That's what I thought also. I can't find it stamped anywhere on the bbl. I contacted Franchi....they said .620 +/- .002. They also said the bore measurement is not stamped on the barrel.

If it goes through the proof house, it is there.

That's what I thought also. The proof Mark is there but there is no number with a decimal that would indicate bore diameter. I'll take a picture of the proof Mark and post it if I can.

The only proof marks on the bbl are on the bottom. The letters CIP with an S under it, the proof house mark then the letters CT in a box. under that is the number 180988. on the opposite side is CM39535Q18. There is no 15.X anywhere on the bbl. Not wanting to argue...but it's not there.

I have access to a Beretta 391. Too k the bbl off and there is all the marks my gun is missing. The proof load info and 15.9 along with the proof house logo and the date code. Should I be concerned that my gun doesn't have this info?

I would love to know the bore dia.....wether it's the .620+/-that the tech quoted me (same as benelli)or the .626+/- that Beretta uses.

Trulock indicates a difference between Benelli and Beretta Mobil chokes in 20 ga.

I hate this thread. It makes me want to get an Affinity in 20 ga. I do not need another shotgun or a 20.

It's has been great so far other than wondering what the bore measures. It shoots a little high....probably 60/40 so nothing crazy like some benellis you hear about. Patterned more steel shot today. Kent Fasteel 2.0. 3" 1oz #3. Mod shot 95% at 30yrds and 80% at 40. IC shot the same load 78% at 30 and 60% at 40. The gun likes the slower 1 oz steel loads better than the 1550fps stuff.

Also shot some 7/8 8oz gun clubs. Nothing exciting. they go bang and land about 5 feet away. Mod gets around 75% patterns at 40yrds.

Really looking forward to dove and September teal seasons.

No. Franchi uses sourced parts, and always has. Beretta 3901's were shipped with Turkish barrels.

Beretta owns plants in Turkey and Spain-- it should be no surprise that they use them.

Just finished up the duck season with the new Affinity 3. Overall it was a slow season because of the warm weather that we had in Oklahoma. Between duck season and shooting clay pigeons a few times over the past couple of months I probably put about 250 to 300 rounds through it. Zero malfunctions and it ate everything I fed it. Shot various #3 and #4 steel loads through a Trulock LM and the oem Mod. The gun handled really well. I made it through the whole season with doing nothing more than wiping it down at the end of the day. When I did break it down to clean it the other day I was amazed at how clean the inertia gun is. I especially like the recoil spring around the magazine tube and how easy it was to clean. It really didn’t even need a cleaning.

I can’t say how much I really enjoy this gun. If anybody is looking for an inertia gun, I wouldn’t hesitate buying another one all over again.

My new 28" Affinity 3 Sporting measures 0.623" in the bore. You have to measure before the choke cut in the barrel.
My IC is .615", M is .610", F is .595", So those give me
0.008", 0.013", 0.028" of constriction with the factory extended chokes.
With these chokes they are about 1/2 of a size on the light side of the markings.