20ga Backbored barrels

[Mr16Gauge]

Can someone "shed some light" on which 20ga use the backbored barrel system?

Partner and i seem to disagree.

Thank you

[TrkyHntr]

I think the invector plus barrel systems are bigger than the standard bore.

[Mr16Gauge]

Indeed they are.

We are wondering which 20gas use that system.

We know thatcertain Browning use the Invector plus sustem, but are wondering if others might also?

Appreciate the input

[TrkyHntr]

The winchester SX2 or SX3 are the only other guns I know of that use that choke system.

[Mr16Gauge]

Thanks for the update

[gobblergls]

The new Ithaca M37 20 gauge is Invector +.

[Mr16Gauge]

You are indeed correct in that is what I was/am seeking.

Appreciate all the input.

The .630 overbore will make the barrel the same "rough" diameter as the 16 gauge.

Thank you again

Now, can we get someone to "overbore" a Remington barrel?

[Mr16Gauge]

Actually a 16 is .663 but what I was trying to say is that at .630 the bore will be approaching a 16ga.

Thanks again

[MOSPURS]

The new Ithaca M37 20 gauge is Invector +.

actually i don't think these are backbored
they just happen to use inv+ choke pattern

i know thats true on their 12's

[Mild Bill]

Backboring is actually boring an existing barrel to a larger diameter, and is an after market application.

What you are asking about is which 20 ga guns are Over bored which is any factory barrel diameter that is larger than a guage's nominal bore diameter.

The answer is All of your major manufactures 20 ga guns are Over bore. The nominal bore diameter for a 20 ga shotgun is .615" and your major manufactures 20 ga bore diameters are as follows:

Remington, Charles Daly (RemChoke) - .620"
Beretta, Benelli (Mobil Choke) - .625"
Winchester (Invector) - .620"
Browning, Winchester (Invector Plus) - .630"

They may supposed to be that diameter but I have two Rem 870 barrels and one winchester 1200 barrel that all measure 0.615 according to my skeets bore gauge.....