Some infor for you | Page 3 | SIG Sauer 556 Forum

Some infor for you

Discussion in '556 Discussions' started by Bosley, May 18, 2020.

  1. Bosley

    Bosley Active Member

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    lol, Notch Kings! lol.
    "Hey Lou, I got the barrel on, but the gas tube won't fit!".
    "Stand back," says the design engineer as he plugs in a 4 inch angle grinder, "I have a solution!".

    Weird that they marked the cup with the orifice size. Makes me wonder how many of these were produced and if you got one of the prototype ones.
     
  2. CGRBB

    CGRBB Active Member

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    I think I have one of these marked valves as well. I’ll check in a minute. What do we know about valves? I am fairly certain SAN never made one with a black finish, but I think Sig USA made them in both finishes.
     
  3. Yuns

    Yuns Member

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    The gas valve with the 1.2/1.3 markings is the Swiss valve. I think that may be standard these days for the Swiss 55x series. The US DMR one doesn't have size marked.
     
  4. Yuns

    Yuns Member

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    For reference here is the gas valve size chart: that I took from a prior thread. You'll notice that 2 types of steel are mentioned. Most is X39CrMo17-1 staiinless steel but the ones for the 550 and some for the 551 LB running GP90 are S 6-5-2 tool steel.

    [​IMG]
     
    Last edited: May 22, 2020 at 9:21 AM
  5. CGRBB

    CGRBB Active Member

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    Considering the issues I had with a 100% Swiss 553, I think that chart is to be taken with a grain of salt. Another thing I suspect is that (not chart-related) Sig USA used the same valves in the patrols and pistols as the 556 and 551A1. Anyone have any info on that?
     
  6. CGRBB

    CGRBB Active Member

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    I guess it bears mentioning that the problem I had was fixed by adjusting the size of the gas port in the valve, but not necessarily caused by it. The exact cause is not known.

    But something else I have real-world experience with is a SAN 4-position valve in both a 553 and 553LB. It isn’t ideal in either. I use it in the 553LB because it provides a port that is appropriate for use with a silencer, but without a silencer, none of the ports are quite right, and I’ll re-install the 2-POS valve.
     
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  7. Yuns

    Yuns Member

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    There is a thread in m4carbine where someone measured the actual sizes of his gas ports. I added the mm conversions.
    Sig556 Gas Valves - Page 2

    556 Classic valve (silver in color)
    Large hole: 0.053" (1.346mm)
    Small hole: 0.050" (1.27mm)

    Original 556 SBR valve (marked E opposite UP designation) [DMR is MARKED E]
    Large hole: 0.054" (1.372mm)
    Small hole: 0.051" (1.295mm)

    New valve from Sig USA packaging (marked A opposite UP designation)
    Both holes: Over 0.060" (1.524+mm)

    New valve from Sig USA packaging (no letter designation opposite UP designation)
    Large hole: 0.049" (1.245mm)
    Small hole: 0.047" (1.194mm)

    553R LB valve (marked 12 13 14 15 on face)
    Largest hole (15) : 0.058" (1.473mm)
    Next hole (14) : 0.053" (1.346mm)
    Next hole (13) : 0.050" (1.27mm)
    Smallest hole (12): 0.046" (1.168mm)
     
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  8. CGRBB

    CGRBB Active Member

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    I have a couple marked with a B opposite the UP. Also, the one on the end is a 552 valve.
     

    Attached Files:

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  9. CGRBB

    CGRBB Active Member

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    Perhaps anything marked UP or any other way on the outside edge is a sure sign of US manufacture, other than the 552 valve. Seems anything I know for sure is Swiss-made is marked on the front edge of the tang, or the flat face of the cylindrical valve body.
     
  10. Bosley

    Bosley Active Member

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    Wow, I guess these sure are 'parts guns'. On my ERs IIRC there is no designation on the valves. I'll check later on this aft as stated, I'm mobility challenged at present.
     
  11. Bosley

    Bosley Active Member

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    That would make sense as it's consistent with them marking the charging handle "UP".
     
  12. CGRBB

    CGRBB Active Member

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    I’d guess that a silver-colored valve with no markings is actually a Swiss valve used on an early-production Sig USA gun. They got the valves (likely undrilled) from SAN, drilled ports to suit the longer barrel of the US 556, and didn’t find marking necessary.
     
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  13. Bosley

    Bosley Active Member

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    that would make sense. the more I/we find out, the more the clusterfuck at sigusa makes sense as they were mixing and matching parts while they were making parts. So getting a straight answer out of them being impossible is explained by this--they themselves didn't know all of what they were putting out the doors most of the time until they were well into production and by that time, some people were getting quite the bad taste in their mouth dealing with sig usa and their 'incompetence'. Screams 'mismanagement' instead.

    This also makes me wonder how accurate the parts count is on these early guns, the one where the unelected atf created unconstitutional laws about how many imported parts were allowed to be on each gun. The early ones there's really no way to tell most of the time and sig usa doesn't even know, or I bet even kept track.
     
  14. Bosley

    Bosley Active Member

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    reading the other thread, what's with this "made in Israel" stuff? Is that just another version of "FN made their CHF barrels"?
     
  15. CGRBB

    CGRBB Active Member

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    As far as I’m concerned, FN making a barrel doesn’t mean the barrel is any good anyway. I have seen some FN ARs be absolute messes right out of the box.
     
  16. Bosley

    Bosley Active Member

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    An old saying, "there's a reason the horse is in the sale barn" (instead at someone's house/barn).
     
  17. Yuns

    Yuns Member

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    I still can't figure out who made the CHF barrels. I don't think they were made in house at Sig Sauer USA because the 556xi was delayed because of the need to get hammer forging equipment for Sig Sauer USA to make their barrels in house which suggests that they weren't making the barrels prior to the xi. I read one report from someone that the later button rifled barrels were made by Green Mountain Rifle Barrel Co. but again that's unverified.
     
  18. Bosley

    Bosley Active Member

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    Well, I looked at the 2008 catalog from sig usa and they have the swat version of the 556 listed...and it has a hammer forged barrel.
    We can resolve this now if someone has a sig 556 swat, they can check the barrel for a "K" mark. I doubt it has it and if it doesn't, it's a USA made barrel, thus sig NH had a hammer forging operation going on then...and if not, then the source of the rumor of fn doing it for them.
     
  19. Bosley

    Bosley Active Member

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    Here's a thread mentioning the fn made barrels. the faggots that run that board won't allow a non provider email address to join--guess stalked by old boyfriends....
    Sig 556 - SIG Talk
     

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