This started when someone mentioned that a Tavor in 308 would be good competition for the RFB and that it would be a superior rifle to the RFB (which is probably true), then it was suggested that a Tavor in 7.62x39 would be better than the .223. I'm saying that the x39 would not be a good cartridge for a Tavor or any other modern manufacture high dollar semi auto because of the poor ballistics (accuracy and range) compared to the already available 223 and that shooting corrosive ammo through a rifle that cost close to $3000 is foolish. the only advantage I see x39 having is that it's cheap but if you want similar ballistics then in my opinion a Tavor (or any other) in 300 blackout would be much better caliber to build. At least then you have flexibility in your loads and can run anything from 110gr supersonic (which is comparable to x39) all the way up to 220gr subsonics which would be better if we could use supressors here but even without one they are quieter and they hit like a ton of bricks on a steel gong at 100 yards and also print some pretty tight groups.
Running corrosive ammo is pretty much turning your rifle into a disposable firearm as the vast majority of shooters aren't going to go through the process you do to properly clean their rifles immediately after shooting.
Ya, your cleaning process sounds great

, do you do that in the kitchen sink? bathtub? on the driveway? If I started cleaning my rifles in the kitchen sink I don't think I'd be getting much play from the wife anymore.
I'll stick to giving my rifle a quick wipe down, a shot of wipe-out, a few patches down the bore and then a few drops of oil.
7.62x39 is fine in a cheap rifle if you are just going to the range to make some noise and then come home and spend another hour cleaning up but for me I would never run that in a rifle that cost over $2000 and since it was brought up in regards to a Tavor then we are talking about a rifle worth almost $3000. If you switch to higher quality ammo your not saving money over the .223 and the round has no category left where it shines brighter than the .223.
No one ever mentioned anything about bolt actions so I don't know where you got that from but I would put a bolt action .223 up against a bolt action x39 any day. Guess what? .223 is going to stomp all over it. Have you ever seen anyone using x39 in competitive shooting? There might be a reason for that.
Shooting position makes no difference as long as shots from either rifle are done in the same position and I guarantee no x39 is going to come close to a .223.
Why do I need to hit pop cans at 200 yards? Because I can and it's showing the accuracy which can be stretched out to further distances and still have the ability to make accurate hits on whatever I'm pointing at.
Hunting with x39? Sure, if your within 100 yards. Not only is the accuracy not good enough but the energy at extended ranges is dropping fast and you can not guarantee an ethical kill on a deer sized target much beyond 150 yards.
The accuracy potential of x39 is just fine. Its an INTERMEDIATE DISTANCE CARTRIDGE, its not designed nor was it intended for long range work. Again, it was designed specifically for iron sight rifles used to shoot people. An ethical kill is never guaranteed, there are plenty who hunt deer with a magnum which is completely unnecessary and yet they still have runners or need more than one shot. Shot placement is the key to any productive shot, focus on skill set not hardware.
So yes a Tavor in 308 would be nice and would be great competition for the RFB but building a Tavor in 7.62x39 especially as a second offering on a rifle that isn't really know for accuracy would be a waste of time and money. It's fine that the Tavor isn't the most accurate rifle out there, it's a battle rifle and as long as it's reliable and can remain in the 2-3 MOA range it's fine but running a round like the x39 would probably turn it into a 6MOA rifle which is just an expensive SKS and not worth the money. I'm actually very surprised Rob Arms has sold many XCR's in x39 for the same reasons, the rifle is too expensive to be running garbage ammo through and there are just so many better options out there.
Maybe in a few years when we have some other caliber options in these rifles it would make more sense to try and satisfy the small market that still want to shoot cheap surplus but if you can afford a $3000 rifle I think you should be able to afford to feed it quality ammo and at that point I want a rifle that can hit what I point at and can reach out to 300 yards and still hit consistently.
I think the large appeal to a Tavor in x39 is the availability of cheap ammo. If I had my choice, x39 isnt it, 223 is the better option.