I noticed today while shooting skeet that my Briley choke didn't look right when looking through the barrel (from the chamber side). I found that it had a lot of lead buildup. I had to clean the damn thing with a brass brush in a drill and it still took a minute or two. Yes, I should clean them more often, but the interesting thing was that the Beretta choke had very little buildup. They're both skeet chokes and I always load 2 so they should have roughly the same amount of shells through them. Has this happened to anyone else, and what would be causing it?

Briley choke

Beretta choke

Post cleaning

I used to be a very big Briley fan...not so much anymore, they have some real problems with quality. Had to get a new Parcours barrel after they threaded it for thinwall choke's. Could not remove the chokes...their answer was to heat the barrel with a torch... luckily Krieghoff stepped up and replaced the barrel. Have other issues with their trigger work and sub gauge tubes. I believe they have gotten so big, and after the owner died quality has suffered. I hope they start getting it right. long story short it looks like their choke may be more restrictive??
Are you sure that is lead and not wadding cup residue?

No, I pretty much only shoot skeet chokes when shooting skeet, so these two chokes should have the same amount of shells, of the same variety of ammo.

When cleaning it out, it definitely felt like lead to me.

Mostly plastic fowling and as you learned it can require a drill hooked to a brush to get out. I run mine through a sonic cleaner with solution of simple green and distilled water the use the drill/brush to clean them. That being said I don't worry about it too often, maybe 4-5k rounds? Only thing I notice is that the choke started to pattern a fraction of a bit tighter which is never a bad thing IMO.

I guess I'm wrong about it being lead buildup, and yeah I've probably shot 15 or so flats since I last cleaned the chokes.