I just discovered this product (Unimag - Ross Defense) and the 2014 thread but little more (I'll keep searching).
It is an intriguing product - do they work and are they GTG?
Thanks for your input.

If it's the one made by member Longziz ( sp?), my prototype worked flawlessly. I know a few didn't, but most did. That was the prototype stage though and early testing. I never bought one as I actually had a lot of things going on and forgot I even had it. I only own one caliber now so I don't have need to buy them.

Prototypes worked great.  Gen 1s worked but only if your magwell was a porn star.  Gen 2s work fine & I've run .223 and 7.62x39mm through mine.

I bought a couple. They have worked so far with 223, 6.8 spc, and 7.62x39 in my ARs.

Had three about a year ago.

They went into the trash on the first range day.

I bought them for 5.45x39.

If I could force them into the rifle they would just jam every round for some reason.

Best guess is that they weren't actually fully seated but I was so mad at the time I just tossed them.

Last gimmick mag I ever bought.

5.56, 6.5 Grendel, 300 BLK, 458 Socom

Use unimag to run 7.62x39 and 5.45. Been 100% dependable so far.

ok, serious question here...

is this really a good thing?

doesn't it increase the chances of grabbing a magazine with the "wrong" ammo loaded in it and trying to shoot it down the wrong chamber/barrel?

wouldn't you really need a UNIBARREL to go with it... ?

We already have that issue w/ .300 Blackout in ordinary mags.  The other cartridges don't mix & match in the chamber, so it's a non-issue.

it's been my experience that "one size fits all" really doesn't fit anything perfectly.

and since you dont see the entire world switching over to them, I'd suggest it was a solution in search of a problem.

Everything's a compromise.  I think the largest hindrance to widespread adoption of the Unimag is the price.

I just picked up 5 of what are supposed to be the second generation mags from Tactical Shit. The box arrived this weekend, but i haven't even opened it yet because the last couple of weeks have been an amazing sh!tshow. I'll get a chance to at least look at them this evening. I'll be trying them with 6.5 Grendel, 7.62x39, and .300 Blackout. Couple of months I'll probably add one of the big-bore cartridges to that list, which is why I ordered them. Minimum 4 different calibers from the same set of mags was too good to pass up. If it works.

John

Yeah, so I ended up going upstairs and trying them in 4 different ARs. 3 are built on Anderson lowers, one is a dedicated 22LR on a New Fronteir polymer lower. Obviously the mag isn't for 22LR, but it's still a "milspec" dimension lower. Or so they say.

The magazines go into all 4 lowers without what I would consider undue force. They lock in place. On the lower for my .300BO and the New Frontier lower, the mags drop free upon release (empty). The other 2 they will pull free easily, but do not drop free.

I loaded the mag with 25 rounds of 7.62x39 Wolf 122gr FMJ. The mags still fit all 4 lowers, inserting without difficulty. They drop free from the NF and .300BO lowers, but still have to be pulled from the other 2. Still don't bind in any way, they pull free easily, but even with the weight of a fully loaded mag they don't drop.

My other lowers are all pistol caliber and won't take a full-size magazine. I have a friend that has a rifle I built on a Bushmaster lower that I can try the mags for fit in later. I'll update as I go. The real question is the feeding, obviously. It'll be weeks before I can get to the range just now, but I'll update on that when I can. Without dropping free, the mags are at best range mags. - Still an improvement on earlier reports.

PS. the product number ends -001B
I'm assuming the B indicates second generation.

Disregard

It's not a problem in the field army. There are not alternate cartridges issued, and you don't bother carrying weird ammo that can't properly chamber.

It's a first world problem when a shooter takes different guns using the same style of magazine and isn't careful with what he's doing. If you are blessed with the riches of having too many guns, then be blessed even further by marking the caliber prominently on them so you won't screw up. Headspace and timing of the operator is the cause - shooter created. Don't blame the hardware.

We get reloaders who more frequently than they want report they charged ammo with the WRONG POWDER because they got mixed up at the reloading bench. Best practices are to remove all traces of the previous blend and operate the charger until empty. Either that or live with kabooming your AR with pistol power and picking pieces of chamber out of your scalp and remaining fingers.

Don't play stupid games, don't win stupid prizes. Operate with the idea you WILL make mistakes and train to prevent them, not let circumstances exploit how imperfect we are. Too many think they can't make mistakes - which is an admission they are not ready for prime time. Adults know they can - and with that admission, they work to prevent them.

Mark your mags, keep your powders separated, don't be That Guy. Plenty post up every month here, it's the norm. Don't be normal. It's painfully expensive.

Says the guy with a titanium rod in his leg.