Gas Block Material, consideration?

[Californio]

So I decided I want a 26" SS Bull barrel for squirrels that would require a .936 lo-pro gas block. Given the gas seal is important, does it matter if the block is aluminum, steel or stainless steel. I wonder about dissimilar metals expanding at different rates. I would assume for best precision a SS block would be best but all is see is aluminum and 4140 steel.

Does the gas block material matter?

[ar15barrels]

If the block is well attached, aluminum works fine.
Steel and aluminum do have drastically different expansion rates, but the AR has enough extra gas in the gas system that a smal amount of leakage should not be an issue.

As for stainless steel vs mild or chromoly steel, the expansion ratios are so close together that it would not matter if you used regular steels or stainless steel as they will both expand the same as the barrel.

[Californio]

Thanks Randall,

Hope your back is coming along without a lot of pain.