaw and fragment and make a big mess.  

I will concur with the experts that you should choose the best performing SD rounds but some of the others may do in a pinch.

Thie biggest issue will likely be that since the muzzle velocity is lower than M193, the fragmentation range will be shorter.

Quoted: Thie biggest issue will likely be that since the muzzle velocity is lower than M193, the fragmentation range will be shorter.

True.

If it loses velocity at a rate of 3 fps/yard* and the muzzle velocity from a 14.5" barrel is 2869 fps, then it should have a velocity of 2700 fps at 56 yards and a velocity of 2500 fps at 123 yards.

* I came up with the rate of 3 fps/yard by subtracting the advertised velocity at 100 yards from the advertised muzzle velocity and dividing by the number of yards. Not the most scientific method, but it should be a good estimate.

Quoted: Quoted: Thie biggest issue will likely be that since the muzzle velocity is lower than M193, the fragmentation range will be shorter. True. If it loses velocity at a rate of 3 fps/yard* and the muzzle velocity from a 14.5" barrel is 2869 fps, then it should have a velocity of 2700 fps at 56 yards and a velocity of 2500 fps at 123 yards. * I came up with the rate of 3 fps/yard by subtracting the advertised velocity at 100 yards from the advertised muzzle velocity and dividing by the number of yards. Not the most scientific method, but it should be a good estimate.

Well, I am not expert, but that "sounds" about right.  Given M193 is around 3000fps from a 14.5" barrel, and typically had a frag range of around 90yds, IIRC.

I wonder if there would be any way to quantify a minimum velocity where a projectile will "yaw"/rotate and pass sideways for a significant distance instead of pass through without altering its orientation with respect to its direction of travel.  Even if a bullet does not fragment, a 55gr FMJ .223/5.56mm bullet is going to tear a pretty big hole if passes through something sideways.

Quoted: I wonder if there would be any way to quantify a minimum velocity where a projectile will "yaw"/rotate and pass sideways for a significant distance instead of pass through without altering its orientation with respect to its direction of travel.  Even if a bullet does not fragment, a 55gr FMJ .223/5.56mm bullet is going to tear a pretty big hole if passes through something sideways.

I agree on your question and your point.  

IIRC 2700 fps is the min for 55 grn 223 to yaw

I can't attest to the lethality of Federal AE 55gr, but I can certainly tell you the stuff is accurate as hell.  I usually have 1" to 1.5" groups with it at 75yds. I shot 6 into 2" at 100yds, but I was having trouble seeing that day, my eye was giving me trouble. I have so much fun at the range with the AE 55gr and 62gr, that I'm even stowing 6 mags of it away for SHTF. The stuff is accurate, functions flawlessly and in almost 3,000rnds between 4 rifles I have yet to have a malfunction of any kind.

- rem

Quoted: IIRC 2700 fps is the min for 55 grn 223 to yaw

That's for reliable fragmentation (which also implies yaw).

I'm wondering if there is a lower threshold where the bullet will yaw, but not fragment.

It's entirely possible that it doesn't happen (i.e. yaw w/o fragment), but it doesn't hurt to ask.

Quoted: Quoted: IIRC 2700 fps is the min for 55 grn 223 to yaw That's for reliable fragmentation (which also implies yaw). I'm wondering if there is a lower threshold where the bullet will yaw, but not fragment. It's entirely possible that it doesn't happen (i.e. yaw w/o fragment), but it doesn't hurt to ask.

I think he's confusing fragmenting with yawing. I think it's more than possible that it will yaw out to further ranges than 2700 fps.  

I was under the impression that most of the commercial 55 gr FMJ rounds had a little heavier jacket on them than the M193 bullet... Anyone able to confirm that?

I think that would explain most of the test results, but with that in mind, it doesn't really sound like it would perform the way they said it did on the bare gel and the large amount of fragmentation. I would be interested in hearing from anyone who might know more, or is able to tell me I am wrong in my thinking.

Quoted: IIRC 2700 fps is the min for 55 grn 223 to yaw

Depends on the rounds...some fragment at 2500 fps.  2700 fps is where you get more reliable fragmentation

Quoted: I was under the impression that most of the commercial 55 gr FMJ rounds had a little heavier jacket on them than the M193 bullet... Anyone able to confirm that? I think that would explain most of the test results, but with that in mind, it doesn't really sound like it would perform the way they said it did on the bare gel and the large amount of fragmentation. I would be interested in hearing from anyone who might know more, or is able to tell me I am wrong in my thinking.

Part of that is in the ammo oracle. Especially about wolf.  I can't confirm it but I do believe you are correct.

Quoted: Quoted: I was under the impression that most of the commercial 55 gr FMJ rounds had a little heavier jacket on them than the M193 bullet... Anyone able to confirm that? I think that would explain most of the test results, but with that in mind, it doesn't really sound like it would perform the way they said it did on the bare gel and the large amount of fragmentation. I would be interested in hearing from anyone who might know more, or is able to tell me I am wrong in my thinking. Part of that is in the ammo oracle. Especially about wolf.  I can't confirm it but I do believe you are correct.

Fragmentation at a given velocity is based partially on jacket construction (shape and weight distribution of the projectile are also factors). M193 fragments well because it has a light, thin jacket which is crimped (weakening it even more). Some commercially manufactured ammunition will not fragment due to the heavier jacket that is used. That is not to say however that ALL or even MOST commerically will not fragment due to their heavier jackets. Alot of commerically available ammo has very light jackets and they fragment very well.

Fragmentation is not the only factor in a good defensive round. Penetration is also important. M193 fragments well, and can penetrate to 12" or more against Jello. In the data that Federal supplied from their Jello tests, the AE223 Fragmented (not spectacularly, but fairly well) AND penetrated more than 12". However, as FALARAK pointed out it may not have a very long effective range due to the fact that the velocity is lower than M193.

See, I read the ammo-oracle too!

If you've read the Oracle.

Why are you looking at Fed AE and not Black Hills or Georgia Arms?  Stop looking to the 55gr FMJ and think heavy OTMS.

Quoted: If you've read the Oracle. Why are you looking at Fed AE and not Black Hills or Georgia Arms?  Stop looking to the 55gr FMJ and think heavy OTMS.

I want something that will shoot effectively out of all of my guns. 2 of my AR's (an SP1 and an SP1 clone with a Colt SP1 upper) have 20" 1/12 barrels. The heavier loads have stability problems when fired from barrels with the slower twist.

Quoted: I want something that will shoot effectively out of all of my guns. 2 of my AR's (an SP1 and an SP1 clone with a Colt SP1 upper) have 20" 1/12 barrels. The heavier loads have stability problems when fired from barrels with the slower twist.

Ouch! that pretty much limits you then.

Federal AE looks to be your choice then.

I like the Federal American Eagle and the Federal Classic FMJ loads.

Good stuff!