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View Full Version : My Very First Gas Piston Build and Range Visit


xounlistedxox
02-01-2010, 3:54 PM
I've wanted to check out a gas piston setup for awhile now, but they have always been way overpriced. Fortunately they are coming down in price and there are some really affordable conversion kits out there. I picked up a Gas Piston Retro Fit Kit for under $250. I pretty much used spare parts laying around for the most part for this build. I must say this was a very easy install. The kit fit perfectly and I didn't have to do much fitting except to my free float rails.

Range Report:
Well it was a little strange at first since I have only owned DI rifles for the past couple of years, but here are some of the differences I noticed...

-Different Sound, I am not sure how exactly to explain it, but with the piston the rifle just sounded different and a little louder than DI

-Faster lock time, The very first round I spent seemed very odd. I saw the hole in the target, but it didn't feel/sound like the bolt had returned to battery, so I looked and sure enough it was. With a DI you can sort of feel/hear the bolt do it's thing, but with the piston it's so much faster that you don't notice.

-Accuracy about the same @25 yards, I was shooting at 1" orange dots @25 yards with Magpul MBUS's and most shots after I got my rifle zeroed were touching

-Recoil felt different, Another one that's somewhat hard to explain, but I would say it's something like this... with my DI's it seems like I get a little recoil and also some muzzle rise, but with the piston it seemed more like the recoil was just straight back with little to no muzzle rise.

-Cleaning, Here's what I would consider the biggest difference. I shot about 150 rounds total... granted that's not a lot, but quite a few were South African Ammo which is pretty dirty ammo. A range session with my DI's and this much would be enough to get it plenty dirty and warrant a decent cleaning. The piston was far different. The bolt carrier group had very little build up on it at all and did not need cleaning. The inside of the upper only had a tiny bit of build up around the feed ramps, on the chamber face, and a little inside the upper itself, but not where the bolt carrier group touches, so not a big deal. The op rod for the piston setup had very little build up and did not need to be cleaned. I would say the dirtiest part was on the gas block. I cleaned this by simply removing the op rod assembly and sliding a microfiber cloth down in between the rail and gas block with some g96 on it and wiping it a couple times then it was done.

-Function, this was the same as all my DI rifles flawless.

-Bolt Carrier Group, Cold. I touched the front gas block and burned my hand, so I figured that would be a good opportunity to check out the BCG like they advertise and sure enough it was as cold as it would have been if I had just pulled it out of my safe without firing it.

-Gas Adjustments, My kit has 3 settings. Standard, Suppressed, and Off. Obviously since I'm in CA I don't have a silencer, so this setting isn't of much use for me. I really like the off setting though because when I put in my .22lr conversion kit I can turn the gas system off so that it doesn't get fouled up by the very dirty bulk pack ammos of .22lr.

I have had zero problems with my DI guns, but I figured I would check out the piston route anyway. I would say either way is a good way to go. The piston would be a lot easier to maintain for extended periods of time, but there are several different designs and not many common parts, so if one breaks you could be at a big disadvantage. With DI's I like many of you who build these rifles constantly have a ton of extra parts that are vital to the DI setup working, so if SHTF, or whatever I have enough parts to keep my DI rifles going for many years of service, but I have no extra parts for my piston. In addition if you want extra parts for the piston they cost an arm and a leg.

I'm sure this has all been covered more than once, but I like sharing my personal useful experiences with fellow calgunners.
http://i415.photobucket.com/albums/pp240/xounlistedxox/img1264900779060.jpg

cqbdude
02-01-2010, 4:12 PM
Thanks for your comments....

I'm sorta thinking of going the same route as you..
I just wanted to try one, since I have a few DI uppers already.
And I have an extra 16inch upper I would like to convert..
I appreciate the comments....
Got any pics?:D

xounlistedxox
02-01-2010, 4:13 PM
yeah I do have a pic I'll post it up in a minute

engineers101st
02-01-2010, 4:16 PM
Very informative thanks :)

Joerocker
02-01-2010, 7:05 PM
Killer rifle.............

osis32
02-01-2010, 7:18 PM
whered you get the piston kit so cheap? Id consider trying one for that price.

xounlistedxox
02-01-2010, 7:20 PM
I bought it from a friend. The best price I've seen from retailers is $299 for the same kit from Area 51 Tactical
http://store.a51tactical.com/index.php?main_page=product_info&products_id=1713

xounlistedxox
02-13-2010, 1:15 PM
I just picked up a One Piece Bolt Carrier. I must say that this is a very high quality carrier. You can tell a lot of effort went into it's design and machine process. All edges are smoothed, the coating is uniform, and the design is altered from a standard carrier to work specifically with their piston system. Overall I am very pleased with it.

CHS
02-13-2010, 3:21 PM
-Gas Adjustments, My kit has 3 settings. Standard, Suppressed, and Off. Obviously since I'm in CA I don't have a silencer, so this setting isn't of much use for me. I really like the off setting though because when I put in my .22lr conversion kit I can turn the gas system off so that it doesn't get fouled up by the very dirty bulk pack ammos of .22lr.


The gas block will get just as fouled up with the gas turned off as it would turned on with .22lr. The settings won't make any difference.

xounlistedxox
02-13-2010, 3:22 PM
It is better to have a gas block fouled up than the piston.

maxwellca21
02-13-2010, 3:26 PM
very interesting thread....pleasure reading.

Grendel Guy
02-13-2010, 3:37 PM
Informative thread. I'm curious, what length barrel and what handguard? I've an Adams kit as well for a 24" barrel. I like the way the Vtac looks, but from what I've seen, no tubular free float will with with Adams. MI makes a tubular that they say will work with some piston kits, but not Adams (an email from them says that it'll only work with CMMG kits, at least in rifle length).

CHS
02-13-2010, 3:57 PM
It is better to have a gas block fouled up than the piston.

*forehead smack*

What do you think is going to happen when you turn the gas back on and shoot some .223/5.56 after shooting .22lr?

xounlistedxox
02-13-2010, 5:23 PM
Well in a range environment you can carry qtips and wipe out the carbon in the gas block before putting the 5.56 setup back in and using it, so the fouling wouldn't move through the system. This setup doesn't get that dirty until you start getting really high round counts. I've shot an entire 550 round box of Federal bulk pack with the gas system off and it was less dirty than a 5.56 inside the upper receiver after 100 rounds.

tomd1584
02-13-2010, 5:28 PM
thanks for the report.

xounlistedxox
02-13-2010, 5:58 PM
Informative thread. I'm curious, what length barrel and what handguard? I've an Adams kit as well for a 24" barrel. I like the way the Vtac looks, but from what I've seen, no tubular free float will with with Adams. MI makes a tubular that they say will work with some piston kits, but not Adams (an email from them says that it'll only work with CMMG kits, at least in rifle length).

Tubular rails from what I have seen will not have enough room.

aplinker
02-13-2010, 6:09 PM
*forehead smack*

What do you think is going to happen when you turn the gas back on and shoot some .223/5.56 after shooting .22lr?

lol

Gotta keep that piston head free of all that 22lr fouling. :D

xounlistedxox
02-13-2010, 6:14 PM
The less cleaning I have to do when I return home the better. It's a short stroke design and has two tubes basically that contain/release the gas pressure and spread out. Even with several hundred rounds it doesn't get dirty enough to worry about, but if you can save it from getting dirty while shooting your conversion kit then why not?

CHS
02-13-2010, 10:20 PM
Clearly, someone has no idea how their rifle works.

xounlistedxox
02-13-2010, 10:52 PM
Clearly, someone has no idea how their rifle works.

What in the world are you talking about? I built this rifle piece by piece from a stripped upper and a stripped lower I'm very aware of how it works in all aspects.

CHS
02-14-2010, 7:20 AM
What in the world are you talking about? I built this rifle piece by piece from a stripped upper and a stripped lower I'm very aware of how it works in all aspects.

Then what on earth do you think you're accomplishing by turning off the gas port when you're shooting .22lr through it?

Off or not, the fouling is going to go into the exact same spot no matter what.

Even with the gas port turned off, if debris is not making it as far as the piston cup, it certainly WILL make it there as soon as you open up the gas again and clear the block out with some .223.

I've installed a few of the Adams Arms kits and know them pretty intimately. The part that gets dirty with the gas off is not something you're going to be able to get to with some Q-tips.

What you're saying makes no sense.

Acorn556
02-14-2010, 7:40 AM
What he DID makes no sense.

Youbought a piston upper, fired 1 MOA groups at 25 yards using iron sights and burned your hand because you wanted to know how hot the FSB was. It sounds like the only reason you bought the piston upper was because you don't like cleaning your gun. Simple solution. RUN IT WET. Or you could sell it and buy a gun that needs to be clean to run.

xounlistedxox
02-14-2010, 7:43 AM
Granted there will be fouling in the barrel, and the "up pipe" so to speak inside of the gas block. Fouling inside the barrel can be easily removed by a boresnake prior to putting your standard bcg back in the upper. If you ran the conversion kit with the gas system off and snake the barrel prior to putting your bcg back in then the only fouling left will be the tiny bit in the "up pipe" and the rest will have accumulated on the outside of the "piston" which is easier to clean than the inside albeit not a great deal. As previously stated this will make cleaning easier. If you don't believe me you're more than welcome to go to the range with me as I go to the standard range one weekend then to blm land the next for drills etc.

xounlistedxox
02-14-2010, 7:53 AM
I didn't buy a piston upper. I built a piston upper. I did this just to check it out. I have several DI rifles and black rifle disease has got me for the past several years, so it was time for a change. I have read a ton about piston uppers prior to building one, but I approached it with no pre-conceived notions and posted this thread with my first hand experience from taking my rifle to the range. I like the lesser maintenance required of a piston upper, but DI's in an AR platform are a lot more common and I have no problems cleaning my weapons, but if you can make any job easier then why not? I actually enjoy cleaning my firearms with the exception of carbon build up on the bolt tail... everything else I enjoy. If you don't care to know about, or appreciate my first hand experience/review then simply press the back button and read another thread that will tell you exactly what you want to hear.

What he DID makes no sense.

Youbought a piston upper, fired 1 MOA groups at 25 yards using iron sights and burned your hand because you wanted to know how hot the FSB was. It sounds like the only reason you bought the piston upper was because you don't like cleaning your gun. Simple solution. RUN IT WET. Or you could sell it and buy a gun that needs to be clean to run.

aplinker
02-14-2010, 8:01 AM
I'll say it bluntly.

Piston head and bolt tail fouling are both meaningless. They do not need to be cleaned.

xounlistedxox
02-14-2010, 8:10 AM
I'm well aware that it's not absolute necessity to clean every last bit of build up on the bolt tail off, but do I clean it off every couple of times to the range, so if that process can be easier without changing much of anything then I'll make that change. My time is valuable to me, so less time cleaning means I have more time to spend more $ feeding black rifle disease :)