WTS: SIG 556-to-551 barrel, Swiss 55X magazines, SE Vortex Ops Inc hider, C7/A1E2 upper, 552/3 HG
556-to-551 conversion barrel. Swiss 551 barrel with trunnion thread adapter to enable installation in a US 556 receiver. Will need completed by a gunsmith. Barrel comes with two-piece barrel extension as well, which enables a 16" length without any modification to the barrel itself. $350 shipped.
Used, "restricted" LE-marked, 20rd Swiss 55X mags. Three available. $95 shipped per mag, or $265 shipped for all three. All magazines will be inspected at known failure points before shipping.
Used, good condition. C7/A1E2 "A2 with field sights" upper. I've seen this configuration called a few things; I am not sure what is technically correct. It is not an actual Diemaco; it is marked with a D and a K. No M4 feed ramps. Fixed carry handle with A1 sight, forward assist, and brass deflector. $100 shipped.
Used Smith Enterprise Vortex flash hider 1/2x28 with external threads for Ops Inc Model 12 (AEM5/OCM5). $60 shipped.
Sig 552/553 Swiss SAN black plastic handguard. Used; like-new. $100 shipped.
Sig 55X upswept Swiss cocking handle. Used. Good condition. $75 shipped.
US Sig 556 "Patrol" recoil assembly. Brand new in the package PN: 1511879-R. This is the good, unfluted rod with flat wire spring. $150 shipped.
B&T Rotex flash hider for Sig 552/3. 14x1LH thread. $75 shipped.
Reproduction Sig 552 recoil springs. $40 each; shipped.
I also have some other unique and/or hard to find Sig 55X rifle parts. Let me know if there's something specific you're after.
Email for pictures or questions. Payment methods accepted are CC+4%, PPf+f, personal check, or USPS MO. Will not ship until a week after deposit of personal check. Additional shipping fees incurred for AK, HI, WA, CA, and OR.
Willing to cut a deal, for anyone buying multiple things.This message has been edited. Last edited by: KSGM,
September 09, 2022, 11:13 AM
KSGM
I have produced a small run of Sig SG551 silencer adapters. The adapters use a Halo-style collar and pocket attachment interface, and are compatible with silencers threaded in 1.375x24, otherwise known as “HUB”. The adapters are CNC machined from 17-4 stainless steel, and salt bath nitrided.
In the interest of transparency, I want to make potential purchasers aware of an idiosyncrasy:
The HUB threads on the adapters are on the small side; this means there is a bit of wiggle when you are screwing the adapter into the silencer; the play obviously disappears when the unit is completely tightened. This phenomenon is consistent across all units and all silencers I have threaded the adapters into, to varying degrees, depending on the silencer manufacturer's thread tolerances.
Q&A:
Q: Will the adapter work on a 550 or 551/3 LB?
A: No. Those weapons use one of two possible flash hiders of NATO dimensions. Depending on which flash hider your rifle has, there may already be silencer options available.
Q: Can you produce an adapter that will work on a 550 or 551/3 LB?
A: Yes. The same design can be modified slightly, and applied to a 550 silencer adapter. However, I don't intend to invest in a run of 550 adapters in the near future.
Q: Will this adapter work with my (insert make/model of silencer)?
A: Only if it is threaded 1.375x24 in the back. If the silencer manufacturer states their silencer is threaded “HUB”, 1.375x24, or 1 3/8 x 24, it will work.
Q: Will this adapter work on the 551 with the longer barrel without the grenade gasket?
A: No. This adapter is for a proper 551 only. Dimensions of the flash hider should be as follows: Diameter of flash hider not to exceed .845" Length of flash hider ~1.650" Length of flash hider including taper down to barrel diameter ~1.950" Barrel diameter behind flash hider not to exceed .570"
$140.00 shipped. Email for pictures or questions. Payment methods accepted are CC+4%, PPf+f, personal check, or USPS MO. Will not ship until a week after deposit of personal check. Additional shipping fees incurred for AK, HI, WA, CA, and OR.This message has been edited. Last edited by: KSGM,