Sig Elite 5.56 NATO 77 grain chrono results

[gunmike1]

I have been very happy with the accuracy of Sig Elite Performance 5.56 NATO 77 grain ammo for a while. It consistently shoots 1/2 MOA or better from my 18” Daniel Defense DDM4 V7 Pro, though we are talking 3 shot groups instead of the normal 5 since the ammo is hard to come by. When I finally got a Magnetospeed it clocked in at 2849 FPS. That seemed like it was possibly an error, as that is higher than I would expect from Black Hills Mk 262. The Copper Creek 77 grain clocked in at 2433 FPS that same day, which is similar to the chro results I saw online for Sig’s 223 77 grain load, so it seemed the chrono was working right, but I still had my doubts. I went back out and clocked the Sig 5.56 ammo on my new labradar this weekend and it come in at 2843 FPS, so it appears 100% legit on the velocity. I pulled a bullet just to verify the bullet weight was correct, and it weighed in right at 77.0 grains, and has about 26 grains of powder behind it.

Has anyone else ran a chrono on Sig Elite Performance 5.56 NATO 77 grain ammo? I bought about 15 boxes from Sportsmans Warehouse a while ago, and mine are in a white box that differs from what I am now seeing on Sig’s website. I have 10 more boxes coming from a different vendor, and I will chrono those to see how they compare. I’m just surprised that I’m seeing velocity almost 100 FPS above the rated 2750 FPS, and higher than I remember seeing for Black Hills Mk 262 out of an 18” barrel. I didn’t buy this stuff trying to get crazy velocities, I just wanted to get good groups and was hoping to be a higher velocity than the 2400-2500 that I’ve seen posted online for many 77 grain 5.56 loads.

 

[celltech]

IMI 77gr clocked 2810+ in my 18" as well...so that is in the ballpark. But it sure was some hot stuff...

 

[Bigjake83]

I haven't ran any Sig .223 Match yet, but the .308 shoot amazingly well in both my custom Large Frame .308 AR's one with a Craddock Bartlein and the other with a CLE Bartlein and they both seem to out perform FGMM in accuracy and MZ.

I don't have the MZ at hand but I know it was damn close to 2500FPS out of 18" barrels and easy 1/2 MOA

 

[atomic41]

I haven't shot it but that seems hot for an 18" and as you stated sig rates it at 2750. Just curious, is the test barrel length on the box? Surely your 18" is shorter than their test barrel and you are still 100 over, something is not right.

 

[gunmike1]

I haven't shot it but that seems hot for an 18" and as you stated sig rates it at 2750. Just curious, is the test barrel length on the box? Surely your 18" is shorter than their test barrel and you are still 100 over, something is not right.

It only says 2750 FPS on it, and nothing about the barrel length. I’ve read that Black Hills rates their Mk 262 as 2750 out of a 20” barrel, and I was assuming Sig did the same. I guess I can always reach out to Sig to get the length of barrel they rate the ammo at. From an article I read that did a comparison between Black Hills Mk 262 and Sig 223 (not 5.56 like I am using) 77 grain ammo the Sig was way behind the Black Hills in the 2430-2450 FPS range, but Sig rated that ammo at the same 2750 FPS. They must be quoting that velocity out of a 24” bolt gun to be 300 FPS below their rates velocity from an AR.

 

[gunmike1]

I haven't ran any Sig .223 Match yet, but the .308 shoot amazingly well in both my custom Large Frame .308 AR's one with a Craddock Bartlein and the other with a CLE Bartlein and they both seem to out perform FGMM in accuracy and MZ.

I don't have the MZ at hand but I know it was damn close to 2500FPS out of 18" barrels and easy 1/2 MOA

I’ve been very happy with the accuracy of my Sig 5.56 ammo, and I plan to try out their 308 match ammo. FGMM 175 grain averages a little under 3/4 MOA from my POF Revolution DI, and I will see if the Sig ammo can improve on that.

 

[bfoosh006]

How hot was it when you were firing the ammo ? Was the ammo maybe sitting in the sun ?

Just curious.

And those speeds are high, even for a 5.56 load.

 

[TheOE800]

IMI 77gr clocked 2810+ in my 18" as well...so that is in the ballpark. But it sure was some hot stuff...

That’s my experience in summer ambient temperatures as well.

 

[deersniper]

Did I miss the ES and SD

 

[gunmike1]

How hot was it when you were firing the ammo ? Was the ammo maybe sitting in the sun ?

Just curious.

And those speeds are high, even for a 5.56 load.

I started shooting this in the morning, ammo was in my bag in the shade, ambient temp around 60 degrees at that time when I tested it Sunday. The first time I tested it was probably late morning, ambient temp maybe 65-70, ammo was not sitting out as it was the first thing I shot when I got to the range. So I’m not seeing the temp as a major factor on getting near 2850 FPS. No primers have fallen out, but the primers have lost some roundness. I’ll have to compare the primers to some fired Green Tip rounds next time I shoot. I got 2988 FPS when I chrono checked them next to the Sig 77 grain, which seems about right from an 18” barrel.

 

[gunmike1]

Did I miss the ES and SD

You did not, I forgot to post them. I got 16.1 SD and 41 ES from 10 shots of the Sig 77 grain.