SIG 556 Sniper/Accurized Project (Not DMR)

[FNP90]

So Ive always been a fan of the SIG 550 series and with the advent of the 556, customization is a bit more affordable. Ive liked the 550 sniper, but its a bit dated and I thought that I could do something a bit more modern. So heres my project, its nearly complete, once Im sure that its set-up properly, Ill repaint everything to match.

Ive been trying different loads and Ive been the most happy with Hornady TAP. Ive had several .55 to .8 5 shot groups at 100 yards with it so far, but Im still early in the load process.

The barrel is 18" Hart and so far it has operated flawlessly. An upside to being local to Hart is that they graciously decided to a do a one-of for me. They have asked me to not send people their way for the work unless I organized it to be done in lots of 10, so please respect their wishes there!

 

[sticshooter]

Re: SIG 556 Sniper/Accurized Project (Not DMR)

sweet,i love those sigs too

 

[GunKnowledge]

Re: SIG 556 Sniper/Accurized Project (Not DMR)

You went with the 551 lower???

PM sent about doing a group buy.

 

[RWSGunsmithing]

Re: SIG 556 Sniper/Accurized Project (Not DMR)

Very interesting. I would like to know more about your project like what you started with where you got the sniper stock and so on.

 

[FNP90]

Re: SIG 556 Sniper/Accurized Project (Not DMR)

Well, Ive had a few PM's about the barrel.

Ill see about putting together group buy, please PM me your contact info if youre interested and Ill see what kind of pricing I can get and let everyone know.

 

[leadbullet]

Re: SIG 556 Sniper/Accurized Project (Not DMR)

That is a beauty, very well done.

 

[cz777]

Re: SIG 556 Sniper/Accurized Project (Not DMR)

very nice work ! i had one early 556 that had the swiss made barrel in her --seen the proof marks plus a lot of other swiss made parts ..i got other parts but the lower was 556 not 550 ...she loved 75/77 grain match loads ....

 

[gstaylorg]

Re: SIG 556 Sniper/Accurized Project (Not DMR)

I've often thought of doing a project very similar to yours. Prior to returning to Kalifornia last August, I had 4 Sig 556 rifles in various flavors and two 556 pistols. I definitely liked the platform, but accuracy wasn't stellar, even with the DMR. Unfortunately, it was more trouble than it was worth to modify them to be Kalifornia-compliant, so I sold them before moving.

Can you elaborate on the exact mods you did, other than just the barrel? Clearly you installed a new buttstock and grip; anything else? What about the trigger? To me, the trigger was probably the greatest single impediment to accuracy in the whole platform. My 556 SWATs ran close to 8 lb pull and even the DMR was over 6 lb. FYI, there are a couple different places to get much improved trigger assemblies if you haven't done it already:

http://www.triggerwork.net/sig556.html

http://sigforum.com/eve/forums/a/tpc/f/630601935/m/2760069082

In any case, looks like you did a great job with it, and I hope you're enjoying it!

 

[CCCCanuck]

Re: SIG 556 Sniper/Accurized Project (Not DMR)

Show off...

But seriously, I've seen this thing in person and it is sah-weeet.

 

[wes1]

Re: SIG 556 Sniper/Accurized Project (Not DMR)

IM sent on barrel pricing

 

[fishdog]

Re: SIG 556 Sniper/Accurized Project (Not DMR)

very nice work. its nice to see a unique platform being built up like this

 

[Bedlam]

Re: SIG 556 Sniper/Accurized Project (Not DMR)

List your customizations dammit! Especially that stock!

What is the barrel twist? Stainless I assume?

There is a Sig556 barrel nut now, so you can free float the hand guards, but it sounds like you are getting great groups without free float.

 

[FNP90]

Re: SIG 556 Sniper/Accurized Project (Not DMR)

The base rifle is an early 556. The early 556's contained a majority of Swiss parts, and also have more welds mating the receiver shell stamping to the internal rails than the later models.

The rail is a SIGARMS Swat rail with the integral sight rail, this allows the pin that mates the rail to the gas block to be removed so that the rail "free floats" which is kind of a misnomer with a long strok piston, but it at least removes the bipod stress against the barrel. The rail is mated to the top of the receiver and the lower upper and lower receiver retention pin.

A custom gas tube was used to allow clearance over the heavy barrel. The barrel is an 18" stainless.

The lower is a Swiss 550/551/552 in safe and semi only. The stock and grip are mad by a German company specializing in SIG accessories. They are amazing pieces, but terribly expensive.

The hammer and sear are a ShootingSight product, which are impresive unto themselves. I do not have a pull gauge, but it is probably 6 lbs and will require some additional work. I will probably make an over travel stop as well. The SIG factory trigger is adjustable, this is adjusted so that a very slight pressure is required after the trigger contacts the plunger behind it.

The bipod is a Brugger and Thomet plastic copy of a Parker Hale. Its usable, but definitely not as sturdy as my Parker Hale but the weight tradeoff may well be worth it.

 

[jn_fsu]

Re: SIG 556 Sniper/Accurized Project (Not DMR)

Thats a sweet rig! Very nice job!

 

[Bedlam]

Re: SIG 556 Sniper/Accurized Project (Not DMR)

Awesome man, thanks for the details!

 

[FN in MT]

Re: SIG 556 Sniper/Accurized Project (Not DMR)

I know the Hart Boys very well. They hunt deer and elk just south of me. Look forward to them coming out to the Cabin each Fall to hunt. Nice group of guys, especially PJ.

They did a .257 Roberts AI for me on a pre 64 M-70, and a .280 Rem AI on a Rem 700. Both varmint gun accurate. They surely know how to build a rifle.

FN in MT