I have a number of Invector+ I'll measure for you.
The 'standard' bore has been said to be .741 or .737 depending on who you read. They vary. It's just the way it is. Browning has been taken to task on this. They state a tolerance of -.003 from .741. They vary more than that.
1. BT-99 circa 2006. .736"
2. Cynergy 2004. .737" both.
3. CXS 2019. .735" both.
Factory supplied flush chokes referencing the 'for lead' marking.
1. Mod: Tapers back to bore in about 1.25". Tapers to .726 with about 1/2" of parallel.
2. IC: Similar, .733"
3: Skeet: Similar, .733", so identical to the IC.
The IC is a black finish and came with one of the guns. The skeet chokes (I bought a pair before I knew better) are silver finish and may or may not be stainless. They are Browning branded.
Briley flush mount CYL: Gently taper to .738", about 3/8" of parallel.
Briley extended MOD: .719". This a GREAT trap choke in the BT-99 back to 22 yards.
Briley extended IM: .713". Quite effective at 27 yard trap, and even breaks the ones I point correctly from the picnic table which is about 35 yards behind the trap. I see no performance difference between this rig and a Beretta trap gun with their typical .722 bore and .037 of hard choke. I've never seen the need to buy a Briley full choke for INV+.
Briley extended IC: .728"
Carlson extended CYL: .739". These have a slightly longer parallel than the Brileys.
Carlson extended LM: .725"
Carlsons extended SKT: .733"
Browning Midas Full: .704
Browning Midas MOD: .719
Browning Midas IC: .731
The Browning flush 'Full' that came with the trap gun was either given away or disposed of in disgust. It was a lousy choke.
That's the report.
Good luck.
