With advancements bullet technology and pistol braces have led to short barrels being increasingly popular and a more viable option for SD/HD. I have done a good bit of research on how defensive rounds would work in short barrels and compiled a list of range and data to show the capabilities you would get using them with a 10.5 inch barrel in hopes that it will help others in their decision making process.
I have listed the info in the order and format shown in the line below
Name/Grain - G1 Ballistic coefficient - Approx Muzzle Velocity and foot pounds of muzzle enegry from a 10.5 inch barrel - Expansion Threshold - Approx range for expansion when using a 10.5 inch barrel.
Federal TBBC XM556FBIT3 62 grain *(5.56) .224 ( ballistic coefficient) - 2557 Fps (muzzle velocity) 895 ft lbs (muzzle energy) - 2000 fps (Expansion threshold) - 150 yds (approx. range for expansion)
Federal Fusion MSR 62 gr- B.C. .31 - 2504 fps - 860 ft lbs - 1700 fps or less - 300 yds
Black Hills TMK 77 Gr (5.56) - BC .42 - 2410 fps - 985 ft lbs - 1900 fps or less - 250 yds
Black Hills GMX 70 grain (5.56) BC. 350 - 2517 fps - 950 ft lbs - 2300 fps (*2000 fps) - *75 yds (Hornady claims a threshold of 2000 fps, but I have seen the 70 grain expand at 2300 but fail at 2200 fps)
Black Hills TSX 50 gr (5.56) - BC .197 - 2750 fps - 840 ft lbs - 2300 fps - 100 yds
Black Hills 77 grain MK262 mod 1 (5.56) BC .371 - 2420 fps - 985 ft lbs - 2200 fps *2148 - *75 yds (2200 is the Manufactures stated threshold but I have seen it expand lower from a HK 416 10.3 inch barrel with a impact velocity of 2148 fps)
Black Hills 69 grain SMK (5.56) - BC .317 - 2500 fps - 958 ft lbs - 2200 fps - 100 yds
Black Hills 68 grain OTM (5.56) - BC .350- 2500 fps - 958 ft lbs - 2200 fps - 125 yds
Barnes TSX 62 grain (5.56) - BC .286 - 2640 fps - 959 ft lbs - 2300 fps *(1800 fps) - * 150 yds *(Barnes claims expansion at 1800 fps,I have seen the TSX expand at 2300 fps but fail to expand at 2150)
Barnes TSX 70 gr (5.56) - BC .314 - 2550 fps - 1101 ft lbs - 2300 fps *(1800 fps) - * 75 yds (Same as above)
Speer GD 55 gr - BC .222 - 2620 fps - 826 ft lbs - 2000 fps (*1800 fps) - *150 yds *(2000 is the lowest expansion velocity I have seen but speer claims 1800)
Speer GD 64 gr - BC .25 - 2330 fps - 785 ft lbs - 1900 fps (*1800) - *150 yds ( Speer claims a expansion threshold of 1800 fps, but 1900 is the lowest I have observed with the 64 grain GD)
Hornady GMX 55 gr (5.56) - BC .27 - 2700 fps - 890 ft lbs - 2300 fps *(2000 fps) - *100 yds (Hornady claims a threshold of 2000 fps, but I have seen the 55 gr GMX expand at 2300 fps but fail at 2200 fps)
Hornady 75 grain TAP T2 (5.56) - BC .395 - 2400 fps - 959 ft lbs - 2200 fps - 100 yds
Nosler Bonded defense 64 grain BSB - BC .231 - 2300 - 752 ft lbs - 1800 fps (*1600 fps) - *150 yds *(Nosler list the threshold at 1600 fps, but I cant confirm less then 1800 fps )
Winchester Ranger 64 gr BSB RA556B (5.56) - BC .231 - 2550 fps - 924 ft lbs - 1800 - (*1600 fps) -*225 yds - (Same bullet as Nosler bonded defense, but loaded at 5.56 pressures)
Federal MK 318 sost 62 gr (5.56) - BC .307 - 2600 fps - 931 ft lbs - 2200 fps (*2000) - *150 yds *(2000 fps is a commonly given expansion threshold for the MK 318 but I cant find tests confirming under 2200)
*(5.56) = data is for ammo loaded to 5.56 pressures...
BC= Ballistic coefficient
**(all the data listed is for a 10.5 inch barrel)**
If using a 7.5 inch, typically they have about 300 fps less then a 10.5 inch barrel using the same round so you can subtract 300 fps from the ones listed and use a ballistics calculator to find a estimated range the threshold will be with a 7.5 inch barrel.
I tried to include expansion thresholds I have seen in tests along with the manufactures claims that I have received. If there was a difference between the manufactures claims and the test results I made a notation of that in parenthesis to the right of the list.
With the distances listed for approx. expansion range, Some rounds are probably capable at longer ranges if the expansion thresholds according to the manufacture is correct, but whenever possible I listed the expansion range using the lowest impact velocity I can confirm from gel tests and using a ballistic calculator to determine what range that would be with the muzzle velocity from a 10.5 inch barrel...
Basically, to err on the side of caution, I used the higher of the two and I listed the range as the distance testing shows they are capable of expanding reliably vs the distance they "might" expand at if the manufactures claims are correct. The exception being the MK262 77 grain SMK OTM mod 1 loaded by Black hills, in that case the lowest deformation velocity I found was lower then that given by the manufacture, but I still used the higher of the two figures when calculating the range for expansion.
I hope it is of help....
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This should be a big help to some folks, myself included...
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