5.7 Upper thread

[Stickman]

John was nice enough to let me borrow one of the 5.7 uppers that drops directly onto a standard AR15 lower. With the addition of a heavy buffer (included with the upper), all you need to ammo to get shooting this blow back weapon platform.

There are plenty of comments about the 5.7 ammunition, but I think if we look at it as a PDW caliber, and not a MBR, it makes more sense.

If anyone else has played around with one of these, I'm interested in their comments. If anyone has any questions, I'll answer what I can, but I make no claims of being an expert on this upper.


Here is the link to the review....
http://www.weaponevolution.com/forum...ted=1#post7065

[lmmmmm]

I shoot the FiveSeven pistol and I have no issues with 5.7 caliber.

There are optional high power loads produced by one company in the caliber that matches the original intent of the caliber capability. The loads produced by FN have been reduced in the 2 formats available commercially (ss195 and ss197).

How heavy is the front end with the ammo stored on top??

[Stickman]

With the shorty, it gives it a pretty central center of balance, so its not bad at all. I've done dry drills with a UBR, ACS, and CTR, and it feels good to me. The heavier backend carbines tend to always feel better to me anyway, so the UBR was a favorite, then the ACS.

[Alaskapopo]

With respect I don't get it. The round is anemic and about the same as a 22 mag. The ammo is expensive so its not really a good plinker unless you are rich. I just don't see the point unless you are a huge 5.7 fan. But then again I would have to question anyone who chooses this round for applications involving shooting anything much larger than a house cat.

[TehLlama]

For somebody who already owns a FiveseveN, or is looking to use one can on an SBR and a pistol, or arrangements like that.

PDW rounds being tied to their specific PDW weapon systems has been a limitation in the past (only buyers for those rounds are people with that particular weapon system, so ammo prices stay high).

That said, a stocked pistol arrangement (similar to the CX4) with the 5.7 round, CMMG extended magazines would get nearly the same job accomplished as a much smaller SBR.

This makes me wonder how easy an SPR AR15 conversion kit would be for the 6x35mm round...

[Stickman]

With respect I don't get it. The round is anemic and about the same as a 22 mag.

You've got to look at this as a PDW variant, not as a regular carbine platform. It obviously can't compare to a .308, but neither can a 5.56. This can't really compare to a 5.56 platform, though I know there are people who would argue that idea.

[Ryo]

Do you guys think this is worth getting? I don't really see ammo being a stopping issue since when I last looked up the prices, the 5.7 and 223 were both expensive. Besides I plan to reload my own rounds so that should push the price down.

Concept it look good, pretty creative to have the brass drop downwards to the mag well. I am still deciding if I like the look of it.

Only reason I'm looking at it is that I have few lowers, not enough uppers.. so looking at different setups.

[SHIHAN]

If I didnt have a PS90 to match my FiveSeveN pistol I would get one.

[Army Chief]

I very much like the 5.7 AR concept, even if I would probably prefer to own a PS90 if I was planning to invest heavily in this caliber. (If we're comparing the two in SBR trim, the diminutive FN is still rather hard to beat.)

Still, the 5.7 upper is obviously well-built and effectively integrated into the AR form factor, and while it may fall just a bit short on practicality (depending upon how one might choose to define that), it is unquestionably off-the-charts in the innovation and interest categories.

If I had even the slightest commitment to this PDW cartridge -- which I may, at some point -- I would definitely consider adding a 5.7 upper to my tool kit. For the price, it's an almost irresistable temptation for an unobligated lower. :)

AC

[Ryo]

Too bad the FN is pretty expensive. This AR-57 puts it in a price category that's pretty attractive.

[Army Chief]

I hadn't really factored-in economics, but you're entirely right: the 5.7 upper is available for a fraction of the PS90s street price, and you gain modularity in the sense that you aren't tied to just that platform if/when you want to go in another direction. Good point!

AC

[John Hwang]

Considering the AR57 upper comes complete with a monolithic rail system & BCG, it's pretty affordable.

[Ryo]

Hmm.. maybe I'll make a pistol lower with the AR57.. low kick, and I assume it's not needing a standard AR buffer & tube?

[John Hwang]

AR57 comes with it's own buffer. It works with carbine buffer tubes.

[Ryo]

So John, it's a must to have a regular cabine buffer tube, or can I put on a short tube?