Author
Message
JIM762
Offline
Posts: 1423
Feedback: 100% (26)
Posted: 11/27/2009 12:03:08 PM
Anybody Try Silver State Armory's 5.56 77 Gr. Ammo?
Molon
All hail Jeanne Assam!
Offline
Posts: 5345
Feedback: 100% (288)
Link To This Post
Posted: 11/27/2009 12:14:00 PM
Silver State Armory 77 grain OTM




Silver State Armory is now producing a 5.56mm NATO pressure, 77 grain OTM load with velocities on par with the Black Hills MK262 load. This makes SSA the fourth commercial ammunition manufacturer to currently offer a 5.56mm heavy OTM round loaded to NATO pressure; the other three being Black Hills (MK262), Hornady (5.56 TAP) and HSM (5.56-17T).

The SSA 77 grain load comes in simple brown boxes with nothing more than a “5.56” designation on it to give you a clue as to what’s inside the box. There is no indication of the bullet weight found anywhere on the box. This round is loaded with a 77 grain Sierra MatchKing without a cannelure.






The cartridge is charged with ball powder. The primers are crimped in place, although some of the crimps are so shallow that I needed magnification to see them. The primers are not sealed. As mentioned, the bullet does not have a cannelure, but there does appear to be a slight taper crimp on the case mouth that leaves a small indentation on the bullet. There is no sealant at the case mouth.



















The SSA 77 grain load was chronographed using an Oehler 35-P chronograph with “proof screen” technology. All velocities listed are muzzle velocities, as calculated from instrumental velocities using Oehler’s Ballistic Explorer software program. All strings of fire consisted of 10 shots each. Colt barrels in the lengths of 20”, 16” and 14.5’ were used as the test vehicles. All barrels used were chrome lined, NATO chambered and have 1:7” twists. Atmospheric conditions were recorded using a Kestrel 4000.


Temperature: 74 degrees F
Humidity: 58%
Barometric pressure:30.15 in Hg
Elevation: 950 feet above sea level


















The SSA 77 grain cartridges had a nominal length of approximately 2.250”. All rounds used in this test session fed, fired, extracted and ejected without any malfunctions. There was definite primer flattening noted on the fired caseheads, but no significant ejector or extractor brass flow marks.









Finally, here’s the data!








At one point during the test session I noticed an unexpected visitor on the range. The big guy pictured below was sitting on the berm about 10 feet above the target frame watching me.








Accuracy Report


Following my usual procedures, an accuracy evaluation of the Silver State Armory 77 grain OTM NATO load was conducted shooting from a concrete bench at a distance of 100 yards. The test vehicle used for this evaluation was a Noveske barreled RECCE. The 16” Noveske Recon barrel is made of stainless steel and has the 5.56 Noveske Match Mod 0 chamber, a 1:7" twist and polygonal rifling. The barrel is free-floated in a LaRue Tactical railed handguard.














The fore-end of the RECCE was rested in a Sinclair Windage Bench Rest with the aid of a modified Sinclair fore-end stabilizer. The butt-stock was stabilized in a Protektor bunny-ear bag. Sighting was accomplished using a Leupold VARI-X III with a mirage shade attached. Magnification was set at 25X and the scope was adjusted to be parallax free at 100 yards. The lower receiver used during testing has a Geissele match rifle trigger in it.















Atmospheric conditions were recorded on a Kestrel 4000. Skies were sunny and the winds were breezy. Wind conditions were continuously monitored using a Wind Probe which was positioned approximately 33 yards from the muzzle.


Temperature: 77 degrees F
Humidity: 51%
Barometric pressure: 29.87 inHg
Elevation: 950 feet above sea level















Prior to firing the SSA 77 grain load, I fired a 10-shot control group from 100 yards using a hot hand-load seated with Sierra 77 grain MatchKings (the same bullet used in the SSA load). That group had an extreme spread of 0.97”.









Three 10-shot groups of the SSA 77 grain OTM NATO load were fired from 100 yards using the described set-up. Those groups had extreme spreads of:

1.92”
1.60”
2.03”

for an average extreme spread of 1.85”. Those three groups were over-layed on each other using RSI Shooting Lab to form a 30-shot composite group. The mean radius of the composite group was 0.54”.

For comparison, three 10-shot groups of Hornady’s 75 grain 5.56 TAP previously fired from the same Noveske barrel had extreme spreads of:

1.03”
1.42”
1.20”

for an average extreme spread of 1.22”. The 30-shot composite group formed by over-laying those three groups on each other had a mean radius of 0.37”. The composite groups of the two different loads are shown below for visual comparison.









Lastly, for the Internet Commandos in our viewing audience I fired a 3-shot group of the SSA 77 grain load from 100 yards. That group had an extreme spread of 0.80”.






Member of the General Population
ops144
Offline
Posts: 1942
Feedback: 0% (0)
Link To This Post
Posted: 11/27/2009 4:19:39 PM
i guess that is a yes.
dano357
Offline
Posts: 168
Feedback: 100% (11)
Link To This Post
Posted: 11/27/2009 5:21:13 PM
nice write up Molon
ANIMUS
Offline
Posts: 4053
Feedback: 0% (0)
Link To This Post
Posted: 11/27/2009 9:25:00 PM
The current stuff uses the cannelured bullet and LC brass. Good stuff.
Instructor25
Member
Offline
Posts: 135
Feedback: 100% (139)
Link To This Post
Posted: 11/28/2009 12:33:18 AM
Well I would love to give a comprehensive report like MOLON, however I dont have many of the tools he has. Although I will give you an off hand answer from a weekend shooter. I shot some M855 this weekend along with some black hills seconds and some SSA 77's. I was using a 20' barrel with a 1/7 twist and breaking in the rifle on a hundred yard range. Here are my rough estimates. M855 group was was around 4.25 spread, black hills was around 2.50 and the SSa's were just under 2 with three rounds touching (5 shot group). Keep in mind that some of this was due to the shooter (me) calling some flier's (gotta get used to the two-stage trigger) and the barrel breaking in as well. Hope this helps, since Cabela's had this ammo on sale a few weeks ago.
cowboy7242001
The Myth
Online
Posts: 9620
Feedback: 100% (65)
Link To This Post
Posted: 11/28/2009 12:45:54 AM
I've ran through 1000 rounds in the past year or so, most of that being in the past 6 months.

~2MOA results out of my SPR, which normally does .75MOA with mk262. Lots of popped primers as well.

I went from very excited to dissappointed with my batch. The only good thing I can say about it is that the POI is very similar to mk262 and TAP on my guns, so I could use it effictivly as very pricey plinking rounds.
You can either use the best, or you can make up horse shit excuses about it and whine on the internet.
BB223
Offline
Posts: 1139
Feedback: 100% (4)
Link To This Post
Posted: 11/28/2009 4:50:48 AM
Roughly 1 in 5 cases has significant dents in them.

$1 a round for dented cases.

Awesome