my sig 12.5 pistol build........sagebrush

[sagebrush]

I have been in "my room" all morning cleaning, loading, sorting and started working on sig build. first thing I did was knock out the pin where the bolt locks up that went fine thanks 98. my toolcraft bcg was laying there so I thought I would take it apart and check headspace, came apart fine. I have a set of Clymer .308 win. go-no go gauges that I used successfully on my .243 and .260 build and they work well. I put the no-go in the sig chamber and the bolt would not go into the chamber lugs, great. I put the go gauge in the chamber and the bolt will still not engage lugs. i'm thinking maybe try another bolt and then think, I have a box of 150gr. factory loads. I put one in chamber and the bolt will engage lugs, snug fit. so i'm thinking maybe with enough lube this might get by? i'm looking for some other opinions on this....thoughts..

[98Z5V]

No-Go works like it's supposed to, so you don't have excessive headspace, and that's usually the "danger zone" to look at.  Chamber might be tight - then again, it might appear "tight" in every aspect, until you shoot it.  From the gauge readings, chamber looks tight.  From the live-round test - it engaged.  I'd shoot it, if it was mine, in this circumstance. 

What did you come up with for a gas tube length?

[sagebrush]

1 hour ago, 98Z5V said:

No-Go works like it's supposed to, so you don't have excessive headspace, and that's usually the "danger zone" to look at.  Chamber might be tight - then again, it might appear "tight" in every aspect, until you shoot it.  From the gauge readings, chamber looks tight.  From the live-round test - it engaged.  I'd shoot it, if it was mine, in this circumstance. 

What did you come up with for a gas tube length?

I haven't made up mind on whether to move gas block back like heminut did. still contemplating that. haven't measured. thanks for your opinion on chamber, wanted a check on my thinking...

[98Z5V]

I used a KAK Lo-Pro gas block, that's 15/16" front to back, long.  Both set screws are on the 0.750" portion of the barrel.  Went with the White Oak Armament custom gas tube.  Even if you move the gas port back, you'll still need a custom gas tube. 

[sagebrush]

24 minutes ago, sagebrush said:

I haven't made up mind on whether to move gas block back like heminut did. still contemplating that. haven't measured. thanks for your opinion on chamber, wanted a check on my thinking...

went and measured was 10.4 ctr to ctr. will figure it will be 11" overall. same as yours. 

[sagebrush]

2 hours ago, 98Z5V said:

No-Go works like it's supposed to, so you don't have excessive headspace, and that's usually the "danger zone" to look at.  Chamber might be tight - then again, it might appear "tight" in every aspect, until you shoot it.  From the gauge readings, chamber looks tight.  From the live-round test - it engaged.  I'd shoot it, if it was mine, in this circumstance. 

What did you come up with for a gas tube length?

went and measured was 10.4 ctr to ctr. will figure it will be 11" overall. same as yours.

[98Z5V]

6 minutes ago, sagebrush said:

went and measured was 10.4 ctr to ctr. will figure it will be 11" overall. same as yours.

Yep.  You'll need the 11.000" tube, AR-10 bend.

[shooterrex]

Both of mine are 11 1/16"  Both come to the middle of the cut out.

[sagebrush]

3 hours ago, shooterrex said:

Both of mine are 11 1/16"  Both come to the middle of the cut out.

hope my measurement is as good as yours

[Radioactive]

17 hours ago, sagebrush said:

hope my measurement is as good as yours

🙀uhmmm might be too much info right there

[sagebrush]

2 hours ago, Radioactive said:

🙀uhmmm might be too much info right there

boys will be boys

[sagebrush]

ordered the custom gas tube from woa, said about three weeks. ordered springco recoil spring and heavy buffer. kak gas block is in order also

[98Z5V]