I was having intermittent problems with failure to return to battery on one of the newer releases (2/2/18) every 4-5 mags on reloads only. Talked to CS about it and the said that they thought it was s recoil spring issue and had me send it in. Came back today (after only 3 days) saying the entire extracter group was replaced. I don’t understand that as I bought into the recoil spring theory but can’t tie battery failure to extracter.

Any comments on that from my fellow amateur gunsmith buffs ?

Perhaps extractor tension was too high. The rim of the cartridge slips under the extractor during feeding. If the extractor was interfering with this, I suppose it could cause the slide to stop short of returning to battery.

If the extractor protrudes too far into the casing of the round being chambered it can cause a failure to go into battery

I guess it's possible the extractor was too tight and grabbed the round coming up too hard against the breach slowing down the slide.

Do you have the newer barrel with the relief cuts?

Have not really looked. Where exactly are the relief cuts and I’ll look tomorrow.

Not a good picture, and not mine, but they are cutouts on the front of the barrel hood.
You can barely see it in the upper left hand corner of the hood in this photo. SIG added the cuts to resolve RTB and peening issues.

Sorry about the picture size.

Thank you stoic-one. I just pulled the gun apart and my barrel hood looks exactly as the one in the picture you provided. I never would have picked up on the “cuts” being there as I had nothing to compare it to. So it looks like I do have the newer updates.

I thought it was interesting that they stated that they test fired the weapon with 40 rounds of American Eagle 124 grain and not 115 grain. As I think back I believe I was using 115 on most of the Failure to go back into battery. Had the same problem with 115 in my 938 and a Ruger LC9. Seems like these smaller guns need more of power of heavier loads to cycle properly.