AR Sponsor
Posted: 6/29/2010 5:00:32 PM EDT
|
I've just about had 'em all over the last several years: HK, ARES (twice), LWRC (thrice), POF, Osprey, PWS, Ruger.
Obviously one of the selling points of the piston is the ease and speed of maintenance. Most designs tend to have a vent system, whether it be vent holes below a gas block but above the barrel, or cup-over-spigot forward facing design. These designs blow crud all over the FSB/gas block (and possibly the front sight if over it on a rail), and the front section of a rail system. My rating is as follows: 1) HK. Blows gas forward and away from the FSB out of a little vent hole on the front of the FSB, angled at ~45 degrees. 2) Osprey. Vents under the handguards/rail system, but does so in a rather neat line. It's a spigot-over-cup design, the opposite of the Adams/LWRC/ARES. Instead of blowing it all over the FSB/gas block and all over the forward rail (if you have one) it vents in an easily cleaned "line": right above it on the HG/rail and right below it on the top of the barrel. 3) The others. Not a slam on any of them function-wise, just where they blow the carbon. |
|
The Ruger blows the carbon down at an angle between the gas block and barrel. I've found that the gas "jet" is kind of hidden down inside the handguard. This keeps hot gasses away from optics, sights, slings, etc. I've got a light mounted to the end of the rail at the 3:00 position and it doens't have any fouling on the lens, etc.
The area between the gas block and barrel is rather hard to clean but I've had some success with a Q-Tip or two dipped in solvent. |
|
One thing I note on the PWS is the gas vent is straight down onto the barrel. This creates a small mountain of crud on top of the barrel. It usually will blow itself off but I've had to use a small wooden dowel a couple of times to knock it off. There is also some blow-by that allows carbon fouling back into the action. It's not nearly anything like on a DI gun but it is there none the less.
Something else I note with the PWS that I haven't felt from the HK or the Ruger is the old "gas in the eye" kind of like shooting a DI rifle. Anybody else notice this from the PWS? |
|
Quoted:
One thing I note on the PWS is the gas vent is straight down onto the barrel. This creates a small mountain of crud on top of the barrel. It usually will blow itself off but I've had to use a small wooden dowel a couple of times to knoock it off. There is also some blow-by that allows carbon fouling back into the action. It's not nearly anything like on a DI gun but it is there none the less. Something else I note with the PWS that I haven't felt from the HK or the Ruger is the old "gas in the eye" kind of like shooting a DI rifle. Anybody else notice this from the PWS? I actually edited my OP, as there was one I forgot. It wasn't real easy to get the carbon off underneath the gas block (like PWS does), but it's doable. ETA––-I remember trying to stick a folded piece of tinfoil under the Ruger's gas block while range shooting. Then just pull it out and throw it away! The gases blew the tinfoil mostly apart after a few rounds. 
Thought here: what if someone designed a pop-in and pop-out piece of aluminum that you could "catch" carbon ejection on and easily pop-out and clean, then easily replace. The Ruger would need one, the PWS, any others? |
|
The gas vents on the Ruger are at an angle. This keeps the little mountains of carbon from forming like they do on the PWS.
Despite what many on the boards seem to think, Ruger put alot of time and thought into their system. They will no doubt continue to make customer-driven changes and evolutionary changes to the gun but I doubt their basic piston system will change anytime soon. I, too, was concerned about carbon build-up down in the Ruger initally. But it's really nothing other than cosemtic from what I've seen. It never seems to do anything other than look kind of dirty. In its location, it doesn't get on clothes or smudge off on fingers, etc. |
| With these guns that vent downward––-is there any reason they can't vent upward at angles (like away at a 45 degree angle to the sides) or forward of the gas block? The Ruger and the PWS have an internal piston like the HK does but vent elsewhere. Could HK actually have a patent on where or which direction the gases blow? |
|
It might be just different design ideas of what to do with all that gas.
On the SCAR, as an example, the gas vents out the left side of the gas block. I scorched my sling by mistakenly mounting it too close to the vent. The AUG vents out and down on the right of the gas block. I've gotten my fingers too close to the vent holes once or twice. It hurts but doesn't really cause any damage. But I can tell you that the gun throws a tremendous dust cloud when shot from broke back mountain position. |
|
Quoted:
Could HK actually have a patent on where or which direction the gases blow? Nope. HK is european company. In Europe you can not patent such thing, as you can not patent obvious, common sense or popular practice (actually only patent on 416 that HK holds is gas rings on piston - as it was originally patented for G36 and piston is same as in G36). Reason why HK has that is becouse HK pays attention to details and cares about such thing - part of insane price goes for that (like you have this included with BMW as well). On side note -> current 10.4" 416 is not venting gases from gas block, becouse muzzle is so close to block that it's not needed. Only longer barrels (14.5" and 16.5") vents. |
|
Quoted:
I own an LWRC and an Osprey converted piston system. I have found that my Osprey runs cleaner but my LWRC runs a bit cooler. Hoe this helps ya some. Having owned both, I concur. Just in the amount, location, and distribution of carbon/gas. Can't speak for the "cool" temps. |
AR Sponsor
Win a FREE Membership!
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.