What I would do is go ahead and register the lower receiver as an SBR per ATF. Assemble an SBR upper in barrel length of choice. Run a can, or not...I wouldn't be concerned about a suppressor on an SBR..they're not that hard on a quality device like the AAC. Then, I'd also get a 16" plus upper for the SBR receiver and if I were going out of the state and didn't want to do a form 5320.20, I'd just slap the long-barrel upper on the lower, screw the suppressor on it and go on out of town (making sure not to "retain control" of the short-barrel upper - IOW don't take it with you).

The suppressor is registered separately as a stand-alone item. It's not part of any particular firearm so it can be interchanged between rifles at will with no illegalities. Long barrel, short barrel, multiple rifles...whatever. All legal.

The receiver might be registered as an SBR, but if it has a long-barrel upper on it, it's removed from ATF purview (no longer an NFA item) as long as you don't "retain control" of the short-barrel upper. The phrase "retain control" is a little fuzzy, but the ATF interprets it to mean in proximity to the gun such that it can be installed right away. And, of course, there's the practicality issue. You're not going to accidently bump into an ATF agent who would then run your rifle's serial number. He'd have no reason to. As to local law enforcement, it depends on the state, but states that don't specifically state that the SBR has to be NFA-registered removes it from the jurisdiction of non-Federal law enforcement. As long as it has a 16"+ barrel on it, you could take that NFA-registered SBR to any state where AR's are legal.


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All true, but I don't feel a need for an SBR. The shorter the barrel/gas-system on an AR, the worse it performs, in general.

Once you get below about 11.5 inches, gas systems can get a little finnicky due to the decrease in dwell time. An 11.5 inch SBR has about a 40% greater dwell time than a 10.5, so 11.5 and above---no problem. Add a suppressor, things can get a little more complicated, solved with an adjustable gas system like the Switchblock.

As to performance, I lose about 250 FPS with my 11.5 compared to my 16 inch using PMC .223 ammo in 55 gr. Since my SBRs are entirely for shooting at 50 yards or less, there is no meaningful performance degradation for my purposes. YMMV. For those who want a rifle to shoot out at 100 yards and beyond with MOA accuracy, an SBR wouldn't be the best choice.




That, of course, is the bottom line. The reason I persist on the subject is that I wouldn't want anyone to get inaccurate impressions.


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I have seen a lot more people with baffle-strikes on the <14.5" guns, though. Further, gas-port noise is enhanced greatly.

I just don't mind the extra barrel length and the CDI factor isn't enough to make me pursue it.

An SBR can be very accurate at 100+ yards, though. Don't limit yourself to 50 yards.

As to your point:
-Yes, 10.5-11.5" guns are reliable with a can.
-The new SOST ammo (tested some the other day, love it!) was designed to function out to 100m from the 10.5" barrel.
-No SBR's are not less accurate.
-You need a brake instead of a flashhider if you run a SBR and a can. Your can will thank you and the blast baffle will last a LOT
longer.
-The shorter the barrel, the more you need an adjustable gas-system (like the Noveske SB. Speaking of which...where can you buy replacement gas-tubes for that thing?)

I limit myself to 50 yards with an SBR because I'm not interested in shooting farther, not because the rifle can't hack it. As you note, they can be very accurate if you use a quality barrel. I do sight in my red dot sights from a sandbag rest with a 3x magnifier, but otherwise I never use the magnifier nor do I shoot from the bench. A 3 inch group at 50 yards is completely acceptable to me. For my purposes, if I can put two in the chest and one in the head from 50 yards on a 3-D paper target while moving...that's my Holy Grail. SOST ammo is techically interesting but irrelevant to my needs and would/will be unnecessarily expensive in the volumes that I shoot.

I don't worry about suppressors because I can't use them anyway (illegal). I do use brakes on all my rifles (BattleComps). They're great.



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Are you guys talking about gas impingement or piston ar15? Or it doesn't matter?

That sucks. Where do you live?
I like the SOST stuff. It's good to have a few rounds in the wings. Other than that, XM193 is good enough for me and plenty cheap.

EDIT: Changed my order from an M4-2000 to an SPR/M4 in the nick of time!

Stickied. :tup:

Minnesota. The DNR is an inordinately powerful organization here and they have persuaded the legislature that if suppressors become legal, everybody would be out crawling through the woods poaching deer and the DNR would never know because, of course, a suppressor turns a loud rifle report into nothing more than a pffft.:rolleyes:

I'm not sure I see the advantage of a gas piston on the AR platform. A friend of mine has started a line of gas piston guns (Huldra Arms). It's a very nice weapon, but I haven't yet bought into its superiority over direct impingement.

Same. DI is what the entire weapon was designed for. Piston systems place stress on components not meant to be stressed. IMO they are worthless, as the junk in the weapon also comes back up the bore on a suppressed rifle because the pressure in the can has not equalized by the time the bolt un-locks and you get blow-back through the barrel.

Changed my order from an M4-2000 to the SPR/M4 at the last minute btw : )

Is the Ruger SR556 above reliable?

AFAIK, mixed reviews. It's a pretty well-designed rifle, some components designed from the ground up for gas piston, but others conventional DI. They are prone to carrier tilt, like most piston guns, and that does cause more wear on the buffer/tube. Of more concern would be the reports of malfunctions in various positions. I keep hearing of failure to feed, for example, when the gun rests on the magazine butt (as in prone shooting). Also, failure to eject in rollover prone. My general impression, never having fired one, is that they're "OK" as far as piston guns go. At that price, if I were going to buy a piston gun I would definitely go with a Huldra. That gun is made for that private label by Adams Arms. Huldra did mandate several modifications and upgrades. They put over 4000 rounds of 5.45 through one of their rifles without any cleaning nor any lube...no maintenance of any kind..without any malfunctions. They used 5.45 because they had a large stock of cheap surplus ammo.

The problem I have with piston guns is largely that you're paying about an extra $400 for the gas system, but certainly aren't getting $400 worth of advantage over a DI...some would say no advantage.

It's hard to separate fact from rumor when it comes to Ruger, and this is probably more true in the AR15 crowd. People that shoot those rifles have a little more of a tendency to be rabid Second Amendment fans and those folks have a tendency to believe that Bill Ruger tried to sell them down the river to Congress in order to keep the Mini-14 out of the Assault Weapons Ban. I always take Ruger criticisms with a grain of salt.

I just read a little while ago about Bill and Congress, I wasn't aware of his doings:mad:!
After looking more into Ruger, the price is too high. I'm checking out Bravo Company, prices are way more reasonable!
I know very little about "assault weapons". I just made my mind up yesterday that I want one! Were moving to Tenn., after the 1st of the year, "gun friendly state"! About the middle of next year, I should have enough $ put away for one!

Buy from BCM. They will sell you a great weapon at a great price with no BS.