WK180 rifle-length gas system conversions?

[421SuperDuty]

One of the biggest derps of the WK180 design is the mismatched gas system length for the barrel, so conversion to a rifle-length system (and proprely designed Tokarev/AR180-style gas piston, put those two together and you basically have a Sterling R18) goes a long way to make the gun better. I know TNA was offering the kit 2-3 years ago but now it's gone. Anyone have experiences with the kit, and is anybody offering anything similar, or has TNA said anything about selling it again or implementing that in the Gen 3?

 

[TrendyRendy]

I emailed them a month back about if they had any on hand tucked away or plans to bring some back.
They replied "we might in the new year have to make a new gas system"
So whatever that means

 

[the radium king]

i built a grendel on a mid-length system and it was more than adequate. rifle length not required i don't think. third echelon sell a mid-length system. tna sell a buffer to smooth things out. but then you have to find a mid-length barrel.

also, where the gas comes from (carbine, mid, rifle) is part of it but i think the bigger part is just the size of the gas port in the barrel. size the port right and it will run fine. i think the wk's came with big ports (overgassed) so that they would run anything. reduce the gas and the guns get picky on ammo. and a longer piston just means more weight forward on a gun that is already barrel-heavy.

a properly designed adjustable gas block is the ticket - ie, one that allows you to adjust gas AND remove the piston through the block so that you don't need a spring and can pin the block in place. but probably too bulky to fit under a standard AR15 handguard which was one of the original design parameters. which is not such a big deal these days as AR parts are getting tougher to find so a taller, proprietary handgard would work. but then everyone would complain it was too heavy or didn't look cool or whatever.

 

[421SuperDuty]

I emailed them a month back about if they had any on hand tucked away or plans to bring some back.
They replied "we might in the new year have to make a new gas system"
So whatever that means

Well that's some good news, they must realize the obvious problem.

i built a grendel on a mid-length system and it was more than adequate. rifle length not required i don't think. third echelon sell a mid-length system. tna sell a buffer to smooth things out. but then you have to find a mid-length barrel.

also, where the gas comes from (carbine, mid, rifle) is part of it but i think the bigger part is just the size of the gas port in the barrel. size the port right and it will run fine. i think the wk's came with big ports (overgassed) so that they would run anything. reduce the gas and the guns get picky on ammo. and a longer piston just means more weight forward on a gun that is already barrel-heavy.

a properly designed adjustable gas block is the ticket - ie, one that allows you to adjust gas AND remove the piston through the block so that you don't need a spring and can pin the block in place. but probably too bulky to fit under a standard AR15 handguard which was one of the original design parameters. which is not such a big deal these days as AR parts are getting tougher to find so a taller, proprietary handgard would work. but then everyone would complain it was too heavy or didn't look cool or whatever.

The gas port isn't the only problem, because with a short gas system and long barrel that gas from the smaller port will still be at a higher pressure for longer with a higher peak pressure than with a proper length gas system. It's complicated but there are good reasons why rifles and carbines have different positions for the gas port. An adjustable gas block isn't the solution, just a band-aid. Just because something works in the short term doesn't mean it's desirable or optimal.

And for the handguard, it's absolutely silly to compromise the heart of a self-loading rifle, the gas operating system, to fit a simple accessory. The Sterling uses an AR-10 handguard that are just as cool and almost just as common and allows for more room, the Templar has it's own thing (but still the silly, chonky single-piece piston?!). At this point, people just want a semi-auto with some MLOK that will last at least 10,000 rounds, and they want it fast.

 

[the radium king]

i understand the concept of dwell time when applied to a piston system, but realise that the high pressure isn't the issue otherwise no carbine-length (or pistol length!) system would work - the bullet doesn't know how much barrel is ahead of it so pressure is pressure - controlled by port size. ditto the fact that the action cycles a bit sooner because the gas is coming a bit sooner; still seems to work, mebbe just a different recoil impulse.

and sure the pressure acts for longer with a carbine port on a long barrel, but once the piston has moved all the excess pressure gets vented so dirty hand is all.

i think there are many benefits to a longer system, but mid-length is a good compromise from my experience.

 

[DaveGP]

If the AR180 original gas system design was copied, there would be no problems.

 

[Blastattack]

If the AR180 original gas system design was copied, there would be no problems.

I think the reason it wasn’t because it probably would not fit under a free float rail. They decided to keep AR15 rail height, probably due to ease of finding a supplier for extrusions, and maintain some compatibility with other aftermarket forends. The gas system sits higher for some unknown reason, and there is very limited space inside the rail for any moving parts.