|
S |
M |
T |
W |
T |
F |
S |
|
|
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
9
|
10
|
11
|
12
|
13
|
14
|
15
|
16
|
17
|
18
|
19
|
20
|
21
|
22
|
23
|
24
|
25
|
26
|
27
|
28
|
29
|
30
|
31
|
|
|
2 members (Marks_21, SKB),
486
guests, and
6
robots. |
Key:
Admin,
Global Mod,
Mod
|
|
Forums10
Topics38,549
Posts546,219
Members14,423
|
Most Online1,344 Apr 29th, 2024
|
|
|
Joined: Feb 2003
Posts: 4,041 Likes: 50
Sidelock
|
Sidelock
Joined: Feb 2003
Posts: 4,041 Likes: 50 |
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.
"The price of good shotgunnery is constant practice" - Fred Kimble
|
|
|
|
Joined: Jul 2019
Posts: 22
Boxlock
|
OP
Boxlock
Joined: Jul 2019
Posts: 22 |
Thankyou Shotgunjones for taking the time and trouble to supply this extensive information. Found in Brownings blurb about 0.742" being "the ideal interior barrel diameter for back-bored 12 gauge", equating to 18.85mm. so these tubes would probably be proof stamped at 18.8
Are all of your chokes generally 0.750" bore at the threaded (breech) end as mine? or does a particular manufacturer tend to have a smaller bore at the breech end of its chokes? which would then reduce the step in my 18.7 mm gun It seems the factory Browning flush chokes need tossing in the bin! Thanks again
|
|
|
|
Joined: Feb 2003
Posts: 4,041 Likes: 50
Sidelock
|
Sidelock
Joined: Feb 2003
Posts: 4,041 Likes: 50 |
They all seem similar as far as initial diameter.
If you can't get Briley or Carlson's there, my brother uses the Browning Midas in 'cylinder' for skeet to good effect.
As mentioned, those are apparently made by Briley but not identical internally to their own brand. They just do what Browning specs.
They're also black with a snazzy gold ring and of course they cost a fortune. My CXS came with 3 of them instead of the flush ones, thankfully. They shoot OK.
"The price of good shotgunnery is constant practice" - Fred Kimble
|
|
|
|
Joined: Jul 2019
Posts: 22
Boxlock
|
OP
Boxlock
Joined: Jul 2019
Posts: 22 |
Just a brief update on my quest for aftermarket chokes for my B525. Briley's are available in the UK but couldn't find them in stock in the sizes and types that i was after. Decided to try Teague precision who are based in UK. Liked the look of their extended but unported type in stainless and ordered a cylinder, skeet and 3/8 (light mod)for my 18.7mm (0.736") bores. They arrived today, finished very nicely inside and out and with a good knurled extended section big enough to screw in by hand so no need for their special tapered tool. Some measurements taken:
size/entry/exit/nom restriction/Actual restriction(bore - exit) Cyl/0.752"/0.735"/0.000"/0.001" Skt/0.752"/0.729"/0.005"/0.007" 3/8/0.752"/0.721"/0.015"/0.015"
So it would seem for Teague, and perhaps other makers?, the actual restriction difference between barrel bore and choke exit pretty well matches the nominal restriction for that size choke. For more open chokes anyway. The "step" still remains, so therefore still the potential for jugging effect, so it will be interesting to see if they perform true to size or tighter. I have dropped from 1/4 and 1/2 to skt and 3/8 anticipating them to be tighter.
|
|
|
|
Joined: Feb 2003
Posts: 4,041 Likes: 50
Sidelock
|
Sidelock
Joined: Feb 2003
Posts: 4,041 Likes: 50 |
Glad you found what you were looking for.
I take it Teague does not use notches for torque.
A "soft jaw" pliers works pretty well for that and beats the conical wrench.
"The price of good shotgunnery is constant practice" - Fred Kimble
|
|
|
|
Joined: Jul 2019
Posts: 22
Boxlock
|
OP
Boxlock
Joined: Jul 2019
Posts: 22 |
Yep, we will see how good they are in due course! No notches in these extended chokes, rely on friction fit with the "special" key only, but you can get them sufficiently tight by hand on the knurling, and if too tight to remove, the pliers would do the job i'm sure!
|
|
|
|
|
|