DI or Piston for SBR 10.5" barrel?

[dtibbals]

I am brand new to SBR and plan on buying one this summer. I have all Noveske rifles in my safe now and intended to buy another one from them for my SBR 5.56 10.5" barrel. I plan on running it pretty much all the time with an AAC M4-2000 suppressor. I would order it with the switch block but was wondering how reliable that set up is? Would it be better to purchase an LMT or LWRC piston upper with that short of a barrel?

I used to own an LMT piston 16" and it was a great upper but found that in a quality rifle with 16" barrel the piston really wasn't of much advantage.

So piston or DI for an SBR? Which is the most reliable?

Thanks
DT

[Javelin]

I spent so much time making the decision as to whether or not to go piston for a 10.5" SBR.

In the end I ended up with 2 Noveske SBRs (5.56 & 300BLK). The 5.56 has a switchblock and both have functioned flawlessly. So I guess I chose right?

:D

[C-grunt]

I believe the conventional wisdom is SBR suppressed and full auto. If you are doing all three a piston should be considered.

[R0CKETMAN]

I've been running a 9.25" piston suppressed for a couple years now. I'm also using a DI 7". Both run, both get dirty, both give me a gas high.

[viperashes]

I personally run a PWS MK 110. The limited time I got with it before heading back out here to AFG had it running great suppressed and unsuppressed.

Ultimately, if you go with a quality FACTORY built SBR upper, it shouldn't ever give you any major issues, as long as you're using a standard spring and the correct buffer.

[Moltke]

There is no reason that you "have" to go piston, in fact, many consider it NOT to be superior to a DI AR anyway. A piston rifle keeping a receiver clean is a matter of convenience, not a matter of functional or design superiority in the weapon system.

[markm]

Piston is good for NOTHING in the AR realm.

[Tzook]

I have the Adams Arms piston on my gun, and they have a nice feature for adjusting gas output or levels or whatever for suppressed fire.

[Moltke]

Since we're on the subject -

Let's say you're buying a Colt rifle which is built to a very specific spec, with testing done to assure any buyer that the rifle meets that spec. You know what you're getting and you know that the parts and assembly was all done right.

With a lesser quality AR such as Oly/DPMS/Bushy/RRA, you don't know what you're getting as far as parts or assembly, and time has shown that those brands are sub-standard. Even though there is a "standard" in the AR industry for DI guns, some companies just can't meet it.

With a piston AR, there's not even a standard (yet). There are nice piston rifles like the SCAR and HK416 which have had alot of R&D performed, and there is the Colt piston rifle which will probably have alot of the same parts/assembly attention to detail that their other rifles will have... but as for everything else... your guess is as good as mine. You don't know what you're buying. Having a piston doesn't necessarily make it a good thing. Just look at the Sig rifle, it's a piston AR and the only people who praise them are generally people who don't understand them or don't shoot them much.

Some of the questions that should be asked:
What is the piston made out of?
What are the dimensions on the piston?
The piston body?
What are the manufacturing tolerances for it?
What is the weight of the piston assembly?
How much should it weigh?
How fast does it travel?
How fast should it be traveling?
What is the bolt made out of? (since piston bolts are going to be different)
Etc, etc. Those questions are just the tip of the iceberg, not to mention what the rest of the rifle is like in parts/assembly quality.

There is no perfect way to measure and compare one piston rifle to another piston rifle since piston's aren't standardized, let alone making an easy comparison between a piston gun and a DI AR. You can however guess that based on the parts used and assembly of the rest of the rifle, that the piston assembly will either be close to or at that level of quality. Like how I inferred that a Colt piston rifle will probably be a good one because they know how to make rifles and (I hope) they will take their time and do their homework on how to make a good/great piston gun. SCARs and HK416s seem to have rather good reputation for being piston guns because FN and HK have been around for a long time, and they know how to make rifles. They also use very high quality parts... But there are many companies that now make AR's and make piston AR's that don't have that kind of background.

All that being said, having a piston doesn't necessarily make a rifle and better or worse by itself, it's a package deal. There is the possibility that time will show that a piston can be an upgrade but it will have to be one hell of a good piston assembly built onto a hell of a good AR in order to make an impact. A well made DI AR will work great and if you want a 10.5" short barreled rifle, even suppressed, or even full auto - a piston gun is still not necessary. In fact there are several drawbacks to a piston rifle over that of a DI AR. Reduced accuracy potential, increased weight, all of the unknowns and increased cost.

--------------

In direct response to your question -

LMT makes good stuff but LWRC is something I'd stay away from because of what I've read here on M4C (I have no personal experience with LWRC). However, if you like Noveske and you have Noveske rifles in your safe already then add another one to the family! The switchblock is great for suppressed use and the 10.5" N4 is a wholly reliable upper with and without the M4-2000 mounted. In fact, the 10.5" N4 with M4-2000 is exactly what I bought a year ago and I've yet to have a single problem with it. As far as I'm concerned for a 10.5" SBR, it's the cat's meow.

[MistWolf]

There is no reason that you "have" to go piston, in fact, many consider it NOT to be superior to a DI AR anyway. A piston rifle keeping a receiver clean is a matter of convenience, not a matter of functional or design superiority in the weapon system.

Piston is good for NOTHING in the AR realm.

Not true. Without it's piston, an AR will not function
http://i115.photobucket.com/albums/n289/SgtSongDog/AR%20Carbine/DSC_0114.jpg

What the AR doesn't need is a piston rod

[Moltke]

Not true. Without it's piston, an AR will not function
http://i115.photobucket.com/albums/n289/SgtSongDog/AR%20Carbine/DSC_0114.jpg

What the AR doesn't need is a piston rod

Yeah yeah, you know what I meant. ;)

[jonconsiglio]

I've owned a couple piston ARs (have a couple SCARs as well). I still have one upper but it doesn't see any use. All of my ARs now that I actually use are DI.

My 10.5" LMT is the most reliable SBR I've ever owned. It shoots extremely smooth, feels the same as my 14.5" rifles and works very well suppressed and with a variety of ammo.

I have an 8" PSD in 6.8 that works, but I've never shot it enough to really say. I would NOT buy it again though. I had a 12" MRP that worked also, but it did absolutely nothing better, or really even as well, as a DI 12.5".

The only 10.5" piston AR I've handled was a 416, but it wasn't mine and I only put a couple mags through it. It wasn't the lightest thing but it shot ok.

I haven't bought a piston AR in a number of years and the only reason I bought the MRP was a buddy had it and never fired it, so I took it cheap then sold it not long after.

I've noticed Larry Vickers has commented recently that a piston AR is a good choice for full auto and SBRs. He knows more than I do, but I haven't found any reason to buy a piston 10.5" over a DI 10.5" for me. I run mine hard and suppressed quite often and it hasn't had a single failure in more than a few thousand rounds.

[MistWolf]

Yeah yeah, you know what I meant. ;)

True, but at the same time, it's confusing. People think they need to add a "piston upper" to a AR because it's superior to a "direct impingement system". But in fact, the AR is NOT a direct impingement system and it already has a piston. It's kind of like telling someone their car would work better if they put an engine in it

[Cameron]

I have an LMT Direct Impingement AR with a 10.5" barrel that has functioned flawlessly for thousands of rounds. There is absolutely no need to add a piston to an AR, as they run very well when correctly made.

http://farm8.staticflickr.com/7164/6467920755_0d98b1937f_b.jpg

[TehLlama]

Since you mentioned dedicated suppressed for the upper, I'd read about Grant's Ultimate Suppressed SBR journey - with a smaller gas port the DI gun can actually have the benefits advertised by the piston guns, but be lighter, simpler, and smoother.

[sinlessorrow]

if your doing a dedicated suppressed SBR get a Noveske switchblock.

[RyanB]

if your doing a dedicated suppressed SBR get a Noveske switchblock.

Why bother? Just get a small port and be done with it.

I now have about 500 through my small ported 11" rifle. It's one of the nicest shooting rifles I own.

[restfortheweary]

I have thousands of rounds over the past 3 years, through my Noveske 10.5" (non-switchblock) and M4-2000 combo. I have had no issues with the setup. The bottom line is buy a quality upper, from a quality manufacturer and you will be good to go. By the way, the switchblock is nice.

[Magic_Salad0892]

If you're running a DEDICATED (or semi-dedicated) suppressed SBR.

Get a Colt or BCM M4A1 SOCOM profile barrel (16.1'') and have it cut down, and concentrically re-threaded (and target crowned) by ADCO.

Do not have them open the port. Specifically state that you don't want the port opened. Just to make sure.

They'll do the job right, and you'll end up with a 10.5'' gun with a .062'' port, which I find optimal for function unsuppressed (which will not lock back on the last round in a standard carbine receiver extension but will cycle. In an A5 it should lock back.) but for primarily suppressed use. For referance, I use(d) a .056'' port on a cut down SR-15.

However, most good manufacterers barrels should be good for SBR use.

But if you're never going to shoot it unsuppressed, then having the larger port may be unnecessary.

[Vash1023]

LMT MPR, buy both a DI barrel and Piston kit

[CarlosDJackal]

I started off with DI SBRs. The first was a 10.5" LMT Mk18 and followed that with a BCM 11.5".

I replaced those with piston uppers (all LWRCs), sold the DI uppers, and have not looked back.

The only reason I stopped using the DI uppers is because I am too lazy to clean y guns with any regularity. So after I started shooting the Mk18 with a suppressor, I had a failure to fire. Turns out I had so much carbon build up on the firing pin that it was not making enough of a dent of the primer.

I have not had any such issue since I bought my first piston upper (10.5" LWRCI M6A1) more than 14,000-rounds ago. I now have 3 SBRs (10.5", 12.7" and 8.5" PSD). YMMV.

[rob_s]

friends don't let friends buy piston ARs.

IMO if you're going to run the gun unsuppressed with any regularity, the Switchblock is worth having. If you're going to keep it suppressed 90%+ of the time, just cut down a 16" barrel to get the smaller gas port.

[rundm]

I have the LMT MRP CQB's in 10.5DI, 12.5 piston and 16in DI. I use the 10.5 suppressed with a thunderbeast 30 ba and unsuppressed and have fired wolf, brown bear and my reloads through it without problems or adjustments of any kind. It shoots very soft. So much so that I havn't even worried about setting up my piston to use the suppressor yet. I like the 12.5 piston very much but with the way the 10.5 shoots, I don't know that I will set it up for suppressed fire.

[justlikeanyoneelse]

All great points and ideas, little bias against pistons though :blink:

My two cents, if your state side and shoot for fun DI is the way to go. If your in a hostile less-than-urbanized area then pistons are your way to go. I've used the M16 and M4, its lighter and dependable when its properly maintained. Now I personally use a HK416 10.4 and it is heavier in weight and recoil but its a lot easier maintenance and looks f*#@# awesome.

Besides the whole DI vs piston argument is a "Dead end Argument," go with whatever you feel best with. For that guy or guys who want to argue with what I said, lets first argue about which is better, the AK or M16? Or how about Pro-life or Pro-choice?

[sinlessorrow]

All great points and ideas, little bias against pistons though :blink:

My two cents, if your state side and shoot for fun DI is the way to go. If your in a hostile less-than-urbanized area then pistons are your way to go. I've used the M16 and M4, its lighter and dependable when its properly maintained. Now I personally use a HK416 10.4 and it is heavier in weight and recoil but its a lot easier maintenance and looks f*#@# awesome.

Besides the whole DI vs piston argument is a "Dead end Argument," go with whatever you feel best with. For that guy or guys who want to argue with what I said, lets first argue about which is better, the AK or M16? Or how about Pro-life or Pro-choice?

I'll take an M16 over an AK every day of the week and then on the weekend.

I cant say I have ever been in the military but I have played with my MK18 clone in the desert where it ended up with a ton of sand in it by the end of the day and never had an issue. I made sure to keep it lubed though.

[justlikeanyoneelse]

Same here, M16 anyday.

The MK18 is the whole reason I bought a 10.4, there's something about an sbr that just makes you feel great.

[sinlessorrow]

Same here, M16 anyday.

The MK18 is the whole reason I bought a 10.4, there's something about an sbr that just makes you feel great.

I gotta agree with that, it doesnt get much better than a 10.3" rifle

[Toxicodendron]

I run a 10.5 Noveske w/ a SwitchBlock and it runs great suppressed. I would recommend the SwitchBlock wholeheartedly. It also lets me turn the gun into a single shot for when I am running sub sonic, for that extra bit of quite.

[RCO'B]

Go with the Switchblock, you won't regret it.