i bought a Carbon 15 9mm pistol about two weeks ago. initially, i had sporadic problems with FTL when using 115 FMJ and 147 JHP. so, i called Bushmaster customer service on March 2 to see what they could do. they asked me to send it back so they could take a look at it. within 15 min, i had a UPS shipping label (prepaid by Bushmaster) and dropped it off at the local UPS Store. i figured it would take Bushmaster at least 3-4 weeks to get to it. to my surprise, i received my repaired pistol on March 9. so, thats 6.5 days including shipping time for the repair - all at Bushmaster's expense.
in addition to polishing the ramp and giving the gun a good inspection, they added an ambidextrous safety lever (that i had asked about) free of charge.
fyi - the tech who examined and repaired the gun noted that the factory mag (ProMag) doesn't like 147 JHP. based my experiences, it seems that 124gr FMJ is the ideal round when using ProMags. 115gr FMJ is hit or miss. guess i'll look into some different mags and see what works better.
this is my second Bushmaster firearm (also have a Carbon 15 M4), and i love both of them. the pistol is a VERY fun gun to shoot.