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[jiffx2781]

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[tactical_tech]

My MDI set came with several issues, 3 of them I'd be able to fix myself but there are 2 that bother me so I'm sending it back.

1 - barrel won't fit the upper (I just tried freezing the barrel and heating the upper)
2 - BCG feels lose inside the upper, it rattles, I'm not sure how lose it can be without issue, but compared to my AR it is very loose. You can move it sideways with your fingers through the ejection port.

When I first saw the MS I thought of cancelling my MDI pre-order and ordering a MS, but MDI was promised to an earlier date. If I had vaguest idea of the issues and delays I'd have done it.

Are you returning yours for a refund or exchange? I still haven’t decided what I’m going to do with mine

My BCG seems to fit fine, comparable to my other ARs. Barrels are super tight though as well. Also my barrel nut threads on somewhat stiff the entire way, maybe the anodizing is to thick, I dunno.

I have some small marks in the magwell but nothing like the OP showed. Maybe ATRS will take it as a trade lol.

[Sqr]

The whole idea of having a screw and heli coil as the retainer for the upper is a terrible design.
Prone to stripped heli coil, vibration loosing the screw, etc...
Also the upper can still move forward a small amount due to the size of the hole if it not completely tight or loosens off.

As opposed to the hook and pin on the ATRS which will not allow this to happen.

Helicoils are routinely used in black rifle offerings. Here is an A2 Receiver extension so it’s not uncommon.

Attachment 266276

[cman]

I wonder if the magwell scalloping is done at the retailer after they receive the sets from MDI, and before they have them anodized....

[cman]

Helicoils are routinely used in black rifle offerings. Here is an A2 Receiver extension so it’s not uncommon.

Attachment 266276

Agreed, however not as the main takedown source.

[purplezuk]

Helicoils are routinely used in black rifle offerings. Here is an A2 Receiver extension so it’s not uncommon.

Attachment 266276

Using a single bolt in a shear load with a helicoil ( or without one) is a recipe for disaster.
When you clamp 2 parts together, there needs to be clamping done at both ends to prevent movement ( rocking in this case ). Because the rear of the receiver isn't bolted down, it will move and the bolt at the front will loosen. This is a very simple concept that the designer didn't take into account.

[AGrant580]

Helicoils are very common practice with aluminum I am a welder fitter by trade and have built a lot of stuff for Rolls Royce (all military contracts) and 6061 when heat treated (properly) and using a helicoil (property installed) you can snap a bolt off in the helicoil.... so if MDI does their part correctly there should not be an issue.... just my 2 cents

[Fordmam]

I preordered one from MDI when it first, thankfully I ditched The SLR after they continued to lie with the two week delay BS. They did that for about 5 months. Like what the f was that all about?

ATRS receiver set I can’t say enough good things. Just a very good product, very nice looking, and the customer service is just amazing. There is absolutely no comparison between the two. Heck even MDI don’t communicate with their dealers never mind their customers.

[Fordmam]

ATRS doesn’t employ woman in tight yoga pants to do their machining. MDI for the win.

[jiffx2781]

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