Can anyone tell me what the muzzle velocity and ballistic coefficient is for XM556FBIT3M from am 16" barrel? I want to get a custom elevation turret for my scope and i need to know this. Also, if you know what the muzzle velocity for xm855 green tip from 16" barrel? Thanks for your help.

M855 is 3000 fps from a 16 barrel.



M193 is 3100 fps from 16 inch and Leupold already makes a scope calibrated for this, hope this helps.

BTW... I think it is actually XM556FBIT3.... No "M"On the end... might help with your Goggle search for BC....https://www.google.com/search?q=XM556FBIT3&rls=com.microsoft:en-US:IE-Address&biw=1093&bih=513&source=lnms&sa=X&ei=fnqQVOimIomwogSC_YLYAQ&ved=0CAUQ_AUoAA&dpr=1.25

5.56 mm Fed 62 gr FBI TBBC JSP (XM556FBIT3) fired from 16" 1/7 barrel AR15 at an av. MV of 2920 fps

Muzzle velocity... no problem... also listed in the FAQ at the top of this forum.... http://www.ar15.com/content/page.html?id=213

62-69gr

Brand and headstamp on brass..............................16 " Velocities ( FPS )........20" Velocities ( FPS ).........Comments......,,,,,,,,,,,,,,, NC means NATO CROSS

AMA, 62gr M855...............NATO AMA 12..........................Av. 2889 , ES 31.........................Av. 3005 , ES 42............ Good accuracy for M855

Carl Gustav..62gr .............NATO 12-CG-10.......................Av. 2944 , ES 30..........................Av. 3044 , ES 56.......... Still not sure what to think of this ammo.
This is the Swed. "Green Bullet" Very long for its weight.

Fed. 62gr XM855............ NATO LC 13...........................Av. 2967 , ES 73.........................Av. 3040 , ES 82........... Typical Milspec 2-3 MOA
Fed. 62gr MSR Fusion .223.....FC 13 223 REM...............Av 2828 ...ES 54.........................Av 2918...ES 34............ Short stroked twice.
Fed. 62 FMJ .223 Lead Core....FC 13 223 REM..............Av. 2739, ES 73..........................Av. 2761, ES 34

FNM 62gr SS109..............FNM 91-1 NC..........................Av. 3009, ES 34..........................Av. 3118, ES 44.............Gawd, I miss cheap surplus

GGG 62gr M855...............NATO, 5.56 13 GGG...............Av. 2930 , ES 62.........................Av. 3028 , ES 66.......... Ok, I expected better accuracy.

Hansen / PPU 62gr ..........IK .223R..................................Av. 3004, ES 67..........................Av. 3153, ES 68............

Hirtenberg 62gr SS109....HP .223 5.56............................Av. 2965, ES 71.......................... Av. 3000, ES 68 ...........

Hotshot 62gr....................SADU 13 5.56...........................Av. 2919, ES 83..........................Av. 3057, ES 70

IMI 62gr M855.................TZZ 89......................................Av. 3008, ES 44 ..........................Av. 3192, ES 23.............Very accurate for M855.
IMI 62gr FMJ5.56............IMI 13 2 digits.......................... Av 2964.....ES 60..........................Av 3077....ES 32 ...........VERY accurate for 62gr M855

PMC XTAC 62gr...............PSD 14...................................Av. 2885, ES 38...........................Av. 3051, ES 48...............Both XTAC rounds have changed my opinion of PMC "A"

Turkish ZQ1 62gr FMJ.....MKE 14....................................Av. 2892, ES 38...........................Av. 3026, ES 55

Winc. 62gr M855 ............WCC 88....................................Av. 2944, ES 76..........................Av. 3058, ES 56.............

Nosler 64gr BSB .223 .....NOSLER 223 REM..................Av. 2511, ES 58...........................Av. 2560, ES 44.............Not super fast, "A" grade for accuracy.

SSA 64gr BSB 5.56........SSA 5.56...................................Av.2572, ES 109..........................Av. 2570, ES 68............. Had to drop the hammer twice on one round in the 20"..... "A+" accuracy.

Winc. 64gr BSB 5.56......WCC 13 5.56MM........................Av 2883... ES 62.........................Av 2978....ES 25............ Very good accuracy and speed.

Ultramax 68gr..................SPLIT NECKS ON ALL except for the ONE FULL NECK SEPARATION.............................Granted this is 15 years old ammo and maybe they are better now ?!

Fed. 69gr GMM................FC 13 223 REM.......................Av. 2585, ES 30............................Av. 2780, ES 32............. Outstanding Accuracy.. "A+"

PPU 69gr 223...................PPU 223 REM.........................Av. 2564, ES 34.............................Av. 2685, ES 80.............."B+" Accuracy

STRICTLY guessing on the BC for the TBBC 62 gr ....using Nosler's 64gr BSB info, similar in shape , meplat, etc........ .231 BC

M855: Defined in MIL-C-63989 a 61.7 grain at a velocity of 3,000 fps from a 20" barrel @ 78 feet from the muzzle. Ballistic coefficient is typically .304.

I bought 15 boxes of brown box XM556FBIT3M ammo. Dont know what the m means but thats the part #. Does anyone know?

Link to where you found it? The vendor's description might give us a clue as to what they mean by tacking that M on.

Makes me wonder if it's not reloads using pull down bullets.

Federal says its not reloads or rejects but that it is the same exact buulet/load as the fbi contract

Anyone know the muzzle velocity for federals le223t3 round from a 16" 1-7 twist barrel? Ive read 2690 fps and 2970 fps. I also called federal and they said that it was tested from 24" barrel and it was 3050fps. They said take 25 fps off for each inch of barrel shorter so it would be 2850 fps. Any help on this would be much appreciated!

I gave some to bluefalcon for gel and chrono testing along with a few other rounds (like the black hills 77gr tmk round that was recently posted. Hopefully he will be able to test it in time, recognizing he has a busy schedule.

One thing I can say about the round is it feels hotter than any other 556 round shot. Not sure why. It's very obvious when alternating with 5.56 75gr tap which is the t3  and which is not.

I agree with this. It feels and ejects brass like a pretty hot load. No flattened primers, but certainly hotter than 855.

2953 FPS with a standard deviation of 15 FPS for a 10-shot string.

BC = 0.224

That seems like an unneeded expense when you're guessing about velocity.

I'd expect to put a lot of rounds downrange personally verifying POI in my gun at different distances and only then getting a custom turret if I was obsessed about dialing range in at extreme distances (400 and out since a BSZ can have you close out to 250 - 300) and only then if I was able to shoot to the accuracy potential of the rifle/ammo combo.  As others have said there are a number of optics that already have BDC's and/or turrets pre-set for a 62gr bullet from a 16" barrel.

Interesting. I've thought it was a hot load when I've fired some of my stash. Thanks for the conformation. Nice to see it's consistent as well.

I can confirm that it will pass through 3 layers of drywall, insulation, outer sheathing and a brick façade and continue on it's merry way.

Yes, I'm a dumbass.