Anybody have any first hand experience with the Mini in .300 Blackout.
Most of what I've read has been positive regarding reliability but a mixed bag regarding accuracy.

We have them at work for sale . I have not seen any interest in them in the 2 months I have worked there . Not sure what the magazine situation is for them .

They use the same mag as the Mini-14.  They are just laser marked with 300 Blackout. You do not want to fire a 300 Blackout in a .223 rifle, you WILL have a bad day.

Did not know they have them for sale, need more info.

A friend of mine has one
Very reliable but bad accuracy with Barnes bullets for some reason.

Funny thing is my AR in 300 was much more accurate with any ammo of his I shot

I have one. I enjoy it. It has been used mostly with reloads but I have shot a little bit of factory ammo through it to include the 120gr Remington ammo with the Barnes headstamp. Have no accuracy issues with the rifle with either subs or supers.

In truth, the 300 BO is best in the sub-sonic role.  Other than that, ballistically, the 7.62x39 is a better choice as it produces about 200+fps higher velocities in the 125grn class bullet weights and is available commercially in both 125grn class FMJ and SP hunting ammo at reasonable prices.  Yes, the 300 BO is a good choice for sub-sonic, heavy weight bullets, especially with a suppressor, but in actuality, no one uses suppressed ammo for much of anything but grins.  It's not legal to hunt with a suppressor in most states, and the performance on any 'game' other than thin skinned humans is marginal at best.

Do you own a firearm chambered in 300BLK?  I gather you don't from reading the above post.

The beauty of the Blackout lies with its versatility and not solely on its ballistic performance. What other rifle cartridge gives the shooter the ability to shoot lightweight supersonic ammo for hunting or heavy subsonic ammo for quietly banging steel or poking holes in water bottles? All this without doing anything other than changing magazines and possibly adjusting a gas setting depending on which firearm is being used.

Also, the 300BLK with proper bullet choice, will outperform the 7.62x39 at distance. The 7.62x39 is limited to only a handful of bullet choices as factory ammo. Slightly more for handloaders and none of them offer much in the way of ballistic coefficient. Bullets like the Speer 125gr TNT work very well in the Blackout. This bullet has a decent BC and at muzzle velocities of only 2200fps or so it is still easy to shoot out to 300 yards without too much holdover. It is relatively inexpensive so a handloader can make some decent ammo for cheap. Not as cheap as steel cased imported 7.62x39 but way cheaper than factory ammo.

As a hunting cartridge the 300BLK is best used on hogs and deer. This is true with the 7.62 too. Neither would be great for anything bigger. But there are some bonded bullets in the 110-120 grain range that will work well for hunting or defense in the 300. Most of the 7.62 ammo out there is made to meet a price point and not a performance standard.

The 7.62 is also limited in the choices of rifle. Other than some AK variants and a few bolt rifles the Ruger Mini-30 is about it. The -30 is a nice little rifle and is fun to shoot. It generally offers accuracy that you probably won't see from the average cheap AK. The limiting feature on the Mini-30 is the availability of magazines. 20 rounds is it and you'll only be happy with factory mags. That's true with the Mini-14 as well but there you can go up to 30 rounds if capacity is what you're after. With that said some people have reported good results with the Tapco mags. I have not tried these persoanlly.

The Mini-30 has also had a somewhat spotty record of light primer strikes with some of the cheap ammo out there. It seems Ruger has this worked out nowadays but that issue still pops up from time to time. An aftermarket hammer spring might be needed to fix this.

Another complaint on the Mini-30 is lack of a stainless steel option and/or chromed chamber and barrel in the tactical model. While corrosive surplus 7.62x39 ammo isn't as common as it once was it still turns up at gunshows, etc. Care must be taken when shooting ammo of questionable origin or corrision may occur in the barrel and gas system. Ruger should have chromed the internal parts!

I have both a Mini-30 and a -14 in 300BLK so I am not just posting my baseless opinion.

I'm not disputing the 300 BO's capability, it has it's place.  However, it's a fact that it was designed specifically to be a 30cal, heavy bullet, sub-sonic rd for an AR platform.  Nothing wrong with that as it does what it was designed for well.  The OP was asking about our thoughts on a caliber in a Mini, not a AR and as Ruger already makes the Mini-30 as well as the 300 BO, he's entitled to hear thoughts on both calibers, despite your 'fanboy' defense of your 300 BO.

What I'm said was true, is factual, and is worth being told despite your objections.  If the OP isn't interested in sub-sonic, suppressed performance in his Mini, then the 7.62x39 is likely a better choice for him as cheaper blasting ammo is available and quality supersonic ammo, both fmj and SP for hunting is also available.  If the OP is a handloader, then he may appreciate the ability to tune up a bunch of different 300 BO or 7.62x39 loads, however, if he isn't then the 300 BO guarantees that he's forced to shoot expensive ammo as that's all that is available.  The 7.62x39, on the other hand, would allow him to shoot a variety of budget ammo, Red Army, Golden Bear, etc. for blasting or plinking as well as excellent commercial fmj and SP ammo from PPU, etc., which costs the same as the 300 BO.

You are correct, I don't have a 300 BO, nor do I have a 7.62x39 either.  I just commented on the ballistic performance of 125grn loads for each caliber and the fact that the 300 BO's good performance as a sub-sonic, suppressed rd may be of marginal or no value to the OP.  Many of us have no interest in sub-sonic, suppressed shooting.  Further, I don't have any bias towards or against either rd, just the knowledge of the fact that the 7.62x39 shooting a supersonic 125grn class bullet produces 200+fps higher velocities.  Nothing magic about reading reloading manuals, shooting friend's rifles in both calibers, and generally understanding ballistics. 

Edit to add new Hodgdon's Reloading data:  It seems that the velocity performance of some new powder choices has narrowed the velocity gap between the two calibers so I thought I'd include the data for completeness.  Hodgdon's on-line reloading manual shows that their Lil'Gun (small shotgun and magnum pistol powder) produces 2,402fps with a 125grn bullet in the 300 BO while their CFE BLK produces 2,554fps with a 125grn bullet in the 7.62x39, a 152fps difference. 

Why don't I own either?  I produce a number of different 30 cal cartridges as I currently handload 30 Carbine, 30-30, 300 Savage, .308/7.62x51, and 30-06 among the 16 rifle and pistol calibers I handload.  So it's plain to see that neither the 300 BO or 7.62x39 would fill a need I don't already have filled.  Hence the reason I don't own one.  That said, I have considered adding a Mini-30 to my collection configured like my Mini-14 Ranch Rifle below as a 'just because' rifle but have a hard time justifying the expense of adding another new caliber.

No. He asked for feedback specifically on the Mini-14 in 300BLK and not what you think is a better cartridge. You assume he doesn't know anything about 300BLK and/or does not already own a Mini-30.

According to Kevin Brittingham, founder of AAC.
These were our original requirements for this caliber: Muzzle energy has to equal or exceed the AK-47. .30 Caliber projectile. Use unmodified 30 round magazines to full capacity. Use unmodified AR-15/M-16/M-4 bolt. Gas impingement system. Shoot super and subsonic. And one thing that was nice, but was not a ‘deal killer’, was non-adjustable gas system. Cycle all four ways – subsonic suppressed and unsuppressed, and supersonic suppressed and unsuppressed.