I had previously run a couple of hundred rounds of cheap 7.62 through the rifle to break in and then sighted it in with 175 grain Federal Premium ammo.
Put in a SSA-E trigger and brought back out and I could not get any kind of grouping with either Federal or Winchester 7.62 ammo.
Checked with the 175 premium and holes were touching, so my question- Is the 7.62 ammo that bad or does the 716 not like the 147 grain bullet weight?
Groups were up to eight inches with the 7.62 stuff this was using a Vortex PST 6-24x scope in a Larue mount.

ETA, the shooting was the same session, some 7.62 to get a feel for the new trigger before the near $2 a pop premium stuff, scope was tight and shooting was off a sandbag rest.
It appears the ammo is the issue so I will try some S&B, I will gladly settle for ~2 MOA groups, I could at least hit the 300 yard gong!

8" sounds kinda like something was wrong with either the ammo, the gun or the shooter. Were both ammos shot in the same day?

is your mount solid?  if even a little loose, not detectable unless you grab it and try to move it around you are going to be all over the place.  Thats the simplest and easiest place to start if you haven't already.

Mine did almost as bad as yours with the 7.62 147 ZQI. Switched to a mag of .308 TSX, then AMAX, then 150 American Eagle boat tail. All decent groups. Switched to a mag again of the 7.62 147 this time a Fed load and it was more of the 4-6 inch groups. The PMC is almost as bad.

My 716 shoots S&B NATO very well, and shoots ZQI NATO so bad, you might as well be underhand throwing a handful of pink gravel at the target from 20 yards.

I have not had good luck with the white box winchester 7.62 in several rifles, including a Rem 700 bolt gun.  I have ran DAG through my 716 and groups were respectable but not as good as my reloads.

I was frustrated after my first trip to the range with only 147gr. NATO rounds (PMC, ZQ1) but was very happy after doing some research and realizing it's not just me. My second trip out yielded results similar to what the OP reported. The 147gr. NATO stuff make 4-6" groups at 100; Federal American Eagle 150gr 2-3" groups, and Hornady SST 165gr. shoots under 1 MOA. Bottom line is a 4-6" group at 100 equates to a neutralized threat yet the rifle is accurate enough to be a very good coyote rifle at 600. I love mine now that SIG fixed the fail to eject issue and it runs flawlessly no matter what I throw at it.

I wont be running 147-149gr ball through my DMR because its mild steel jacket not copper. That's why its magnetic.

My 716 had horrible 10" groups at 100 yards right out of the box shooting PPU ammo.    Long story short, after 400 rounds, the rifle has had a sufficient break in period to shoot much better groups now, even with the cheaper ammo.   On the other hand, just got a SCAR17 and it shoots better than my 716 without the need for this break-in stuff.  

My three 716s all shot 1MOA using Barnes 130 grain TSX handloads all day long with Gemtech Sandstorm suppressors.





250 yard coyotes/hogs are not a problem.

The 716 is reported to have a chrome lined bore and chamber so no barrel "break in " will have a dramatic effect.
(The SCAR has the same type of barrel)

Garbage in = Garbage out
My 716 does MOA easily with good ammo and military ball  (NATO Portuguese) does 2~3 MOA on average.

Using Federal 168gr Sierra Match I was pulling about 2" at 200 yards today.  147 Grain PMC (?) was about 10".  It seems to like heavier rounds.  This thing is going to make me start hand loading.

I don't know about other rifles, but ZQI was all over the map in my 716. I gave the rest of what I had away.