I should be getting my approved RLL paperwork in the next week or two.  The RLL I’m getting is coming with ONE paddle and the KNS Protector.

Where can I buy quality paddle spares, ideally with suitable clearance for the KNS Protector?

What thicknesses should I buy or keep onhand?

If a vendor isn’t readily available, what is the material, thickness and temper/hardness needed to make my own paddles and what are the dimensions? Again, dimensions suitable for KNS Protector usage.

What thickness do you need?  Shoot me a PM with your address and I'll send you some.
v/r,
Esox

I guess I don’t really know what thickness (yet). I was under the impression that one ensures the paddle is straight/unbent and then goes about figuring what paddle thickness is ideal for their carrier/upper/lower setup by testing the timing.

Let bolt go slowly into battery; no sear trip
Let bolt go with more gusto; sear should trip.

I do know the paddle that is coming with my RLL looked well used and had an ever-so-slight bow to it. I figure I’d flatten it out and work from there.

The thickness of the paddle depends on how the carrier is cut. If it is a 'standard' SP1 carrier, then the rear of the carrier is usually ~0.400" and a 0.032" paddle works well. If it is a milled down M16 carrier, that dimension depends on how much they took off. Many people mill it to 0.390" to use thicker 0.040" paddles that resist bending better. Paddles last a shockingly long time (even bent) and are cheap/free.

Setting up RLL hosts is really easy and worth taking the time to learn. Ask away here and there are some great guys who can help you out.

v/r,
Esox

My carrier is unmilled at this time. I was going to mill my Colt BCG myself and cold blue the cut surface. I’d heard .380 mentioned numerous places, but it sounds like maybe I should start with .390” and take off more if needed. It’s easier to take material off rather than add it back on. Plus that way I can plan to use a .040 paddle (25% thicker than the .032 paddle).

It's certainly easier to take more off than put it back on. Since you are milling your own carriers, you can pick whatever thickness you want. If you err on the side of leaving more material, it leaves you room to tailor all of your barreled uppers to work well with one paddle. I personally cut mine ~0.390" and that seems to work with both 32 and 40 thousandths thick paddles. The way you really should mill the carriers is to have a dedicated carrier for each barreled upper and use a feeler gauge to get a consistent gap between that upper's rear lug and that carrier with it completely in battery. This would help to avoid any tolerance stacking issues between various builds/parts.

Also, don't forget to mill about 40 thou off the bottom of the rear lug of your upper to account for the thickness of the RLL protector. I also like to clearance my hammer for added insurance against hitting the RLL.

What sort of thickness are you left with on your upper receiver between the rear pin hole and the bottom of the rear lug after milling ~.040” off of it? There’s not much material there to begin with...