LMT MRP CQB 300BLK Expectations

AR/M4 Beyond 5.56/.223
1

I’ve done my best at searching the forums, but haven’t been able to piece together a sufficient answer. I recently converted one of my LMT MRP CQB carbines to 300BLK with a 10.5" barrel. I also have a 762-SDN6 that should be out of ATF jail within the coming months. My question is, what can I expect, with regards to proper functioning, when running supers and subs with and without the can if the only thing I’ve so far is install an H2 buffer? Should I start with a heavier buffer, different spring, anticipate the need for an adjustable gas block, etc? This will be my first experience with 300BLK, and any advice will be greatly appreciated.

Thanks,
Pete

2

40arpnet,
While I do not have the 10.5 inch barrel yet, I do have experience with the 16 inch 300 blk barrel. I changed nothing but the barrel and bcg (I have the piston driven 5.56). The 300 blk runs perfectly with anything I feed it…suppressed/unsuppressed, subs and supers loaded alternately in the same magazine. The pistol length gas system “should” not require changes. When I get my 10.5 in barrel I plan on installing and firing it with no modifications.