Hey HK pro, turns out the vector v53 that has a 16inch barrel and faux suppressor has a lp #15. Ive maybe shot 150 rounds of 556 xm193 and developed a very light roller mark on the inside of the rail towards the rear. Im pretty anal retentive about roller marks and want to nip this in the bud. Ill be changing out the recoil spring and assembly, checking bolt gap as well. Assuming gap is within spec could just a spring and a lp #7 fix this? I like the gun but am worried ill be shooting it quite a bit until i get around to a stamp for it, without addressing the marks in my experience on an mke i owned, they just keep getting bigger assuming normal pressure ammo. Feedback is highly appreciated, thanks.