Someone asked me a question which I was unsure of, When did the Invector Plus tubes replace the Invector? This for Browning shotguns.

I may be wrong but I think the "Invector Plus" is designed with a longer forcing cone, and used only with the 3.5 inch magnum guns. The Invector is still used on the standard chambered guns.

Chad

Invector Plus tubes became standard in 1995. They are used on all Brownings now. My wife's little 20 ga sporting clays gun has them.

They are for back-bored (larger internal diameter) barrels, not longer forcing cones. (The forcing cone is at the front of the chamber). Standard Invectors and Invector Plus tubes are *not* interchangeable.

[ 09-06-2002, 15:59: Message edited by: Cold Bore ]

Cold Bore is correct. If you have both type of tubes be sure to mark them clearly. I have both older Brownings and newer and it is well worth the time to sort through the choke tubes and get them with the proper shotguns.

I made the mistake on a goose hunt last year, picked up the wrong choke tubes for the shotgun I brought. I had a choke in the barrel, but I really had to work hard to get the geese to get in close....an added bonus is that my goose calling improved a lot.

My mistake fellas, I have never put any choke tubes in a Browning. For the most part all I get to work on around here are these "pos" Mossbergs. They use an "acrachoke" on their standard guns and "acraplus" chokes on their 3.5 magnums. I should have known not to apply any of mossbergs logic to a good quality shotgun!

Coldbore, shotguns have to have 2 forcing cones, not only the one at the front of the chamber, but one at the muzzle too. Your screw in choke tube is the muzzle forcing cone. A 12 ga nominal bore diameter is .729", an "Improved Cylinder" has a dia of .720", a "Modified choke" has a dia of .710", and a "full choke" has a dia of .700"

Sooner

I have also read that the original Browning Invector tubes are interchangeable with Winchokes and Mosberg Acrachokes, Is this correct?

raamw, IF, I can remember back to my shotgun repair class in school. Yes, Win, Mossberg, and Brownings will interchange, I think almost all choke tubes will interchange, with the exception of Remington. They use a different thread pitch. I am really not a very knowledgeable shotgun 'smith, but I had to work on them in school. I try to keep up with the latest and greatest but around here the only shotguns are cheap, wal mart jobs people buy to shoot at dove and quail. Most of what I get to see is old junk. I have been hearing about the new Browning, I can't remember what it's called, but people are saying it's going to be right up there with the Rem 870.

Sooner

Browning invector, Winchoke, Remchoke have the same threads, but Remchoke has a deeper
shoulder, .010 larger in diam. then the others. The Invector plus and I believe the Accumag are made larger in diam. to prevent using the chokes with a smaller start on the taper in the overbored barrels. The overbore in the Invector plus is around .015. Hastings, Briley, thinwall, and many others have different threads, sizes, etc. The forcing cone is the taper from chamber to bore and the other taper is the choke taper from bore to final choke outlet.
Wow, didn't mean to go this far, but chokes can make a shot gun target shoot like a rifle or open up to almost useless. Lots of fun.
Ed