With the easy access to the gas system, and ability to change out the stock and grip, it looks like it might be a fun gun to cut down.  Yes, you would lose the choke system, but with readily available and reliable 9 round mags, it looks like it has potential!

do it, and post pics! i pondering the genesis 12 for my ar10 size/style 12 ga

Anybody?

VR80 SBS..... Dragn12.  The VR80 does lend itself to an SBS. A lot of work. Quite a few hours of very detailed machine work modifying and creating new components.
I had it to the range two weeks ago to get a feel for the recoil, see what muzzle rise was present in the no choke version. 8.5 inches barrel length, 10.5 with the choke adapter.
At this very short length, the barrel does not present itself to internal chokes. Several reasons for this.
So just a few pictures at this time. No details at this time except what you see in the photos.

https://imgur.com/a/8jyeLAK

VR80 Short Barrel Shotgun. 8.5 inch barrel.

Looks good!

Huh...just last week, I was told I was a fool for thinking about buying one of those.

Now I really want one.

After seeing Namsag's pictures - and having handled them in a LGS - I'm leaning even more towards buying one. I've been waiting for a chance to shoot one first before buying.

That didn't keep me from buying a couple hundred of the 9 round mags though. They were being cleared out for some reason. $5.

Attached File
Seeing this is almost painful.  Derya is the Turkish OEM for VR80

@Namsag

I can't stop thinking about getting a VR80 to SBS now. Care to comment on the reliability? Runs fine with the short/medium/long mags?

How about going into what it took to get it to run with that barrel length? I never mind doing my own machining. In the early Saiga days unpinned the barrel and pressed it out of the trunnion then I pressed the gas block off and redid the ports - and added one - to get reliability where I wanted it.

First ammo tried was 1145 FPS, 1oz load and that would not cycle, FTE every round. Next was 1145 FPS, 1 1/8 oz load. Still a no go. 1200 FPS, 1 1/8 load was at 80%. Final load test was 1300FPS, 1 1/8 oz and that was 100%.
All of the shells were 7.5 shot low brass rounds. I was somewhere that only 7.5 shot and above were allowed so no slugs or buck were tried.
The gas system was moved about 2.5 inches rearward. That required turning the barrel, changing the length of the existing diameters to allow the piston to travel the increased distance.
The area where the slide and original extension traveled on were also altered.
The slide with extension was cut and the extension was removed completely. A support collar/bushing was machined for support in the slide as well as bushed for accuracy. All dimensions held to within .001
The gas ports and the retaining split ring grooves were moved and re-machined at the proper distance for the change. Threads were added to the muzzle to support the external threaded choke adapter.

As you can see in the pics, the barrel is quite thick. Internal choking is not advised because the needed choke diameter would weaken the barrel. The barrel would end up with too thin of a wall at the old gas port location.
I deliberately undersized the gas ports because of the higher pressure closer the the chamber. The hotter gasses are a plus and should keep the system cleaner for a longer interval.
The gas ports will be opened about .002 more per port and that should end the FTE issue with 1200 FPS and maybe even the 1145 FPS loads. Goal was 1200 FPS shot loads.
This is the first one. At this point I'm satisfied at the overall performance of the exact changes I made. Only a slight change in the gas ports are scheduled.
I am considering using one of the available friction/wear coatings on the moving parts and the barrels exterior.
I admit this was a lot of work. Lots of sketches for a machinist. I was present for all of the machining steps. I have over 20 years experience as a toolmaker working in aerospace.
I will be working on reducing the added recoil. Just over 6 pounds weight I figure. Not much muzzle rise. Much less than expected. Credit given to the front grip as it allows a good hold on the business end. Don't like post grips.
I named it the Dragn12 as it is a fire breather. It was tested in the 8.5 inch configuration. No Choke.

Check out my 7" VR80 build in process 03/15/2024  Post 7" VR80 SBS Build.

Not a VR-80, XTR-12. UTAS was talking of a XTR-12 Gen 2 and abandoned it. I could have told them exactly what they needed to change to make them run great if they would have wanted to hear it. Give someone the title of 'Engineer' and they suddenly can't learn anything from anyone else. This one is 8" and It took quite a lot of work to make it run 1250 fps 1-1/8 oz loads with a 4" barrel extension and the Salvo 12. It runs 1330 fps 1-1/4 oz loads with no extension or can. Pretty much 3.75 dram loads or stronger with nothing added to the barrel.

A VR-82 (20 gauge) would be perfect for SBS.

I'm doing one and have my form 1 submitted but I expect this brace influx will delay approval.

I was able to get a spare barrel to experiment with before Rock Island sold out (more are incoming).

One could do an MK-12 430 clone relatively easily - Shaving about 5.5 inches off the gun - Leaving with approx 14" barrel+ a short (cut) shroud.

Advantages are:

1. You can use the existing shroud, and handguard (no need to get a biscuit rail joiner to hold it on the gun)

2. You can probably get cycling going by opening up existing ports if needed, your losing dwell time but also have some length to work with.

You can cut 5.5 inches off of the barrel itself approx 1.5" just ahead of threads for shroud/nut.  Interestingly this thinner section can easily be threaded externally for M22x.75 (Saiga pattern) chokes/brakes, etc. for more options.  

The MK-12 240 with its 8" or so barrel would be preferred, but this short version has the gas system moved rearward to allow more gas dwell time in a short barrel - this goes beyond my skillset for a DIY project.

With the spare barrel I might experiment to see how short one can go with the barrel using the original gas system and port size.  
Cutting it shorter means:
-you need to use a biscuit to hold the rail on but these aren't too unattractive.
-You lose dwell time/energy  to give enough energy to move the gas system back hard enough to operate.
-If it works it may only run on hotter loads TBD

Some pics of the MK-12 430 and MK-12 220  Note placement of gas system is different (look for chrome ring under handguard)

That looks really good.

I did finish mine.  I actually did two barrel lengths as I was able to get a 2nd barrel from Advanced Tactical.

The shortest length I settled on using the same length gas system as it comes with was 10.5 inches.

I was able to get it to run reliably at 10.5" with a modified Saiga Choke and opening the ports up to 1/8" (0.125")

Generally it was an easy conversion - just cut barrel and open ports. cut the hand guard and use biscuit joiner for the rail to keep it on (you cut off the barrel sleeve ledge that clamps onto the barrel and secures it to the upper.  

I theoretically could cut it a little shorter but this seems about right.

That looks great.

I was shooting my full size today and thought, this would be great with a shorter barrel.

What loads does it cycle reliably with at this length?

The lightest I have tried which work - are the Federal Bulk loads that are like 1300ish ft/sec I got a bunch of 250 rd cases at Walmart years ago cheap stacked deep.  I have yet to try these lighter loads without the Mod choke.  The Mod choke would certainly add back pressure which I'm sure aids the reliability on the low end.  It also adds some length, as its an external screw on choke - so it appears longer by about 2 inches or so. Most shooting with this has been Cheap buckshot of various kinds, cheap turkish slugs and Federal bulk.  I have not taken the choke off - I should probably try that to see what difference it makes - I would like a shorter look .  I'm going to get a reverse sleeve and see what that looks like - but that will remove choke which might make it not work on lighter loads.  Will see when I get time.

The gun has been broken in and polished a bit by using lapping compound and working the action, polishing surfaces and chamber area, etc.  I'm sure that all helps.  Most people that use the VR80 in competition say it breaks in after a few hundred rounds and runs most lighter loads after that - so the guns have to be worn in to smooth out in general to reliably run lighter loads.  So keep that in mind and also when we chop there needs to be a way to keep gas pressure up.

There are three gas port holes on the barrel - they were opened up a little and that did the trick seems to run most anything (Note again - I HAVE RUN THIS ONLY WITH THE MOD CHOKE)

Much shorter and you are getting very close to the factory (long barrel) gas ports and dwell time is limited and opening up parts is not going to help as much.

Derya (who makes it in Turkey for Rock Island) makes a 9.5" shorty version but is different in that it has its gas ports moved closer to the chamber and gives the system more back pressure in such a short length.  We can't seem to get that barrel in the US as Derya won't sell direct (has to go through Rock Island) who also won't import it.  Probably not a sporting part if its short (so Import it longer(18"+) and let us cut it down

I am thinking of getting another standard barrel while they are around and see if I can go another inch or two shorter (and cut off another section of rail) and opening the ports up even more - but might be a waste of time and resources so putting other projects ahead of this at the moment.

I will add a pic of the gun in the 13" configuration - I have two barrels for it.

one is 10.5 and the other is around 13" - The 13" allows you to eliminate the biscuit to hold the rail on and just use the barrel sleeve as a nut to hold the rail onto the upper.

It is probably more reliable with lighter loads this way but never compared it with a lot of testing - like the shorter barrel better just because.