RPB "sm10" vs RPB "sapm10" 45acp open bolt semis

[Lone Wolf Armament]

Hi all! So I have seen 2 different semi auto open bolt models of the RPB mac10 , the one marked sm10 and another sapm10. The sm10 marked units typically have an 81- or 82- serial # from what I can tell and sapm10 serial as sapXXXXX . Is there any difference between these 2 open bolt semi autos? one more valuable or desired over another? Parts differences? etc

Thanks in advance,
Nick

 

[KickStand]

They should be the same other than the markings. I’ve got a few of each and no difference, parts wise. They’re both desirable due to their rarity. The SAC’s are rarer than the pistols.

 

[Lone Wolf Armament]

ok cool! only thing i could think of is one is earlier production than the other. Thank you for your reply much appreciated!

Nick