Originally Posted by wally_allen
it has to do with the number of moving parts in the gun and weight of the the total number of moving parts. semi auto will have more moving parts and the parts move not just once at the time of fireing like in a pump. plus the bolt and hammer don't move independantly from eachother like in a pump. there for a lil over twice the kick. which will effect accuracy. (granted some guns are lighter than others but were talking in a controlled environment here. the receivers being identicle weight just the internals being different)
The moving hammer doesn't kick the gun, the motion is linear. This "kick" is from the expulsion if air.
But, even if accuracy is different (favoring either side), we are talking about less than an inch. Long distance shots will have greater influences such as fps consistency, ball geometry, and air factors.
Point is, no matter who wins the argument, it doesn't really matter.