this is correct.anhedonic said:Josh is right-the 556 is not indexed. I believe the gas block roll pin hole locations are drilled after barrel install to time the block to the receiver, so yes they are each a unique assembly.
timing the threads on all the barrels, as well as all the receivers, adds an unnecessary level of complexity to both the manufacturing and assembly process.ullie said:...the barrel change out proceedure on the 556 should be the same as that on the 55x series...i've never changed out a barrel on a 556...but have on the 55x...but to not have the barrels index on the 556s...so to speak...would be an inexcusable blunder on the part of Sig Sauer...they should have the manufacturing expertise and technology to hold the appropiate tollerances...
...i'm curious why some of you feel that they won't...what do you base this on...if it's true...changing out a barrel on a 556 would be next to impossible...problematic for sure...and would be a deal breaker for almost all professional endusers...a market Sig Sauer badly wants...
...i'm having a hard time swollowing this...
...just saying...
...the Swiss have been doing this for decades...as have others..."unnecessary" ???...quite the opposite !...in order to have interchangability of components...especially components that need to be replaced due to wear...such as the barrel in a modern assualt rifle...the proceedure needs to be strightfoward and simple...which it is in the 55x series...the 556 should be no different...the ability to hold the tollerances required in the print specifications during the production phase is well within the ability of a modern facility such as that which Sig Sauer has available...bullyforyou said:timing the threads on all the barrels, as well as all the receivers, adds an unnecessary level of complexity to both the manufacturing and assembly process.
...and still is...what is the basis of your statement...something that was posted on the internet...a small sample of issues some people have had changing out barrels...some vendor's claims....perhaps due to the fact that they can't produce barrels that will index...or do you have a credible contact in the Sig Sauer organization that can confirm this based on the print specifications Sig Sauer is using and their manufacturing protocols...ullie said:...i'm curious why some of you feel that they won't...what do you base this on...
ullie said:...the Swiss have been doing this for decades...as have others..."unnecessary" ???...quite the opposite !...in order to have interchangability of components...especially components that need to be replaced due to wear...such as the barrel in a modern assualt rifle...the proceedure needs to be strightfoward and simple...which it is in the 55x series...the 556 should be no different...the ability to hold the tollerances required in the print specifications during the production phase is well within the ability of a modern facility such as that which Sig Sauer has available...bullyforyou said:timing the threads on all the barrels, as well as all the receivers, adds an unnecessary level of complexity to both the manufacturing and assembly process.
1) the 55X design is over 30 years old now; not something i would call a "modern rifle". many similar arms of that era do NOT have quick-change barrels. the swiss never intended for the barrel swaps to be done by the individual end-user.
2) if the end-user is taken out of the equation, barrel swaps ARE simple. in fact, they are simpler if the barrels aren't indexed.
3) timing threads is more difficult than people typically believe it to be. in the end, depending on thread class and pitch, even working to *tenths* (0.0001") you still can yield mating parts that only time up at ±10, 15, even 20 degrees. indexing ranges like that may not necessarily allow for propper torque. and working to tenths is doable but still a PITA even in modern machine shops.
4) lastly, what the swiss DID, has little bearing on what sig DOES.
..anyway...my question was...
...and still is...what is the basis of your statement...something that was posted on the internet...a small sample of issues some people have had changing out barrels...some vendor's claims....perhaps due to the fact that they can't produce barrels that will index...or do you have a credible contact in the Sig Sauer organization that can confirm this based on the print specifications Sig Sauer is using and their manufacturing protocals...ullie said:...i'm curious why some of you feel that they won't...what do you base this on...
...like i've mentioned...i've never changed out a barrel on a 556...and i'm curious if this is true or just another internet rumor being parroted over and over again based on one or two individuals having issues with "their" attempt to change out a barrel on a 556 with another "factory" produced barrel...or possibly an aftermarket barrel...
..just asking...
bullyforyou said:1) the 55X design is over 30 years old now; not something i would call a "modern rifle". many similar arms of that era do NOT have quick-change barrels. the swiss never intended for the barrel swaps to be done by the individual end-user.
2) if the end-user is taken out of the equation, barrel swaps ARE simple. in fact, they are simpler if the barrels aren't indexed.
3) timing threads is more difficult than people typically believe it to be. in the end, depending on thread class and pitch, even working to *tenths* (0.0001") you still can yield mating parts that only time up at ±10, 15, even 20 degrees. indexing ranges like that may not necessarily allow for propper torque. and working to tenths is doable but still a PITA even in modern machine shops.
4) lastly, what the swiss DID, has little bearing on what sig DOES.
...so you can't give me a "definative" answer...just your opinion...based on your experience and hearsay...got it...bullyforyou said:regarding the rest of your question/comment - i work with several of sig's vendors, i've seen plenty of sigs parts in process, i've seen their prints on certain parts (though i've not studied them), and i have several friends who work for sig, all of whom would be considered "credible contacts".
bullyforyou said:i'm not going to speak for sig. if you really want to know, call them. from my end, i haven't seen anything that would give me reason to believe that the threads are, or even should be, timed. my statement is only my opinion, and in the opinion of a guy in a similar line of work, untimed threads would be quicker to produce, quicker and easier to assemble. hell, there is even a substantial product liability standpoint to be argued when considering end-user serviceability[
bullyforyou said:this is correct.anhedonic said:Josh is right-the 556 is not indexed. I believe the gas block roll pin hole locations are drilled after barrel install to time the block to the receiver, so yes they are each a unique assembly.
if you wanted to swap pre-drilled barrels, you'd either need several at your disposal so you can try them until you find one that's close
...so now it's only your opinion...not a statement of fact as before...got it...bullyforyou said:my statement is only my opinion
bullyforyou said:2) if the end-user is taken out of the equation, barrel swaps ARE simple. in fact, they are simpler if the barrels aren't indexed.
... :?bullyforyou said:if you wanted to swap pre-drilled barrels, you'd either need several at your disposal so you can try them until you find one that's close, or...
i suppose you could face off a bit of the trunion, and then cut some spacer washers at a variety of thicknesses so you could time any barrel correctly (like FAL and some galil builds).
...not saying they are or aren't timed...just saying i find it hard to believe...but considering some of the avenues Sig Sauer has taken...it would be just another inexcusable blunder on Sig Sauer's part...IMO...ullie said:...the barrel change out proceedure on the 556 should be the same as that on the 55x series...i've never changed out a barrel on a 556...but have on the 55x...but to not have the barrels index on the 556s...so to speak...would be an inexcusable blunder on the part of Sig Sauer...they should have the manufacturing expertise and technology to hold the appropiate tollerances...
...i'm curious why some of you feel that they won't...what do you base this on...if it's true...changing out a barrel on a 556 would be next to impossible...problematic for sure...and would be a deal breaker for almost all professional endusers...a market Sig Sauer badly wants...
...i'm having a hard time swollowing this...
...just saying...
...actually...the LEO/agency price for a Swiss 55x was just around $1100 here in the United States....and that included a Swiss magazine... :wink:anhedonic said:Sounds like some of you wanted a SAN version at a Sauer price...manufacturing shortcuts are understandable and necessary to meet the price point required (unless bankruptcy is your goal). SIG retailed these far below what the original 55X rifles would have cost-and you can't just wish that MSRP into existence, you have to reengineer it to that target.
