I'm thinking about this caliber, but have read a lot of manufacturers have struggled with feed problems.  

Who makes the best semi-auto for accuracy and reliability?

Larue.

I haven’t read much about feed issues with 6.5’s, but there have been some reports with 6 creeds running the heavy for caliber bullets.

I’ve seen great reviews of the following:
JP LRP-07
GAP 10
Seekins SP-10
Falkor Defense
F4
Wilson Combat
LaRue

I’ve had good luck with my built LR-6.5 using a ballistic advantage barrel and aero receiver set. Its posted some rediculous groups with handloads. My LaRue UU in 6.5creed has also functioned flawlessly in limited use, with some good groups. I don’t know that it’s the most accurate, but it’s probably the best buy for a large frame currently that you don’t have to piece together. The only issue I have is that the upper and lower fit isn’t tight. My Aero set is tighter and has a tensioning screw if needed. Since the UU doesn’t have a tensioning screw, I had to shim each side of the lower to eliminate the play between the receivers.

I have a 22" LaRue UU, and an 18" Wilson Combat Recon Tactical.

Never had any feed issues with either.  Haven't heard of any feed issues.

For accuracy, my best single groups have been with the Wilson, but overall, they're about even.

Thanks.  Dumb question, but are parts interchangeable for the 6.5 ARs, like for a standard AR-15?

I'd hate to buy something, then need a replacement part 10 years down the road, only to find the original supplier is out of business or sold their business.

Creedmore is going to be on the AR-10 platform. AR-10 has two general patterns DMPS and KAC spec, I think the only things that don’t cross polo are is the upper to lower, everything else works.

Any issues with running the Larue or JP suppressed?

No issues.


As to your question on comparability, here’s a good read. Since there is no standard for large frames, many parts aren’t interchangeable.
Large frame differences

My LaRue has never seen an unsuppressed round.

Who makes the best? You do. Or can. It's not hard to roll yer own.

I run a GAP10 in 6.5 with a TBAC 338 Ultra on it. It's a tack driver and stupid quiet.

LMT also makes a very good setup.