Got out to test my new build. This rifle is a 'budget-ish' build with an Anderson lower (registered SBR) and upper, LWRC UCIW stock, 8" 1:7 CMMG .300 BLK Nitride barrel (pistol length gas), CMMG RKM7 free float handguard with a BCM low profile gas block. The suppressor is a SiCo Omega with the 5/8X24 direct thread module and 7.62 flat cap attached.

All velocity testing was done with a Master Chrony at 12 feet from the muzzle and all shots were taken off a Lead Sled with the rifle locked down.

This is my first "complete" build where I bought every part individually and assembled it myself, upper and lower. I've built plenty of lowers over the years and just slapped a complete upper on them though. I'm happy to report that there wasn't a single malfunction firing 13 different factory loads and there was virtually zero gas to the face shooting this rifle suppressed.

Here's the rifle as configured for the test (Leupold Mark AR 3-9X40 & Geissele SSA-E):



And here it is in its regular 'everyday' configuration (Trijicon MRO...The Geissele is still in it for this picture but it will have an ALG ACT in it):



The ammo used for the tests:



The weather:
Air Temp: 48 degrees
Humidity: 54%
Dewpoint: 30 degrees
Pressure: 29.89

The Results:

Supersonic

Barnes 110gr TAC-TX
2097     ES 29 FPS
2113             AVG 2112 FPS
2113
2118
2118
2107
2126
2120
2099
2106



Barnes 120gr TAC-TX
1889 ES 86 FPS
1878 AVG 1870 FPS
1892
1863
1900
1860
1856
1814
1860
1889



Black Hills 125gr TMK
1970 ES 44 FPS
1953 AVG 1950 FPS
1926
1938
1956
1955
1942
1943
1969
1948



Nosler 125gr BT
1888   ES 69 FPS
1875 AVG 1864 FPS
1856
1834
1819
1856
1873
1869
1878
1887



HSM 125gr Sierra SPT
2050 ES 57 FPS
2042 AVG 2035 FPS
2037
2063
2041
2016
2006
2052
2031
2007



Hornady 110gr VMAX
2158 ES 66 FPS
2092 AVG 2124 FPS
2142
2100
2119
2122
2118
2105
2146
2135



PNW 'Range' 147gr FMJ
1754 ES 45 FPS
1761 AVG 1745 FPS
1755
1774
1753
1672
1754
1749
1753
1729



Sellier & Bellot 124gr FMJ
1783 ES 62 FPS
1783 AVG 1793 FPS
1797
1818
1820
1788
1796
1789
1798
1758



Sellier & Bellot 147gr FMJ
1833 ES 33 FPS
1823 AVG 1824 FPS
1847
1835
1814
1820
1818
1821
1813
1819

Subsonic

Subsonic tests were done at both 50 and 100 yds. Only 5 rounds were tested at 50 yds.

Remington 220gr OTM
972 ES 53 FPS
963 AVG 992 FPS
993
994
996
1007
975
1003
1016
1005

 

Remington UMC 220gr OT FB
1004 ES 55 FPS
978 AVG 973 FPS
989
971
975
968
949
973
968
952



Federal 220gr OTM 'Suppressor'
1021 ES 42 FPS
998 AVG 1010 FPS
1015
1030
994
1013
988
1017
1020
1005



Hornady 208gr AMAX
1016 ES 34 FPS
1007 AVG 1017 FPS
1019
1007
1020
1021
1008
1015
1012
1041

Awesome!  Thank for another great thread.  I'm waiting on the Sig MCX adaptor kit and their 300 bo upper.  Should make a great backpack gun with the folding stock.
 


Looks looks like the 110g tsx is still quite potent in that barrel length.


 

Thanks! My two favorites loads so far are the 110 TAC-TX for supersonic and 208 AMAX for subsonic. Honorable mention for the 125 TMK. I generally LOVE TMK/SMK bullets and Black Hills ammo so it was nice to see that combo perform well in another platform.

I'm a little baffled about the 120 TAC-TX accuracy though. Could just be this particular barrel/ammo combo but I think it warrants another test.

An informative and thorough test. Thank you!

was that Omega the FDE version sold by Silencer shop? That cerakote doesn't seem to hold up very well.

Yes, it is an FDE Omega bought from Silencershop last summer and approved in late October. Every suppressor will discolor if you get it hot enough. This particular one had 3 mag dumps done with 5.56 in about a 10 minute timeframe and that's when I noticed the discoloration starting get to the point it's at.

I haven't gotten it quite that hot since but I wouldn't be scared to do it again.

Quick side note or anecdotal observation on the .300 BLK cartridge...

This is my first .300 BLK gun and I shot ~150 rounds total yesterday. I cleaned it today and it had more carbon buildup/crud than any other AR in my stable, by far, including 5.56 SBR's that are only fired suppressed. Just an FYI to anyone thinking about running one of these suppressed all the time, make sure you do the proper maintenance!

Nice work!

i found the groups of PNW 147 to be unsatisfactory as well, virtually double+ what the black tips shot. thats was eyeballin' no fancy rulers.

this out of an 8.5" RA ultra match

thx for the work.

.

Thanks Molon! Means a lot coming from you

I do the best I can but don't have quite the drive (or equipment) you do to make them as perfect as yours are. What I believe this test did was show some popular and budget .300 BLK options with as many variables as possible accounted for with my equipment.



Yep, that PNW sure performed craptastically. I won't be buying any more of that. Even at .$50/round it's just not worth it. I get buckshot groups better than that

Thanks for sharing your experience with it as well!

"Thanks Molon! Means a lot coming from you

I do the best I can but don't have quite the drive (or equipment) you do to make them as perfect as yours are. What I believe this test did was show some popular and budget .300 BLK options with as many variables as possible accounted for with my equipment."


Agree...well done.
I just read Molons last work, and asked if he has done any 300 Blk work, and then found this!

Thank you for your time, expense, and effort.

eta...Sorry for the butcher job on the quotes
I added some of these "..."
Again, well done

Good stuff, thanks!

Another one to add would be the PNW 220gr subsonic.  It did very well out of my Ruger American 300BO, haven't tried it in an AR yet.