Posts Tagged ‘5.56’


Sig Sauer Sig556

This is the Sig 556. This fine combat rifle is chambered in 5.56mm NATO, which can fire both the military 5.56 and .223 ammunition.

Sig 556 Rifle

Sig 556 Rifle

The barrel has a twist rate of 1:7, which is good for stabilizing bullets from 55 grain up to 75 grain. The Sig 556 uses a gas piston system, which keeps internals much cleaner and is arguably more reliable than the direct impingement system of an AR-15.

The stock is collapsable and folding. The buttstock tube will accept any AR-15 stock built for a commercial tube, so I replaced the stock Sig buttstock with a Magpul CTR.

Sig 556 with folding and collapsable Magpul CTR buttstock

Sig 556 with folding and collapsable Magpul CTR buttstock

The front iron sight is stout and hooded. The rear is a flimsy popsicle-stick popup sight that is practically useless. The front sight mount is different from the AR-15, so you cannot use a standard AR rear BUIS. One must either use a Sig-specific rear BUIS, or replace the front sight with one that is compatible with AR-15 rears (like a Samson). I have a Samson folding front sight and a Matech AR-15 rear BUIS on order.

The Sig 556 has a stout hooded front sight

The Sig 556 has a stout hooded front sight

The intended use for this Sig 556 is close to mid-range combat, so I decided to go with a 1-4 power scope from Millet. I’ll do a separate review of the scope later – for now, let’s just say I’m very happy with my choice.

A Millett DMS 1-4x24 scope tops the Sig 556

A Millett DMS 1-4x24 scope tops the Sig 556

One of the best things about this rifle is its factory two-stage trigger. This is by far the best factory trigger I’ve ever seen on any AR-style rifle. The Sig 556 trigger is clean, crisp and light. It’s not as nice as some aftermarket triggers like Timney, but it is an excellent factory trigger.

Now, I’ve heard from many, many sources on the interwebs that the Sig 556 isn’t all that accurate, with reported groups of 2-4″ at 100 yards. While such groups are acceptable for a close-quarters combat rifle, I suspected that the shooters of these reported groups didn’t share my zest for accuracy.

So my quest begins…

I performed my standard barrel break-in procedure on this rifle. If you’d like the short version, it’s like this:

  • Clean
  • JB bore paste, Clean. (repeat)
  • Fire one shot, Clean (repeat 5 times)
  • Fire 3 shots, Clean (repeat 3 times)
  • Fire 5 shots, Clean

After the barrel was broken in, I fired two 10-shot groups of 55gr VMAX to get a rough zero on the scope and foul the barrel. I then switched to some 69gr Black Hills HPBT match ammo and fired a few:

Not too shabby!

I shot some 3-shot groups that were under 1/2″, but I still think this black rifle can get tighter. Next steps for this rifle will be more shooting and cleaning, accompanied by a run-through with Tubb’s Final Finish system.

Until next time, Happy Shooting.


Articles Inbound!

Some new gear is in, and a bunch of ammo is on its way. We’re going to have some exciting articles in the next coming weeks.

First, we have a brand new Sig 556 to break in. We’ll walk through the process of breaking in a new factory production barrel (much different from a hand lapped barrel like White Oak or Kreiger makes).

The Sig 556 barrel has a 1:7 twist, which is well-suited for heavier .223/5.56 bullets. We have a few varieties of match ammunition from 62gr-75gr that we’re going to run through the Sig to see what she likes.

We’ll also be looking at the HK USP 9mm compact as a carry weapon, and seeing how accurate this factory pistol can be with 8 varieties of 124gr 9mm ammo.

Match .22 LR ammo is inbound for a rimfire shootout! The Savage Mark II BTVS is one accurate bolt-action rifle, and we’ll have several varieties of match ammunition from Eley, Lapua, SK, RWS and Wolf to send down-range.

And last but not least, a new Shooting Chrony F-1 is on its way. This will not only help us understand more about the ballistics of what we’re shooting, but it will help us isolate ammunition issues and give us a feel for the consistency and quality of the ammo we’re testing.

Happy shooting.


Range Report: RRA AR-15 Pistol

Finally had some time to process some video. Here’s a quick highlight reel of the RRA Pistol testing:

You can see the different groups at 25 and 50 yards. This is firing with the EOTech and a variety of good .223. Since this is primarily a sub-50-yard weapon, I’m calling this acceptable accuracy.

RRA AR-15 Pistol 5-shot Group

RRA AR-15 Pistol 5-shot Group

Down the road, I’ll mount the Leupold Mark AR on it just to see what the short barrel is capable of at longer distances.


Rock River Arms AR-15 Pistol

Meet the RRA LAR-15 A4 Pistol.

Rock River Arms LAR-15

Rock River Arms LAR-15

This particular pistol is chambered in 5.56 NATO. It has a 7″ Chrome Moly 1:9 twist barrel on a flat-top upper with a free-float tube. This came from the Rock River Arms factory with a Hogue grip and RRA’s Dominator2 EOTech mount.

Rock River Arms LAR-15

Rock River Arms LAR-15

The Dominator2 allows co-witness of the iron sights with an EOTech holographic weapons sight. Seems like a good chance to try out the EOTech 551.

Rock River Arms LAR-15

Rock River Arms LAR-15 with EOTech 551

This one is still pretty new to me. I’ve performed the barrel break-in and I’ve zeroed the iron sights and the EOTech, but that’s about all. We’ll run it through its paces as soon as we’re blessed with some decent weather.

Happy shooting.


Rock River Arms Mid-Length A4

Here’s one of the rifles you’ll be reading a lot about on this site. Meet the Rock River Arms mid-length A4…

Rock River Arms mid-length A4

Rock River Arms mid-length A4 - barrel view

From the factory, this fine AR-15 rifle features a 16″ chrome-moly barrel with a 1:9 twist, flat-top upper, standard mid-length handguards, a 6-position collapsible stock, and RRA’s standard heavy trigger.

In the photo above, you can see that we’ve already made a few changes to it. The standard handguards have been replaced with a two-piece picatinny rail system from Midwest Industries. A mil-spec buffer tube has been installed, as well as a Magupl MOE stock. We’ve also outfitted this rifle with a Surefire M900A vertical foregrip weapon light.

What we really want to do is see how well this gun can shoot. To facilitate that effort, we start by modifying the AR-15 to help the shooter fire it more accurately.

First is a Timney Trigger set to a 3-pound pull.

Timney Trigger on RRA AR-15

Timney Trigger on RRA AR-15

Next, in order to eliminate our human error as much as possible, we install a Leupold Mark AR 3-9×40 scope on Burris Xtreme Tactical rings.

Leupold Mark AR 3-9x40 with Burris Xtreme rings

More on the barrel break-in, cleaning, and firing of this fine weapon is to come.

Happy shooting.