[WC145]

So, I've got an FN PS90 which is a great gun and I like it very much. However, as small as it is it's still a rifle and the law says that I cannot have a loaded rifle in my vehicle. A friend of mine who lives in AZ got a new Franklin Arms AR-15 pistol with their binary trigger last year, which is a bad ass weapon. When he told me that because it's a pistol he can keep it loaded in his truck the light bulb went on and I thought 'Hey! I can do that here in Maine, too'. Personally, I find the 5.56 way to loud out of a regular AR and they're ridiculous out of a 10" barrel. The 5.7x28, on the other hand, is only about half as loud and very accurate and effective out to 150-175yds. So my vision was an AR57 pistol instead, problem is ARFiveSeven only sells uppers and complete rifles, not pistols, and I haven't seen any short barreled uppers for sale.

Well, I got lucky recently and grabbed a barely use AR57 LEM rifle off gunbroker for $795 in the box with all the stuff, I just picked it up from my FFL today. It appears to be well made and the fit and finish are excellent, as is the trigger. My luck continued when I ran across stripped AR57 lowers on Bud's for $60 this morning and ordered one of them, I'll be able to just transfer all of the parts from my rifle lower into the new one and have my pistol lower. ARFiveSeven is out of stock on 12" barrels on their site so I've emailed them to find out when they'll be available, in the meantime I'm on the hunt for one in case my luck hasn't run out.

The final piece of the puzzle will be either a Fostech Echo or Franklin Armory binary trigger group, once I find out for sure which one functions with the AR57 upper. Until then I'll have to be happy with plain old semiauto. Either way, once it's put together it'll be shorter than my PS90, use the same 50rd mags, AND I'll be able to have it loaded in my vehicle. In addition, because of the LEOSA, I qualify to carry across state lines and since it will be a pistol it will fall under the protection of that legislation. This will allow me to take it with me wherever I go giving me range, accuracy, and capacity advantages I cannot match with a conventional handgun.

It's going to take a little while to gather all of the parts so I'll be trying out the AR57 in it's factory configuration and comparing it to my PS90 and posting my findings here for anyone that is interested.

Here are a couple of pics from the gunbroker ad, I'm working today so I haven't been able to take any yet.

 

[Raylan Givens]

That'll be like shooting a .22 Short.... I like it

 

[WC145]

Yeah, zero recoil, it's going to be fun!

 

[Jollyroger1]

Oh man that looks exciting!

 

[WC145]

Been thinking about the barrel issue, or the lack of availability of 12" barrels, and I'm going to check with a local gunsmith that has done a lot of work for me (he built my Colt .38 Super) and see what he thinks of cutting the barrel, turning down and threading the end then reinstalling the flash hider. The only issue might be the fact that it's fluted, depending on the depth of the flutes. I'm sure he could do it for less than the $175 cost of a new barrel (plus saving me the time it would take to find one) and I could probably have him strip the rifle lower and transfer everything to the new pistol lower while he's at it.

 

[LPRoad]

Should be fun, I've always wanted to try the 5.7.

 

[jaydoc]

Are the AR57 lowers designated as pistols? If not, you are building a short barrel rifle. Call it what you want but it might not be legally a pistol.

 

[WC145]

A stripped lower isn't designated as anything and doesn't have to be, it is listed on the 4473 as an "other" not a rifle, shotgun, or pistol. Since it's a brand new bare receiver it can be used to build whatever I want, a rifle or a pistol. This is why I ordered it, I'm starting with a fresh, serialized, bare lower receiver and building it into a pistol. Since it will be a pistol, I can have any length barrel on it I want. I can't do that with the original lower receiver because it is already a rifle and once a rifle, always a rifle, and if I were to put a barrel shorter than 16" that would make it an SBR and subject to NFA regulations.

ETA: Once it's built as a pistol, if I put a stock on it with a barrel <16" it becomes an SBR. That why the wrist braces have become so popular, an AR pistol is still a pistol even with a wrist brace mounted on the buffer tube.

 

[Sterling Archer]

Huh. That is pretty dang cool!

 

[awp101]

Interesting...

What makes the lowers at Bud's different? Just the caliber marking? I was under the impression a 5.7 upper worked on a standard lower.

 

[WC145]

Interesting...

What makes the lowers at Bud's different? Just the caliber marking? I was under the impression a 5.7 upper worked on a standard lower.

The AR57 uppers do work on any lower, the difference is that the one's that Bud's is selling are actual ARFiveSeven brand, like the one that's on the rifle now. I like the idea that the gun will have essentially the same lower that is on it now and fit and finish should be the same.

Bud's-

Mine-

 

[awp101]

OK that makes sense, thanks.

If we could get NATO spec loads the 5.7 would be very interesting to me and I might have held on to the PS90 I had 10 years ago or so. My understanding is what the manufacturers offer is closer to a reloadable .22 WMR than what the round was designed for. Still, this has the wheels turning since I've already got a couple of pistol lowers already...

 

[WC145]

I took the rifle out and shot it yesterday and I'm very happy with my purchase. I mounted a Vortex Strikefire II red dot on it that I'd bought a while back and was saving for just such an occasion. The sight came with a cantilever mount, battery, and flip up lens covers so it was ready to put together and bolt on. The rifle functioned perfectly and was easy to sight in. It has a pretty good trigger, a little creepy, but not bad. it functioned perfectly using a PS90 mag that I had ammo in and it was accurate, though a red dot is hardly precise once you're far enough away that the dot covers your bullseye. I used this ballistic calculator - http://www.handloads.com/calc/index.html - to work out trajectories for a 150yd zero, which has it zeroed at 35yds as well, and a dead on hold out to 180yds with less than 4" total rise/drop. At 35yds it was putting one round on top of another. I checked it at 75yds and was able to put 10 shots in a couple inches, not bad for zero magnification and shooting off the hood of my jeep. At 125yds (the farthest I shot it) I was still able to put them in 6" or so, plenty good for coyotes, foxes, feral cats, etc.. And, center mass hits on a silhouette out to 200yds should be easy as the bullet is only dropping about 5" at that distance. I don't think I'll lose too much velocity with the 12" barrel so results should be similar when the pistol is done.

Compared to my PS90, inserting a mag requires a little more attention because it doesn't have anything that helps to line up the mag like the PS90 does. Other than that, the PS90 wins on compactness compared to the rifle, but once the pistol build is done they'll be pretty even. I like the rifle and enjoyed shooting it, it gave me an idea of what to expect from the pistol when it's done. So, as much as I like my PS90, the AR57 pistol will be replacing it and I'll be selling the FN to cover the cost of this project. I'll update this thread with more pics when the parts have arrived.

 

[awp101]

Sounds like a winner that will do what you're asking it to do. Can't ask for more that that!

Dang it this is tempting pursue...

 

[WC145]

I just heard back from the ARFiveSeven folks and, as luck would have it, they have one 12" fluted barrel left stashed away so that'll be on it's way here soon and the lower will be here in a couple of days. Just have to decide on which AR "wrist brace" to order for it then I'll have all the parts for the conversion except the binary trigger. I had contacted Franklin Armory and they emailed me back but the only thing they said was that they hadn't tried their trigger with an AR57 upper, though I read a post somewhere that the author had issues using one with the AR57 upper. I also saw a posting by someone that used the Fostech Echo trigger in one and it worked, naturally I didn't save it so I'm hunting around for it now. I'll buy whichever works. Since the binary trigger isn't necessary for the pistol build I'm not to worried about it right now, I'll get the gun put together and order one once I've done all of the research.

 

[WC145]

So, I'm making some progress. I've rec'd the barrel, still need to get to my FFL and pick up the receiver, and I've ordered the Shockwave wrist brace kit. I contacted a 'smith that does a lot of work for me but he's swamped so it looks like I'll be swapping the parts from the rifle lower to the new stripped lower myself. I'm checking around for another 'smith to swap the barrel on the upper for me, I think there are a couple of shops around Bangor that do a lot of AR work so it shouldn't be too much of an issue. Had I thought about it I could've sent my upper to the AR57 Center and had them do it instead of having them ship me the barrel.:facepalm:

 

[WC145]

Finally got around to picking up my receiver and the Shockwave Blade kit arrived. I'm waiting on a couple of tools to get here and I'll be able to get things changed over.

Got things sorted on the binary trigger, turns out that the only guy I could find to talk to about actually using the Franklin Armory BFSIII binary trigger in an AR57 had issues with it. It would not function as advertised and Franklin Armory didn't have any answers for him. However, the Fostech Echo trigger group will work in the AR57 with a full auto bolt so today I took advantage of Optics Planet's black Friday discount and ordered an Echo trigger and will be ordering the new bolt next week when they're open again.
So, progress is being made on the project, slow as it is.

Here's a link to a video of an AR57 SBR with the Fostech Echo trigger. This rifle is very similar to what my pistol will be, same length barrel, etc. -

 

[awp101]

Here's a link to a video of an AR57 SBR with the Fostech Echo trigger. This rifle is very similar to what my pistol will be, same length barrel, etc. -

 

[awp101]

WC145, are you going to roll your own ammo or stick to store bought? I can hear a rifle upper whispering my name...

 

[WC145]

I don't reload any ammo right now so
I'll keep shooting factory ammo for the forseeable future. PSA usually has the 40gr FN Hornady V-Max for $18 a box of 50 and the 40gr American Eagle for around $15 so it isn't outrageously expensive and I keep a fair amount on hand.

Getting set up to reload is on my list of things to do eventually. Just have to stop putting the money into guns and other stuff, first!

BTW, I ordered the full auto bolt today. One step closer to having it done!