ATI Omni hybrid

[Wanabgunsmith]

Just bought this lower

a67.tinypic.com/2638rj9.jpg

Bought the lower at the LGS, got it home, assembled it and went to stick the upper on.
And the darn thing wouldnt fit! It was way off, tried to hammer it in there and got this

a64.tinypic.com/5k1qxf.jpg
Sanded off a ton from the front end for this

a68.tinypic.com/308a9gz.jpg
Still way to tight but i actually got the pins in.
Is anyone else having these troubles? Any thoughts? Any suggestions on a cheap/light lower?

[Zen Archery]

Dang. Get money back!

[plant.one]

send it back and get you an anderson.

[triehl27]

First off, sent the lower back.

Secondly after a re exam of the photo it doesn't appear that the lower "Ears" are actualy plumb. I mean the photo seems to show them kinda in a V shape after sanding.

Thirdly. I may NOT be your lower at all, it MAY be your pins are oversized.

[Wanabgunsmith]

send it back and get you an anderson.

So funny, i live in Ky, do most of my business for stripped lowers with them and love them
The only thing to note is that a standard grip screw will be to long for certain grips(bcm gunfighter) however its an easy fix by getting a shorter screw, or using spmething to fill the extra space like a nut or spacers etc i just used an odd nut that happened to fit and make it perfect. Still theyre cheap, effective and an excellent company

I took it to the range and the crazy thing kept bursting/doubling! I stripped it and put all the parts back in my anderson stripped lower and it works fine again
My only advice until i speak with their CS is to stay away from ATI. Take that for what its worth(pretty much nothing)

Stick with what you know
If it aint brok dont fix it
a66.tinypic.com/opz7e8.jpg

[Wanabgunsmith]

First off, sent the lower back.

Secondly after a re exam of the photo it doesn't appear that the lower "Ears" are actualy plumb. I mean the photo seems to show them kinda in a V shape after sanding.

Thirdly. I may NOT be your lower at all, it MAY be your pins are oversized.

Had it working, correct pin size just had other problems with the design not being milspec compatable
It probably doesnt go full machine gun when used with their uppers idk, but not a subsitute for milspec parts to work in tandem with your previously milspec system

[Dolomite_Supafly]

What kind of upper? I have seen a lot more cast uppers in the last 6 months than in the last 10. And cast uppers rarely fit well. The last upper I traded for was off by that much and it was cast.

It is almost like someone found a long, lost stockpile of them and is selling them.

What is the forge mark on your upper?

Not saying the ATI is t the problem but the problem lies between them so it could be either.

[plant.one]

if its bursting/doubling on you it HAS to go back, asap. especially if the internals work normally in a standard lower. its obivously WAY out of spec.

not only is it unsafe, but buy being in posession of it - you're officially afoul of NFA law - regardless if it was intentional.


i sure wouldn't want it in my posession for an extra minute longer than absolutely necessary.

[Wanabgunsmith]

What kind of upper? I have seen a lot more cast uppers in the last 6 months than in the last 10. And cast uppers rarely fit well. The last upper I traded for was off by that much and it was cast.

It is almost like someone found a long, lost stockpile of them and is selling them.

What is the forge mark on your upper?

Not saying the ATI is t the problem but the problem lies between them so it could be either.

This is absolutely true. But the upper is a forged milspec upper for PSA. I couldnt tell you who made it for them but they claim it is forged and it has the marks

@Plant, thats exactly what i was planning to do come monday. If my LGS wont accept it then ill contact ATI i guess

[mostholycerebus]

This is 'normal' for these lowers. I have a couple of New Frontier polymer lowers, which are run on the same mold. The way polymer is produced, shrinkage rates can vary and cause slight variances unless the temperature and humidity are perfectly controlled. Most of these manufacturers are not interested in creating the environment they should, so some bits are very slightly large.

The solution is a degree of hand fitting. You will need to slowly tilt the upper back and find where it contacts the lower, and slowly file there. A flashlight can help see where you have gaps vs contact. 15 minutes should do it. I have also experienced the rear top of where the receiver extension is inserted, it was 1/32 or so too tall and the charging handle would contact it when retracted. Again, a couple minutes with a file fixed it.

Some people dont want this degree of work on their lower. I build plastic model kits, so this was normal and kinda fun for me. A few competition-type folks also prefer these lowers, mainly for the weight savings but also because the hand fitment means a super tight contact between upper and lower, NO rattle period. The pins all hold very tight.

My New Frontier has been good for almost 800 rounds as a range-only gun. Dunno if I would take it anywhere I expected to throw it around, like in the field, but would trust it if decently cared for. Its has its good and bad points. Tennessee Arms is now producing a brass/polymer hybrid lower that is superior to these in every way, except weight.