Would accuracy potential be significantly greater as a straight pull rifle vs semi-auto?  I was considering this option for a scopes straight pull competition rifle.  

I have plenty of AR10 semi autos but live the traditional feel of an M1A styled rifle.  This would be for target shooting and possibly competition.  I also have a rem 700 in 6.5 creed.  

Any thoughts?

I was thinking about a purpose built rifle. Would it benefit from not having a gas block,  and piston?

But then it wouldn't be an M1A, it would be a single shot based on the M1A so . . . . . .

I kinda feel like the stock comb is too low for it to benefit much from any accuracy gained from a straight pull bolt. The gun rocks back and up a considerable amount.

Unless you’re going to build a whole new rifle, you’re gonna get better inherent accuracy gains by making the cycle more consistent. Chrome Silicon springs, polish faces of your trigger, bed your stock, heavier barrel are going to do much more for your accuracy and maintain the intended purpose of the rifle than making it a bolt gun.

If you want an accurate straight pull rifle get a Swiss K-31.

The gas system doesn't go until the bullet clears the barrel.  You still have a big floppy oprod hanging off the barrel.  And the oprod handle offers you only a tiny fraction of the leverage that a bolt gun has for primary extraction.