I am planning on buying a Wilson 18" .223 Wylde SS barrel but noticed the gas block seat is measured 0.938. I want to install a Syrac adjustable gas block on it but the gas block is rated for a 0.936 seat. I am wondering if there is enough play that this gas block will work, or if I need to figure out a new pairing? Any experience with this type of issue?

Heating the gas block so that it expands will usually handle this small of a difference and should provide a nice tight gas seal on the barrel.

Or perhaps putting the barrel in the freezer for a few hours. Or both methods, freezer and heating the gas block. But a cold barrel will be easier to handle than a hot gas block!

Check some of the other barrel specs and see if the other ones are .938 or if it is just a typo on their page.

I use a Syrac Ordinance clamp on adjustable gas block on my Wilson Combat Ultra Match Wylde barrel with no fitment problems to the barrel at all. It slipped right on and clamped up tight. The .936" gas block has somewhat larger external dimensions than the .750" blocks and wouldn't fit under the old tubular hand guard. After a lot of on-line research, I found that many of the popular hand guards would not fit. I finally ordered a Geissele SM8 to try. I got it to fit, but barely! I had to replace the socket head screws supplied with the Syrac gas block with button head screws to eliminate interference with the new hand guard. It now works great!  Viic

Thank you all for the good advice. Much appreciated!