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The 5.7 x 28 MM stuff







Kinoons

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#42
More rounds to fire in smaller magazines with a bit less noise and the same round for smaller pistols and riffles are the only legit reasons I can think of. But I also have AR15s as well as many types of 22's to fire. In handguns as well as rifles.

While there are AR15 pistols that use the .223 / 5.56, I have never seen a small AR15 pistol.

Isn't the 5.7 by 28 MM the thinnest center-fire round? That's probably the main reason why I like it.

I don't expect to use it in combat! But I do have 500 rounds of the military & police (FN red box SS198LF) ammo for it, that I never expect to open.

I also have around 850 rounds of sporting ammo (Blue Box FN SS197SR) to waste with my new binary trigger. @ Sixty cents per round for when I am in the mood of wasting a few bucks out at the range.

-Don- Reno, NV
Don’t get me wrong, I love the 5.7x28 as well. It’s just limited in its practical (outside of range fun) applications.

I find the P90 to be ultra cool. Wishing I had full auto aside, my SBRed PS90 is absolutely my most favorite gun.

35F423F7-ACF3-4079-B509-3A2FE059A3D2.jpeg

That alone is enough reason to have one.

For CQB it’s a good round. Especially if your platform is smaller or lighter than an AR15. Keep the package smaller and lighter still (fiveseven handgun, ruger 5.7, my imaginary 10/22 in 5.7) and it makes a lot of sense for a survival round. You may be right, it might be the smallest diameter centerfire round. It blows away 22mag in both power (you get 22mag rifle performance from a 5.7 handgun) and reliability.

Edit - I also wouldn’t totally discount your blue box ammo for self defense. Somewhere between the 5” pistol length and 16” rifle length there is enough MV gained to penetrate soft body armor. I believe the 10” SBR can too.
 
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Kinoons

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#43
Price is now shown:

SKU: DBX57BGFB
MSRP: $1299.00
UPC: 810035751750



-Don- Reno, NV
Looks cool, but a street price of $1000-$1100 will still keep me on the sidelines. It is still too expensive to stick in a bag and forget about and not “better” enough than my current system.
 

DonTom

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#44
my SBRed PS90 is absolutely my most favorite gun.
Perhaps I will consider registering mine as a SBR and setting up mine like yours.

Is that a noise suppressor on yours? And where did you get you barrel cut and down to what length?

I have been considering making one of my rifles or pistols into a SBR.

BTW, just curious, can you do the suppressor and the SBR on the same tax stamp if registered both at the same time?

I never got involved with any Class 3 stuff as of yet.

-Don- Reno
 

DonTom

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#45
Looks cool, but a street price of $1000-$1100 will still keep me on the sidelines. It is still too expensive to stick in a bag and forget about and not “better” enough than my current system.
I just want to have everything made that is 5.7. Just collecting them as they are made, no logic involved. I have a few 5.7 pistols that I have never fired, but I have fired all the 5.7 rifles I own, which is only two, the PS-90 and the AR-57. Will soon be three, I am just waiting for my CMMG rifle upper to arrive. The last I heard it is out to be painted in the color I chose, Titanium. I already have the rest of the rifle done, with the binary trigger, just waiting for my upper.

-Don- Reno
 

Kinoons

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#46
Perhaps I will consider registering mine as a SBR and setting up mine like yours.

Is that a noise suppressor on yours? And where did you get you barrel cut and down to what length?

I have been considering making one of my rifles or pistols into a SBR.

BTW, just curious, can you do the suppressor and the SBR on the same tax stamp if registered both at the same time?

I never got involved with any Class 3 stuff as of yet.

-Don- Reno
the PS90 gets cut down to 10.5” - same size as the regular P90. Matt Babb did the work on mine before he took bentwood to a completely private contract.

Yes I have a suppressor on mine. It’s a gemtech G5

As far as the NFA stuff goes, it depends.

If you cut the barrel down on the PS90 and then perminately affix a suppressor that gets you over 16” of barrel total i believe you only need one stamp. Otherwise you need two stamps, one for the SBRed PS90 and one for whichever suppressor you purchase.

The nice thing about a form 1 SBR PS90 is you get to keep your current rifle and enjoy shooting until the stamp gets approved. You may also get the suppressor approved before the form 1 (not likely, form 1s go pretty quick) and could use it even on a 16” rifle.
 

MAC702

LEGEN...wait for it... DARY!
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#47
...If you cut the barrel down on the PS90 and then permanently affix a suppressor that gets you over 16” of barrel total, I believe you only need one stamp. Otherwise you need two stamps, one for the SBRed PS90 and one for whichever suppressor you purchase.
Correct. An integrally suppressed barrel that is over 16" has no need for SBR stamp. The rifled bore length is irrelevant.

We had a shooter at a Steel Challenge match that was using a highly customized Ruger 10/22 for the rimfire rifle division. It actually had only a 5" barrel with a tube welded to it for a 16" "barrel" length. It was absolutely the lightest rifle I've ever shot.
 

nlvmike

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#48
Kinoon has a bit more experience than I do, but I have a bit of data from shooting a lot of my reloads through a chrono out in the desert.

Out of my FsN, the blue box SS197 averaged 1,704 fps. I have the older round trigger guard IOM that shoots like a dream. The same ammo averaged 2,158 fps out of my 16" PS90. I loaded a lot of different bullets with a lot of different powders. The best I got out of the pistol was 1,668 fps. Too much work to "almost" match factory performance.

The real fun came shooting the EA S4M ammo. I got 2,419 fps out of the pistol and 3,105 out of the PS90. Great stuff, but too pricey to shoot much. I still have about 90 rounds, for Armageddon.

I can't recall either gun ever jamming with blue box ammo. The both jam often with American Eagle or reloads. I no longer shoot either of those.
 

pc911lv

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#49
Maybe same reason for 9mm over .45: magazine capacity.

My big question is, how is the bullpup trigger on it?
Ok I’ll give Mac the answer he is looking for. Yes it’s a bullpup and yes it does have a mushy trigger. But it is a lot crisper than most other bullpup, and Mac you know I have quite a few bullpups. Also once you get used to it it’s just like anything else. Only difference is that its like .45 a round to get used to it.
 

Kinoons

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#53
The cmmg banshee upper that can be used on any AR upper has some interest. AR style mags holding 40 rds. SBR/pistol around 7-8” and keep it light weight, like under 5 lbs, and you may have a good bugout/survival bag gun. Yeah the ammo isn’t available everywhere but you can carry 250, even 500 rds without breaking your back.
 

DonTom

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#54
Well I'm glad that binary trigger worked out for you!
Well, it does have an intermittent problem. A couple of times, it only fired a single shot. Even from semi-auto before I tested it in binary.

In fact, it was a single shot on the very first round I fired at the range. Was very disappointing. But mostly okay after than but still some jamming up occasionally.

I think I have slightly too strong of a buffer spring to get the bolt all the way back all the time. But it does work most of the time as is.

I had several weaker buffer springs with me that I was going to try to change while there, but then the winds picked up like crazy just before the rain came, so I got out of there ASAP. I put in the strongest spring in when I put the rifle together and it seems to be a bit too strong. I think the spring is just a little too strong, but it works most of the time, just not perfect--even in semi.

So it will take at least another trip to the range and another $100.00 worth of ammo to see if I can get it perfect.

BTW, it makes a lot more sense to put binary triggers in a .22 rim fire or some other cheap round!

-Don- Reno
 
#55
Don if you aren't going to reload your brass, would you try to save some so that I can fiddle around with it?

I was just given a set of 5.7 dies - and this can be one of those dangerous tipping points for a fellow like me, where when presented with a set of dies and some brass I eventually end up needing something to fire it from.
I have the reamer.

I'm considering making a 5.7 cylinder for a Single Six...
 

DonTom

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#56
Don if you aren't going to reload your brass, would you try to save some so that I can fiddle around with it?

I was just given a set of 5.7 dies - and this can be one of those dangerous tipping points for a fellow like me, where when presented with a set of dies and some brass I eventually end up needing something to fire it from.
I have the reamer.

I'm considering making a 5.7 cylinder for a Single Six...
Sure. I have around 300 or so 5.7 brass cases right here, from several years ago. That's from when I fired my AR57, with a bag to catch the brass. That is probably the best way to hold on to your brass.

I see you're north of Reno, wherever that is. But I could take a ride up to meet you somewhere with the brass, if you wanna. If you're much north of Cold Springs Valley/ Bordertown then , you're in CA! I am in Cold Springs Valley a lot as I own a house there, but right now, I am on the very top of University Ridge.

-Don- Reno, NV
 

Janizary

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#58
I think I have slightly too strong of a buffer spring to get the bolt all the way back all the time. But it does work most of the time as is.
Yeah, if it is not cycling far enough back reliably it could be a spring issue. I'm not sure and how the radial delayed blowback (those are radial delayed blowback (no gas), right?), impacts how much energy is left for cycling. Is there a recommended buffer weight for running that upper?
 

DonTom

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#59
Yeah, if it is not cycling far enough back reliably it could be a spring issue. I'm not sure and how the radial delayed blowback (those are radial delayed blowback (no gas), right?), impacts how much energy is left for cycling. Is there a recommended buffer weight for running that upper?
No recommendation that I am aware of. But even if there were, it probably wouldn't agree with the binary trigger, so I will experiment until I find what works best.

Yeah, I see no gas tube in this upper, so it must be using blowback. Anyway, I really didn't expect it to be perfect the first try. I just now put in my weakest spring and I will see what that does. I am going back to the CC range, headed out in a few minutes. The heavy winds cut it short yesterday, I was going to try out different springs yesterday while on the range.

I have two more springs to try that are more medium. But when one extreme gives me a problem, I try the opposite extreme next and see what then happens. Perhaps I will now be able to outrun the bolt, but I have two medium springs I can try that I am bringing with me.

-Don- Reno, NV