I began crocheting the back of the vest. One thing I noticed about my gauge when working on a larger piece was that it was about an inch or so wider at the bottom than the schematic drawing - with the other measurements following suit. It was fairly close to the next size up, actually. I considered ripping it back and making it match the smaller size. But I didn't. I may regret this, but I'll know better when I finish this portion of the pattern. Life was pretty busy this past week and well, best intentions and all that...
I'm not terribly surprised this happened. Either my substitute stitch pattern or my hook size (or both) could have caused this. My best guess is that it was the hook. The J hook made a fabric that was just too tight for my taste, which is why I went with the K.
The gauge was fine on the narrower front portion of the vest with the same yarn and same hook. Why? Well, I may throw the stitch pattern under the bus for this one. I think the single crochet forces the double crochets to bend over a bit which likely adds a tiny amount of width to a row. This is such a small amount of width, I didn't notice it on the narrower front portion, but by the time the wider back portion was stitched up, all those little bits added up to an inch plus.
Live, crochet, and learn. I'll let you know the verdict of rip back vs. move forward next week.