Originally Posted By Recusance:
I was thinking of buying a 556P and adding a butt stock (after stamp)......is that possible?
or buying a folding stock gun and having a 10.5 barrel installed (after stamp)
You've got 3 options to get a ~10.5" barrel'd SIG556:
Option 1:
Buy a Sig 556P, install buttstock. Yes, this is possible, it's the route I'm taking. Only downside is that the pistol lower is the "original" style that has an accommodation in the rear for an AR buffer tube, rather than the classic "swiss" style stock. If you wanted a "swiss" aka "classic" stock, you'll need to trade lowers with someone.
Option 2:
Buy a Patrol, have the barrel cut down. The Patrol has the correct length gas system, but I do not know if there are any port size modifications that need to be made. I suppose you could also install a pistol barrel, but for what Adco would charge for a cut and crown, not sure it's worth it.
Option 3:
SIG Factory 556 SBR. I know these exist, beyond that, I know nothing.
Option 1 is definitely the "easy button" but some people don't like it because the receiver is engraved with "FOR PISTOL USE ONLY HERPYDERP". I didn't really care, but in some states it might actually make a difference.
I went option 3 but it's in the process of transferring at my sot. I thought about doing the pistol version but after the rails and lower that's on my swat didn't think it was worth it. Plus you have to get the upper receiver engraved since it's the registered part and going a factory sbr is much cleaner.
I went with option 3 also. Great gun.
Originally Posted By smb980:
What is the price range of option 3?
$1,650-$2,300 from what I've seen (for the exact same model).
Originally Posted By smb980:
What is the price range of option 3?
It depends on the model. Sig makes 2 models of their SBR rifles. Mine is the 556405. I can't give a fair price as mine came from an LE supplier and I got it new, pretty cheap.
Something else to consider... If you go with either #1 or #2 you void your SIG Lifetime Warranty the second you become the "manufacturer".
I went with option one, and have been very fortunate to have not had any problems with the weapon. There have been several threads over on SIG 556 forum where guys who SBR'd the 556P's had the top rail fall off the receiver or other such shit and SIG informed them the warranty was void. IIRC, SIG did tell them they could pay to have the repairs done at the factory. I spoke to my SIG LE rep who advised the same. With the lack of spare parts if something major breaks, you're screwed.
I replaced my factory airsoft quality top and quad rail with a Troy as the chances of ripping that thing off the receiver are slim and none and if it happens I'm probably FUBAR'd too.
If at all possible, go with option #3 and get a factory SBR.
I did not know that there were two different models of sig SBR's. Can you tell me what the differences are? What are the two model numbers? Thanks

Originally Posted By ralexander69:
I did not know that there were two different models of sig SBR's. Can you tell me what the differences are? What are the two model numbers? Thanks

Sig makes an SBR version of all of it's rifles. The 2 that I was speaking about are the Classic and Patrol SWAT. Sig also makes an SBR version of the 516 and shows a CQB version of their 716 in the catalog.
http://www.sigsauer.com/upFiles/CmsContent/documents/SIG_US2010LEMILweb_june21.pdf
Originally Posted By TxLawDog:
Originally Posted By ralexander69:
I did not know that there were two different models of sig SBR's. Can you tell me what the differences are? What are the two model numbers? Thanks

Sig makes an SBR version of all of it's rifles. The 2 that I was speaking about are the Classic and Patrol SWAT. Sig also makes an SBR version of the 516 and shows a CQB version of their 716 in the catalog.
http://www.sigsauer.com/upFiles/CmsContent/documents/SIG_US2010LEMILweb_june21.pdf
Thanks for the link. I'm liking the sig classic sbr and the shorty 716