Beretta M9 and civilian M92 bore groove diameters

I have an M92 FS made in Italy in 2016 that slugs at .358 groove diameter. Beretta tells me via email that their maximum groove spec. is 9.1mm. Since it's within spec. I don't believe they would replace it, particularly since apparently many 9mms have groove diameters about like mine; several have been reported on this site. I am considering trying to locate a Beretta mfg. 92FS barrel with a groove diameter closer to .355-.356. My pistol is the compact model with the 4.3" bbl, but if I could locate a 4.9" bbl with suitable groove diameter I would get it and cut it down to 4.3" and recrown. This brings up a couple of questions:

Have any of you managed to find a Beretta mfg. barrel in the .355-.356 range? At this point I'm not interested in aftermarket barrels

Have you cut down a 4.9" bbl to 4.3" and how did it function in your gun? Seems like there shouldn't be any problem with cutting one down.

Can the longer barrel be installed on my compact frame and slide and the gun function without damaging anything? If I find a suitable barrel I might want to test fire it before cutting it.

Is there any outside dimensional difference in a military M9 barrel and a civilian M92 barrel? Thanks

My experience is with one Beretta 92 and several M9 barrels(probably USA manufacture).
All the Beretta barrels, 5 in all, measured the same as yours. Why I ended up with so many is, I have several Taurus PT92 pistols which(mostly) are an exact copy of the Beretta 92 with the exception of the magazines and latch. The barrels and locking lug are drop in replacements for the Taurus barrels.
The Taurus barrels have the rifling cut very shallow. Because of this, they don't work well with cast boolits. Lots of rifling skid and poor accuracy. They work fine with jacketed.
They measure .355.
I purchased several M9 barrels off eBay as replacements since the rifling is cut much deeper and they handle cast very well.
The chambers on the M9 barrels are very generous and will accept boolits sized to .358 with no problem. They shoot well with boolits sized to .357 which is what I use for all my other 9mm handguns. No issues with leading have ever arisen.
It seems the boolits are being kicked hard enough by the 9mm pressures that they expand(obdurate) and fill the barrel nicely.

I have never run across a Beretta barrel that measures smaller than .357.

I see no reason a shortened barrel would not work properly in your compact and also an uncur barrel should work also. You will simply have a extra bit of barrel sticking out the front.
Many competition pistols do this as a matter of course since they often attach compensators or are ported in front of the slide. I had one of the latter for a time and it did make a significant difference in felt recoil.

Some of the barrels I have seen are a slightly smaller diameter back a little ways from the muzzle but my M9 barrels are the sane size all the way back, so should work fine in a compact pistol.

My Beretta 92FS barrel slugs out at .357. Frank

No. I needed .358 cast boolits in my former Beretta’s or keyholes appeared on target.

I bought a new 92F in 1988 and seldom shoot anything but cast bullets in it. I've never slugged the bore but have tried different diameter bullets. .3575" -.358" works best; good accuracy and doesn't lead. Bullet hardness in about the 12-15 BHN range has been ideal.

There are aftermarket barrels which are likely to be cut to the book value for groove diameter. Does anyone have a KKM, Jarvis, or other match barrel on their B92, and know their groove diameter?

The explanation I have heard for the large groove diameter is that it lets gas blow by at the point of maximum pressure, achieving a lower peak pressure.

My P38 barrels are the same way.

Since you mentioned KKM barrels, I remembered that Y owned one for a time.
It was cut to nominal dimensions(.355). It also had a very tight chamber. Boolits sized to .357 would often fail to chamber fully depending on the thickness of the brass.
It shot well but, really, not any better than the Beretta barrels I had.

Devil nailed it, use .358 or .359 bullets for a .357 and your problems should disappear.

Lee makes a good 125 gr .358 that with my alloy casts .359 or .3595.

Keyholing on 2 guns went away and group size shrunk dramatically.

Beretta M9, purchased new 10-12 years ago. Slugs at .3575. I’ve found .358 cast shoot acceptable. These are powder coated and left unsized. Haven’t done a lot of load testing or accuracy trials. Someday maybe. Right now it’s used for plinking and steel plate targets.

My Beretta 92 FS ran .357" when slugged. I sized to .358".

I built a comp gun on the Taurus to shoot 160 grain 38 Super hard cast RN bullets. The Taurus had a supported chamber and a Browning style left side frame safety, with a threaded stud through the trigger/sear actuator lever it was easy to make it into a single action. The comp was a duplication of the old Ruger Standard Automatic Target comp.
With a real hard cast, the bullet took to the lands well, in major. Shot that gun for two years at the FIPT. The 9x19 major is no longer legal in competition.

Rapier----That thumb safety you mention is the main reason I prefer the Taurus to the Beretta. I like my handguns to work the same way as much as possible. The Taurus safety works the same as the safety on my 1911. I don't have to stop and think about which pistol I have with me when I start to shoot. They all work in the same manner.
The Beretta safety works backwards.
Having them all work the same way might just save my life sometime. You never know.