Posts Tagged ‘break-in’

Apr
21

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.

Apr
21

How to Clean your Sig 556 Barrel

Following is the standard barrel cleaning process I use.

For starters, always use a quality one-piece cleaning rod from the likes of Bore-Tech, Dewey or Tipton. Also, use a vise or cleaning stand. I use Bore-Tech’s Eliminator on my centerfire rifles, and following the instructions that Bore-Tech provides yields excellent results.

It’s very simple:
Run 3-5 patches saturated with Eliminator through the barrel.
Run a nylon brush soaked with Eliminator through the barrel about 15 times.
Repeat step one – 3-5 wet patches.
Let soak 5-10 minutes.
Run dry patches through the barrel until they come out clean.

I recently broke in the barrel of my new Sig 556. There’s a LOT of cleaning that goes on in that process, so I put together a quick video of how to clean the Sig 556 barrel during break-in:

Apr
1

New Barrel Break-In Procedure

I’ve put off writing about this subject because there’s a ton of theories out there that all fly in different directions, and people get very touchy about their methods. So what I’m going to do is tell you what works for me. Do not consider this gospel, follow my guidelines at your own risk, etc.

Also, you’ll see instructions below to “clean.” Now, when I say “clean,” I don’t mean beat the crap out of the bore with a wire brush – I mean use a good, appropriate solvent, a bore guide, a one-piece coated rod (Bore Tech, Dewey, or Tipton CF), flannel patches and a nylon brush. I like Bore Tech cleaning products (Eliminator for centerfire and Rimfire Blend for rimfires), but many other solvents out there will equal Bore Tech’s.

When I clean a barrel with Eliminator or RfB, Bore Tech’s instructions work quite well: a few wet patches, brush, a few more wet patches, soak, then dry patches until they come out clean.

That said, I basically have two different procedures for basically two different types of barrels: factory production and custom hand-lapped.  We’ll start with the latter, because it’s really easy.

When you get a new firearm that has a custom hand-lapped barrel (like Krieger, WOA, Hart, Lilja, etc.), most of the work is done for you already. All there really is to do is some minor break-in, and that process is simple:

  1. Clean
  2. Fire one shot, clean (repeat 3 times)
  3. Fire three shots, clean
  4. Fire five shots, clean

And you’re done.

Now, with a factory barrel, you’ll find that the throat will be quite a bit rougher than a hand-lapped barrel. My procedure for a factory barrel is similar to the above, albeit a longer process, and I also incorporate an abrasive cleaner like JB bore paste. This is the procedure I use on my Rock River and other AR-15’s, Sig 556, Savage rifles… basically any rifle without a high-end lapped barrel.

Break-in procedure for factory barrels:

  1. Clean.
  2. Work the first 4-5 inches of barrel from breech with a small amount of JB bore paste on a patch, back and forth 10-15 times.
  3. Repeat steps 1 and 2 two more times.
  4. Clean.
  5. Fire one shot, clean. (repeat 5 times for SS barrel, 10-15 times for Chrome-Moly barrels)
  6. Fire three shots, clean. (repeat 3 times for Chrome barrel)
  7. Fire five shots, clean.

Now repeat that whole process until copper fouling is minimized – usually about 3 times on a centerfire rifle, 5 times on a rimfire rifle.

Tedious, isn’t it?

There is an alternative that works quite well: fire-lapping kits. These are just bullets with abrasive coatings that polish the throat and bore. I like Tubb’s Final Finish system. I won’t go into how to use it – just follow the his instructions… it works wonders.

As always with these kinds of things, your results may vary, try at your own risk, etc., etc.

Here are some other handy references if you want to learn more about the barrel manufacturing process and break-in – you should listen closer to the recommendations from the manufacturer of your barrel than me:
Krieger process
Lija process
Hart recommendations (see, they say no abrasives and no break-in necessary!)
Tubb’s fire-lapping info