yes, crome moly is considerably stronger. when i talked to Kreiger about a lightweight barrel, they would sell me a barrel with a profile that was 3 sizes smaller than a SS.
The type of SS and heat treatment would be a factor. The term chrome moly narrows the of steel down to 41xx , where as stainless steel is left wide open.
You can't really say that one "is" stronger than the other! You really are asking a very general question that requires being very specific to give an accurate answer.
1. Specify which alloys you intend to compare.
2. Specify which any type of heat treatment to be used and the resultant hardness.
But! Generaly speaking. the stainless and Chrome Moly steels typically used in barrels and actions are chosen and made to be (by heat treatment) relatively similar in strength and hardness.