So, I've tried searching, but I haven't found the answers to these specific questions. Any and all help greatly appreciated!

1. Cut down LMT factory MRP barrel from 14.5" to 10.5"
If I do this, will I need to adjust the gas port size, and/or switch to an adjustable gas block, or will it run as-is? Any other concerns of which I should be aware? Assume mostly quality 55gr ammo for plinking, hand loaded heavier stuff down the road. 95% unsuppressed, running with an A5 receiver/buffer system and stock BCM bolt carrier group.


2. Cut down LMT factory MRP 300blk barrel from 16" to 10.5"
Again, if I do this, will I need to adjust the gas port size, and/or switch to an adjustable gas block, or will it run as-is? Any other concerns of which I should be aware? Assume mostly quality supersonic (125-150gr) ammo for plinking, hand loaded 125-150 supersonics down the road. 100% unsuppressed, running with an A5 receiver/buffer system and stock BCM bolt carrier group.


3. Cut down LMT MRP rifle length upper to CQB length
I have two of these rifle length uppers sitting around (with 16" barrels), and would use them on SBRs (with different barrels) if they were the shorter CQB rail length. Is this even possible? If so, can anyone do it, or should I go to an acknowledged specialist. Is it a stupid idea? I could just sell them as used uppers and buy more CQBs, but maybe this would be an easier way to go? Or not?

Thanks in advance for your advice!