I am about to begin the first of potentially two new AR builds. With the first build I would like to construct a lightweight carbine with an ops inc brake/collar for suppression. I am trying to determine what the best route would be in order to avoid NFA restrictions on barrel length. Ideally I would like to purchase a 14.5inch barrel and fit it with the ops inc brake and collar. My question though is if this would satisfy NFA requirements  of 16 inches (and is the brake permanently pinned)? Alternatively, I would get a 16 inch and could cut it down if the 14.5 was not long enough with the brake.

Anybody have any experience with this? I would like to have the capability to suppress a carbine and also move it to an SPR or my existing middy if I decide to retrofit it with brake/collar.

Am I dumb for wanting this in a lightweight AR? Should I just A-post it or stick to standard flash hider/break.

Thanks

It could be done but I would choose something other than the OPS brake.
The threads on the brake go all the way to the back and it would be very hard to drill and pin it and keep the suppressor threads intact.

I would use a AAC 51T or get a suppressor that would use the ring grove on a Vortex or A2, A2X.
Or if you are set on the OPS do the paper for a SBR and dont try and pin it.

See in this pic where the treads are and think how it would be pinned.

The SEI Vortex Zops mount has wrench flats that you can pin through.

I had not seen this before till I looked it up.
Yes you could drill into the flats and pin it that way.

Part #     1001V-G6A2-SBV