I bought some XM556FBIT3M from Target Sports USA that came in a .223 pressure loading. This is different from my 5.56 pressure TBBC that I have. Is there a significant difference in velocity or terminal performance between the 5.56 and .223 loadings? Is the .223 loaded FBIT3 as good as the 5.56 version?

I’m confused. If the part number is XM556FBIT3, then it should be loaded at 5.56 pressure.  Were you told different?

Maybe the same exact bullet is used in a 223 hunting load since it's originally a hunting bullet (Bear Claw).

There is probably 100-200 FPS difference. But the 223 load is probably more accurate. But I'm guessing and will stand by for actual data.

Looks like XM556FBIT3 is .223 and XM556SBCT3 is 5.56 pressure.

https://www.bonefroggunclub.com/products/556-62gr-federal-tactical-bonded-xm556sbct3

https://www.targetsportsusa.com/federal-fbi-duty-556-ammo-62-grain-tactical-bonded-sp-xm556fbit3m-p-109726.aspx

The batch I got (think the designation ends with an M and is .223) is pretty anemic. I'd have to check, but I want to say I was getting low to mid 2400s out of an 11.5" suppressed.

For comparison, the 64g Gold Dots I tested on the same day netted a solid 100fps more.

It's .223 loading:

Well that sucks, Guess I’ll just have to order the 5.56 stuff from bone frog gun club and just shoot the .223 stuff as expensive range ammo.

Realistically, it's going to perform well even though it's 100fps slower.  It's a solid bonded design that will expand just fine.  So while I would prefer the extra 100fps, it's not a big deal and I certainly wouldn't relegate it to range ammo.

Interesting.  I think the “M” denotes .223 pressure as the original FBI contract round was 5.56 pressure.  The SBC round was a different solicitation and is intended for short barrel carbines.

Deciphering all the various product numbers for the various FBI/T3 loadings is a bit challenging without solid info from the manufacturer. I asked our resident Federal expert for some clarification in this thread but haven't received a reply.

From what I can tell, XM556FBIT3M is indeed a .223 pressure load since both the box and the case headstamp are marked .223 REM. The FBI seems to have started purchasing this instead of the original 5.56 pressure XM556FBIT3 as early as 2015 (maybe earlier) based on some contract awards I found.

I'm not totally clear on the SBC designation. Bone Frog says XM556SBCT3 is the same thing as XM556FBIT3 with the SBC simply indicating that it is not FBI-contract ammo. However in a thread from last year, a reliable source said that the current FBI contract round was .223 pressure XM223SBCT3, which throws a bit of a wrench in things as far as product numbers. He did note that they switched to the .223 load because it was more accurate.

Regarding usage in SBRs, testing in short barrels has been one of the requirements for the FBI contract for almost a decade. FBI's 2010 solicitation that led to the adoption of XM556FBIT3 mentions that the ammunition will be evaluated in weapons with barrels as short as 10". A 2015 RFP (which also confirms that XM556FBIT3M was the current duty round at that time) notes that ammunition will be evaluated in 11.5" barreled rifles, including a test for optimal penetration and expansion in ballistic gelatin at 100yds. That solicitation resulted in a $15 million contract award to Vista Outdoor (Federal's parent company), and smaller awards to Winchester (presumably for RA556B) and Hornady, so I'm confident that the .223 pressure T3 load performed well in their testing.

FWIW, DHS/ICE have also selected a .223 pressure T3 load with yet another unique product number as an "enhanced" duty load with a 62 grain Gold Dot-based load as their "standard" duty load.

Damn good info @DiscipulusArmorum.

As for the original question, the .223 version will be just fine for self defense, you might lose a bit of range but as @Zhukov said it won't be much. IIRC these rounds expend reliably down the around 1800 fps.

Thanks!

1800 fps is the number I've generally seen given for the expansion threshold for Gold Dot/Fusion soft points. There's a Youtube video showing a calibrated gel test with reduced velocity handloads using pulled Fusion projectiles that showed robust expansion at ~1700 fps.

For the the T3/Trophy Bonded soft point, I've seen numbers reported anywhere from 2000 fps to "at least 2200 fps or so". The Trophy Bonded projectile is generally considered a "tougher" bullet than the Gold Dot with slightly better performance through barriers, so the slightly higher expansion threshold would seem to be analagous to what we've seen with the optimized 50 grain TSX loaded by Black Hills. It's designed not to shed petals through auto glass like standard TSX and has a higher expansion threshold than the other TSX projectiles.

The SBC loads were intended for FBI HRT teams, who were using primarily 11.5” SBRs. The load was optimized more to reduce flash, possibly some other changes in the powder. My memory on that solicitation is a little fuzzy.  I do have some of the ammo at home. Haven’t shot it yet.

Perhaps "SBC" then stands for "short barrel carbine"? I seem to recall hearing that the FBI has tried to standardize all their 5.56 carbines to 11.5", which would jive with the fact that the 2010 duty ammo solicitation lists a hodgepodge of guns in different barrel lengths for testing while the 2015 solicitation only lists two 11.5" guns. That solicitation does mention that the new ammo would be tested to make sure it had equal or lesser flash than XM556FBIT3M.

Check out the link below. Good info in description that explains the nomenclature of the different FBI 5.56 and 223 loads.

XM556SBCT3

There is at least one inaccuracy there. While there were some batches of XM556FBIT3M sold a few years ago that were labeled as factory seconds, that product number in and of itself does not denote a factory second. The 2015 solicitation I linked before notes that "Current FBI service ammunition is Federal Cartridge, 62 grain Tactical Bonded, product number XM556FBIT3M"

The other unanswered question is whether or not XM556SBCT3 is really the same as XM556FBIT3 as some sellers are stating. A poster above suggests the SBC load was tweaked a bit for the 11.5" guns that are now the standard FBI carbines, which makes me think it was the ammo selected in response to that 2015 solicitation. I don't ever recall seeing the SBC load for sale before then. The claim that SBC denotes a non-FBI contract load seems to be contradicted by a reliable source stating last year that the current FBI duty load was XM223SBCT3.

The .223 load referenced by Eagle Eye Guns (LE223T3) is a commercial off the shelf ammo that was in use with the FBI and other state/local agencies before the FBI put out their RFP in 2010 that led to XM556FBIT3. It uses the same projectile, but is loaded in a nickel-plated case.

ETA: Just wanted to note that while these minutiae are of interest to us ammo nerds, I really doubt that all these variations make any significant difference beyond a few edge cases. TBBC in any flavor is an outstanding choice. To quote DocGKR:

From the very informative posts above, I compiled the following:

XM556FBIT3: "Standard first run, USG contract 5.56 mm 62 gr bonded JSP ammo for the FBI and other Fed LE agencies is XM556FBIT3--so much for "x" meaning rejected..." DocGKR

XM556FBIT3M appears to be the .223 version of XM556FBIT3. ""The 2015 solicitation I linked before notes that "Current FBI service ammunition is Federal Cartridge, 62 grain Tactical Bonded, product number XM556FBIT3M"" "Federal says its not reloads or rejects but that it is the same exact bullet/load as the fbi contract." AR15.com Some XM556FBIT3 was sold in cartons marked "Factory Seconds" in 2016. These cartridges were said to have failed to meet the FBI's accuracy requirements, and some of these cartridges purchased on the civilian market appeared to have quality issues.

XM556SBCT3 appears to be a different solicitation of XM556FBIT3 that is intended for short barrel carbines. "The SBC loads were intended for FBI HRT teams, who were using primarily 11.5” SBRs. The load was optimized more to reduce flash, possibly some other changes in the powder." (Eagle Eye Guns first carried this cartridge in the summer of 2013).

XM223SBCT3 appears to be the .223 version of XM556SBCT3. "... a reliable source said that the current FBI contract round was .223 pressure XM223SBCT3...He did note that they switched to the .223 load because it was more accurate."

Anything missing or inaccurate?

Really good terminal performance, not very accurate in anything I have. 3-4 minute ammo.
Perfect for SD. Sketchy distance load. I used to hunt it down but Fusion is a better load IMO.

Wasn't Federal Fusion designed specifically for deer hunting?

It's marketed for hunting use, but it has the attributes of a good self defense load. Same projectile design as Gold Dot (now that Gold Dot has switched from 64gr to 62gr, I would bet it's the exact same projectile). Uses a sealed and crimped Gold Medal Match AR primer. Low flash powder that does well in short barrels (as shown in this excellent set of data.

ICE is using XM223SP1PB, which seems to be virtually identical to Fusion (not sure if it uses the GMM primer though).

The Trophy Bonded Bear Claw projectile used in the FBI load/Federal Tactical line started out as a hunting bullet as well. Nosler Partition and Core Lokt Ultra Bonded are two other hunting bullets with ideal characteristics for anti-felon purposes that come to mind.

Thanks DiscipulusArmorum

Of course!

One thing I forgot to mention, there are two versions of Fusion. Fusion MSR is the one that is optimized for use in ARs with the aforementioned crimped, mil-spec hardness primer and better velocity in shorter barrels. Regular Fusion uses the same bullet and is by no means bad - it just doesn't have the bells and whistles that make Fusion MSR a bit better for our purposes.

Same here.

From videos I have watched, the 223 version out of a 10 inch runs 2279 ( Buffman), and out of a 10.5 the 5.56 runs 2576 (The Chopping Block).  I have a couple hundred rounds of the 5.56, but I lean more to  Fusion MSR.

I find it hard to believe that there's 300fps difference between the two loads, short of some very significant lot to lot variation or chronograph inaccuracies. The FBI contract calls for a load that meets their penetration and expansion standards (12-18" and 2x original diameter IIRC) at 100yds out of an 11.5" barrel. Given the B.C. and relatively high expansion threshold (at least compared to Gold Dot/Fusion), I don't think the .223 load could meet that requirement if it's really that slow. Or maybe it really loses a ton of velocity going from 11.5" to 10".

I had less than favorable results when I tested the FBIT3, but that was probably almost ten years ago. During my testing of the 5.56 loads, the RA556B was the most accurate, followed by the FBIT3. As for the 223 loads, Speer 64gr won, followed closely by the xm223sp1 with the fusion bullet,really good stuff.

Andrew always gets #s higher than me. I tested some ".223 spec" IMI awhile back on the same day I tested their 5.56x45mm loading, and there was a 112 fps difference coming from the 10.5" barrel.