Invector Chokes in an Invector Plus Barrel?

[CrawfishStu]

I have an FN SLP.
This one.
http://www.fnhusa.com/l/products/commercial/shotguns/slp-series/slp-tactical/

It says this about the barrel.

BARREL

Hard-chromed bore and 3" chamber
Standard Invector™ interchangeable choke tubes
Accessory sporting barrels are available

Confirmed here.

I bought a barrel. I was going back and forth with a guy about a 22" barrel with Invector chokes.
I found another one after he decided to keep it. I went and picked it up. It is unused. He says he got it from Midway.
This is the only one listed on FN's site.
http://www.fnhusa.com/l/products/commercial/accessories/shotguns/slp-autoloading-shotgun-barrels/
Product No: 3088929500
22″ FN SLP MK I non-back-bored barrel with 3″ chamber, Weaver-pattern cantilever scope mount, adjustable rifle sights, one Standard Invector™ Improved choke tube.
However....on MidwayUSA
http://www.midwayusa.com/product/97...embly-fn-slp-mk1-12-gauge-3-22-improved-black
It says this about the barrel.
Note: Barrels use the Invector Plus choke system and ship with one choke tube included (Supplied choke listed in description)
This is the barrel.

Which sucks....because I have invector tubes......but wait.
The tube in the barrel is the one on the far right. The one from my original barrel and others that I have been using are to the left.

What the hell? I googled if I can use an invector tube in an invector plus barrel and got the standard yes, no, you will shoot your eyes out answers from the intertards.

Invector OK in an invector plus barrel?

 

[CrawfishStu]

Found this.

From a Browning manual...

The Invector-Plus system is a screw in choke tube system with interchangeable tubes. You can confirm this by reading the inscription on the barrel. The words INVECTOR-PLUS mean your shotgun uses the Invector-Plus choke tube system designed for use in Browning 12 gauge shotguns with back-bored barrels...
CAUTION: Invector-Plus tubes are for use in Browning back-bored barrels only (.754" +0 -.005), and are not interchangeable with standard 12 gauge Invector choke tubes. Do not use Invector Plus tubes in barrels threaded for the Standard Invector tubes. Do not use Standard Invector tubes in barrels threaded for Invector Plus tubes. Failure to follow these warnings may cause damage to your gun and cause injury to yourself and others.

But how can this be true? This thing is new in the box with shipping label from midway with cosmo all over it and the tube. It was even in a brown paper/cosmo wrapper and a sealed bag in the box. I mean.....it doesn't look like he ever took it out of the box.

 

[Cochise]

they are different sizes internally, dont know about the threads. Do not interchange them.
I have guns that use 1 or the other of the 2 and they are both fine but not interchangable. The plus is a larger bore size even thought they are both nominally 12 gauge the Plus is moving towards being 11 gauge on the theory of less recoil.

 

[CrawfishStu]

Do the chokes "fit" in both barrels? I put the one from my 18" barrel in the 22" barrel and the fit/feel was identical and everything lined up inside when I scoped it. I will mike the barrels real fast and give you a measurement to make sure the threads aren't just making soft contact.

 

[CrawfishStu]

Also, thanks for the quick response. I wanted to shoot this tomorrow.

 

[CrawfishStu]

Both measure out to .81" with no choke in there.
Could the stamp be wrong?

 

[CrawfishStu]

I left a message at FN but.....I decided to shoot it Sunday at the match. Everything that I read showed that the invector would not even seat in the invector plus barrel. That it would be obvious that it didn't fit at all.

Invector

Invector Plus

So after seeing all of that and putting the chokes in the barrel, I decided that the barrel stamp is just wrong. There is just no way it is invector plus. 100 rounds down the barrel and it's perfect. I'm very happy with the extra bit of length.

 

[PapiBarcelona]

Sounds right, you definitely don't have invector plus.

That's odd, the SLP, the SX3 and the Maxus are basically the same shotgun. SX3 and Maxus use invector plus.