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The 5.7 x 28 MM stuff







DonTom

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#1
Today, I went to Scheels in Sparks. So first, I ask the sales guy if they have the new Ruger 5.7. I figured the odds were very very low. However, they had it and I was told they just got it in minutes ago. I was also told it probably wouldn't last until the end of the day. Well, I then told him it would not last another minute because I am buying it ($700.00).

But I got even more than I was looking for. They also had a CNMG MK57, which I didn't even know existed until today. So I bought it also ($1,600.00).

With sales tax and all, I am now $2,490.07 poorer than I was when I woke up this morning.

In my 5.7 X 28 MM collection, I now own:

FN PS-90
Two-FN FiveseveN hand guns (1 of each color)
AR-57 Rifle
Thomson Encore Prohunter (custom 5.7X28 barrel)

Master Piece Arms MPA57SST
CMMG MK 57
Ruger-57


Is there anything that I am still missing in 5.7 x 28 MM?

-Don- Reno, NV

57..JPG
 
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Kinoons

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#5
Very nice. I can’t bring myself to spend the asking prices on CMMG and Diamondback.

I believe that the 5.7x28 is a perfect bug out kit cartridge. It’s also a pretty good SD round for inside 100 yards. My fiveseven and SBR PS90 are my go to for my bad guy in my home response.
 

Kinoons

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#7
yeah the diamondback was recently announced. i dont think it has hit retail yet
 

DonTom

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#8
Let us know how the CMMG MK57 is.
I sure like its looks. As soon as I saw it, I had to buy it right on the spot.

But I am not sure when I will fire it.

First, I gotta find a scope or sights for it, it has no sights, just a rail.

-Don- Reno
 

DonTom

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#12
Let us know how the CMMG MK57 is.
I love it. So far, it's my favorite of all. But I guess it should be, it cost even more than my PS-90.

The CMMG 5.7 is much like a miniature AR-15 pistol. Comes apart the same way and such.

I just purchased a binary trigger. Other than the magazine well, it all looks like an AR-15 lower inside, so I assume it will work. If not, I have several AR-15's I can use the binary trigger with.

-Don- Reno, NV
 

SixshooterSam

What, me conspiracy?
#13
I love it. So far, it's my favorite of all. But I guess it should be, it cost even more than my PS-90.

The CMMG 5.7 is much like a miniature AR-15 pistol. Comes apart the same way and such.

I just purchased a binary trigger. Other than the magazine well, it all looks like an AR-15 lower inside, so I assume it will work. If not, I have several AR-15's I can use the binary trigger with.

-Don- Reno, NV
Which binary trigger did you get? I've been wanting to try one, but by my research the Franklin Armory one is the only one worth getting. I'd be curious to hear how yours works out for you.
 

Janizary

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#14
I'd be curious to hear how yours works out for you.
Sam, I've got both the Fostech Echo II and the Franklin.

Functionally, the Franklin is (to me) crisper and lighter than the Fostech AND I can use it will a AR22 upper. That said it is super easy to outrun the trigger with the Franklin. I kept thinking I was getting FTFire, but finally realized I was just outrunning the trigger. (Or, perhaps, outrunning the carrier is a better way to put it)

The Fostech Echo II is a bit spongy, and cannot be used without a full-auto .22LR carrier on an AR22 upper. That said, I have not been able to outrun the trigger on the Fostech. Don't think it is mechanically possible to do so. I cringe every time I look at the hammer. It looks like it was cast by a 5 year old with a play-dough mold. I keep expecting it to snap off at some point, but it keeps running. Also takes a bit of gymnastics to put the upper and lower together as you have to push in a part on the FCG, hold the trigger down, then snap the upper and lower together.

EDIT: Fostech does sell a 'sear trip kit' for their trigger for their EchoII and Sport. https://fostech.us/22-caliber-sear-trip-kit-for-cmmg-22-conversions-and-uppers.html
 
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SixshooterSam

What, me conspiracy?
#15
Sam, I've got both the Fostech Echo II and the Franklin.

Functionally, the Franklin is (to me) crisper and lighter than the Fostech AND I can use it will a AR22 upper. That said it is super easy to outrun the trigger with the Franklin. I kept thinking I was getting FTFire, but finally realized I was just outrunning the trigger. (Or, perhaps, outrunning the carrier is a better way to put it)

The Fostech Echo II is a bit spongy, and cannot be used without a full-auto .22LR carrier on an AR22 upper. That said, I have not been able to outrun the trigger on the Fostech. Don't think it is mechanically possible to do so. I cringe every time I look at the hammer. It looks like it was cast by a 5 year old with a play-dough mold. I keep expecting it to snap off at some point, but it keeps running. Also takes a bit of gymnastics to put the upper and lower together as you have to push in a part on the FCG, hold the trigger down, then snap the upper and lower together.
Really? I thought it was the other way around, that the Franklin Armory unit was the only one that couldn't be overrun. That's why I was focused on it.
 

Janizary

Geth Prime
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#16
You can definitely outrun the bolt on the Franklin. I have some experience with outrunning it, a lot ;)

I have yet to outrun the Fostech II. Please note, that is the Echo II; I have zero experience with the 'sport' model.

Here are a few random folks with similar experience.

https://www.reddit.com/r/guns/comments/8wuyz2
https://www.reddit.com/r/Firearms/comments/aa5w0k
https://www.ar15.com/forums/ar-15/New-Fostech-binary-/118-737218/

https://thefiringline.com/forums/showthread.php?t=602742

You can mitigate the hammer follow on the Franklin with various options.

Again, just my anecdotal experience. By no means and expert. I got some good feedback on hammer follow from other forum members here a bit back.

EDIT: Huh, I had no idea linking reddit stuff would bring in the actual article portions.
 
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DonTom

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#18
I am now wondering if the binary trigger will be safe in my CMMG 5.7. The bolt in this thing is about half the size of an AR-15 bolt. Doesn't the bolt have a lot to do with how the binary trigger works?

Would I be better off just to install it in one of my many AR-15s?

-Don- Reno
 

SixshooterSam

What, me conspiracy?
#19
I'm still learning about binary triggers myself.. haven't gotten a chance to see and inspect the inner workings of one up close. Considering it's a somewhat expensive "toy", I'll be doing some more research before I eventually make a decision on which one to get.
 

Janizary

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#20
I am now wondering if the binary trigger will be safe in my CMMG 5.7. The bolt in this thing is about half the size of an AR-15 bolt. Doesn't the bolt have a lot to do with how the binary trigger works?

Would I be better off just to install it in one of my many AR-15s?

-Don- Reno
You can always just ask CMMG if it will work in their product. They may give the default 'no modifications are recommended', or give an actual answer.

I do know for the Echo II it requires a full auto carrier (more specifically, the portion at the 'rear' of the BCG, see image) to run. If the CMMG does not have it, then the Echo II will not work.



The Franklin, on the other hand, does not and I'd guess would probably work.

Does your carrier in your Banshee look like this one from Mrgunsandgear's review?
MK57 carrier.jpg

If so, looking at the profile on that carrier that looks like a fall-auto profile (ignoring all the lightening cuts). That said, I really have an idea of scale compared to a normal BCG from his review.