First post here so take it easy on me. I bought my first can last week in a AAC 5.56 sd and am now playing the waiting game. But I was just curious how much clearance I should have between the rail and suppressor? I plan on getting a BCM 11.5 upper and want the rail to run as close to the can as possible without contacting. Would a 11" rail cut it too close? Any input or rail suggestions are appreciated. Thanks.

get a rail that has a larger ID than the silencer's OD. then get a rail that's any length you want, it can even be longer than your barrel

heres an example of a 10.5" barrel and a 12" rail.

I was trying to avoid the can going under the rail. I would like easy access to the qd mount so I can switch it between rifles.

Rothperson87 wrote:I was trying to avoid the can going under the rail. I would like easy access to the qd mount so I can switch it between rifles.

Then you'll have to measure from the front of your upper to just behind the muzzle device.
Take into account whether the rear of your can extends passed this point.
Get a rail equal to or smaller than this dimension.

I would do that but I don't yet have the upper or suppressor. I was hoping someone would have a similar setup and tell me what their specs were.