Does anyone have both or have a comparison/opinion on how they compare?

Would you choose one over the other for hunting deer/hog?

I'm mainly asking these questions for you all to convince me to buy a 7.62x39 RAR (not that I need any convincing at all), as I already have a RAR 300BO and am curious about more discussion on the x39. I just found out that river snuck this in on me about a week ago and somehow I still haven't bought one yet, as I'm a fan of the x39. I told my wife that the 300BO was for the kids as it has 0 recoil and is accurate as crap and just fun as heck to shoot. Everyone that shoots it falls in love with it. It's even taken the place as my favorite even over my American Predator in 308. I'm still trying to gain a liking to my America predator in 6.5 creed.

And I can't help but feel that I need to balance out my gun safe. 2 predators and only 1 ranch. That x39 would help balance it out!

As you're talking pig hunting, you're not looking at a suppressed load but rather 125grn class super-sonic ammo.  In that case, the 7.62x39 generates over 200fps higher velocities than a 125grn class 300BO load so it's a better choice as a hunting rd for pigs.  As you already know, hunting ammo prices are the same for both calibers. 

For example, PPU makes excellent brass cased, boxer primed 123grn SP ammo for both calibers at comparable cost on line.  In addition, you may already have some Red Army Standard steel cased, berden primed 123grn 7.62x39 fmj ammo (currently available for as little as 19¢ per rd at Outdoor Unlimited) that works well for practice and plinking. 

Nothing wrong with the 300BO, it's just that the 7.62x39 is a faster rd and a fine choice for pigs.  So, if you're looking for an excuse to get a RAR in 7.62x39, you've got all the justification you need.  Besides, with a second RAR, you can take one of the kids with you pig hunting.  Win-Win.

I'm a Ruger American fan as well, I own the 5.56 Ranch, 300 BLK Ranch, 7.62x39 Ranch, and the 18" .308 Predator. I like the 300 BLK with heavy subs suppressed, and I like the 7.62x39 suppressed with cheap ammo. Two different guns for sure, but I wouldn't hesitate to shoot a whitetail with a quality 7.62x39 soft point round. I won't shoot a game animal with a subsonic blackout. The 7.62x39 will feel just like your other Americans with one exception, the bolt will take more forward pressure to strip rounds from a full magazine. It is not a problem, it just feels different than chambering rounds from the rotary mag in the others.

Is the x39 a good host for a plinking suppressed gun? I'd prefer a 6.5G but this might just work.

It is for a supersonic plinking suppressed gun. Cheap ammo, mag fed, and my rifle groups great. I use soft plugs with all supersonic rounds, the sonic crack sounds close to the same for all comparable rifle cartridges. If you want a subsonic plinking suppressed gun get the 300 BLK Ranch. I got both!

The appeal over the 300 are the cases of x39 in the garage

The real appeal is that the 7.62x39 can be loaded with a 150grn subsonic rd just the same as the 300BO, but the 7.62x39, when loaded at supersonic velocities with lighter weight bullets in the 110 to 125grn range, produces significantly higher velocities than the 300BO.  Therefore, the 7.62x39 excels as both a a subsonic and supersonic rd whereas the 300BO's forte is subsonic.

The actual real appeal of 300 is fitting into an AR 15 without funky mags of questionable reliability. Performance isn't dramatically different than x39. Grendel excels at everything better than both of them. 

The only reason 7.62x39 has any appeal at all is due to cheap ammo. You might be someone who loads your own and loves the caliber for its charms and capabilities, but you're probably one of the few. Most everyone else just likes it for cheap but still powerful plinking. 

Sold my 300 blk RAR today , gonna pick up the x39 tomorrow .

Had a few issues with the crappy 300 mags . I need something 100% reliable this being my primary deer rifle & I only shot supers anyway ...

You think an American in x39 mags are going to be any better?

Op for hunting the 300blk is a a great hunting round.  Especially if you reload.  The x39 is a cheap plinking round thats it.

The x39 uses mini 30 mags. The 300 uses the crappy plastic rotary mag that everyone hates. So... Yeah, most likely you're looking at better functioning mags.

Zero feeding issues today with my new x39 RAR. Off to the woods tomorrow ...

Out of curiousity, how much did you sell yours for? Every time I think about picking up a used one, folks want as much as a new one.

I have a mini14 in 300, so I really want a 300 like the X39, one that takes mini mags, but I'd have figured they'd announce them all at once if it was actually happening any time soon.

I sold it to a buddy for $280

What kind of accuracy are people seeing out of the X39?

I have a CZ 527 in 7.62x39 and it is quite a shooter.   The rifle was expensive and I would have preferred to get something that could use larger magazines and was American made.   Figures that two years after I buy the 527 Ruger comes out with the RAR version.

I get 1.25" groups out of mine shooting Hornady 123gr SST's. I heard claims of 1" or less groups from guys on the internet. In my opinion, those are either 3 shot groups or some tall tales. Been thru ALOT of different types of ammo in mine and that's the best I can do. But, I am quite happy with those results.