I'll tell you how mine does after I get it assembled. I can't see that it would only do 1.5" groups at 100 yards. My Regular SAR-1 does like 3" groups ( 4 shots) at 100 yards with Wolf 7.5 cents per round ammo and an 8x POSP scope.
OTOH, I am a pretty decent shooter, I have hit a quarter with a .338 Win. mag. at 100 yards with a 4x scope and just recently (2 weekends ago) put 2 - .243 bullets through the same hole (on successive shots, not like 15 shots and 2 happened to go through the same hole) at 100 yards with a 3-12x scope on my dads new hunting Rifle. I do think that one thing that will influence the rifles accuracy is the type of ammo that you repeatedly use. You can't use cheap ammo or I am sure that it will mar the finish of the barrel and subsequently make it less accurate. We'll see though. I hope to have mine together sometime soon, as soon as I get my parts. :)