From DI to Piston

[Rich LPS]

I was going to set my watch and see how long it took for someone to come on and advise me that pistons are older than the DI system and are a step backwards. Thanks for the hot tip.

The question at hand has been battered around this forum for years. People always running to the defence of the DI system.

When I speak of the piston being the way of the future, I mean take a look at the major players picking and using newer systems. The HK 416 is dominant right now. For those who can have whatever they want to fight with, they are picking the HK416 in droves. The "jobbers" who are producing retro-fit kits for standard AR's don't fit into this category, neither do the small companies who have never landed a significant Military / Police customer. Not all AR Piston systems are good or better than DI's.

The amazing round counts that have be achieved with HK G36 and HK 416's in endurance testing (often in a sandy environments) are nothing short of incredible. Also done with no lubing or cleaning of the system.

By the way, I love DI guns, especially the really good ones like Colt Canada and Knight's. I just don't think they are better than the really good piston guns, like HK.

Rich

 

[blaxsun]

When I speak of the piston being the way of the future, I mean take a look at the major players picking and using newer systems. The HK 416 is dominant right now. For those who can have whatever they want to fight with, they are picking the HK416 in droves. The "jobbers" who are producing retro-fit kits for standard AR's don't fit into this category, neither do the small companies who have never landed a significant Military / Police customer. Not all AR Piston systems are good or better than DI's.

The amazing round counts that have be achieved with HK G36 and HK 416's in endurance testing (often in a sandy environments) are nothing short of incredible. Also done with no lubing or cleaning of the system.

By the way, I love DI guns, especially the really good ones like Colt Canada and Knight's. I just don't think they are better than the really good piston guns, like HK.

Well said!

 

[Starscream]

I was going to set my watch and see how long it took for someone to come on and advise me that pistons are older than the DI system and are a step backwards. Thanks for the hot tip.

The question at hand has been battered around this forum for years. People always running to the defence of the DI system.

When I speak of the piston being the way of the future, I mean take a look at the major players picking and using newer systems. The HK 416 is dominant right now. For those who can have whatever they want to fight with, they are picking the HK416 in droves. The "jobbers" who are producing retro-fit kits for standard AR's don't fit into this category, neither do the small companies who have never landed a significant Military / Police customer. Not all AR Piston systems are good or better than DI's.

The amazing round counts that have be achieved with HK G36 and HK 416's in endurance testing (often in a sandy environments) are nothing short of incredible. Also done with no lubing or cleaning of the system.

By the way, I love DI guns, especially the really good ones like Colt Canada and Knight's. I just don't think they are better than the really good piston guns, like HK.

Rich

**sighs** I'm not saying pistons are bad, I'm saying I'd rather a piston gun designed from the ground up as a piston gun then jamming a piston system into an AR15. Read up on the Colt 703. Colt had a production prototype for a short stroke ready to go in 1968, in fact it was pitched as the M16A2.

If you gave me a G36 and an HK416, I'd take the G36 over the 416, any day of the week, for any situation that demands a firearm.

 

[blaxsun]

**sighs** ... If you gave me a G36 and an HK416, I'd take the G36 over the 416, any day of the week, for any situation that demands a firearm.

Really? I'm definitely curious why...

 

[Starscream]

Really? I'm definitely curious why...

Same service life interval for parts and the rifle, modular magwell to allow stanag or normal g36 magazines, folding rifle stock which can be upgraded, I'm not a huge huge fan to hanging too much gear off the front of the rifle (but I am a civilian).

I'm not planning on firing 600+ rounds a inside of an hour (I'd be using a C8 or C9 if I did because chances I'd be in the army at that point), I can't legally use a suppressor. Only thing that may have an advantage is being able to use an AR15 upper on the 416. If we're talking to the MR223 then you can't even use a HK416 bolt in it. So may as well go full all out incompatible with the AR15 and not be tied down by the limitations of the system.

 

[blaxsun]

Only thing that may have an advantage is being able to use an AR15 upper on the 416. If we're talking to the MR223 then you can't even use a HK416 bolt in it. So may as well go full all out incompatible with the AR15 and not be tied down by the limitations of the system.

Don't you mean any AR lower? (the upper is the whole purpose of the HK416) So you can't use the HK416 bolt in an MR223... because the trigger group is SA?

 

[Starscream]

Don't you mean any AR lower? (the upper is the whole purpose of the HK416) So you can't use the HK416 bolt in an MR223... because the trigger group is SA?

Apologies for the mix up there, yes I meant HK upper to AR lower.

No, the MR223 has a modfication to the barrel extension. There's a tab there that protudes out in order to prevent a normal AR15 or an HK416 BCG from being used, only the MR223 BCG will work. This was done to comply with German export laws.

MR223 chamber with the barrel extension visible. If you look near the 'top' of the extension you'll notice the protrusion which mates into this:

You'll see the cutout in the MR223 bolt carrier. AR15 and HK416 bolt carriers lacks this cut therefore the bolt will not seat. Below is an image of an HK416 BCG

It's not a huge deal mind you, I've never heard of a BCG breaking but it is a little irritating to look at.

 

[blaxsun]

Apologies for the mix up there, yes I meant HK upper to AR lower.

No, the MR223 has a modfication to the barrel extension. There's a tab there that protudes out in order to prevent a normal AR15 or an HK416 BCG from being used, only the MR223 BCG will work. This was done to comply with German export laws.

It's not a huge deal mind you, I've never heard of a BCG breaking but it is a little irritating to look at.

Never noticed that, to be honest. That's really annoying. Definitely HK416...

 

[Denka]

So HK MR223 is gas operated and HK426 Piston and both cannot be swapped uppers to operate?
Also, I see that guys who provide info regarding Piston keep referring to HK416. Is there less pricey piston rifle that proven that as well reliable?

 

[blaxsun]

So HK MR223 is gas operated and HK426 Piston and both cannot be swapped uppers to operate?
Also, I see that guys who provide info regarding Piston keep referring to HK416. Is there less pricey piston rifle that proven that as well reliable?

No - both the HK MR223 and HK416 are piston. Only the MR223 (commercial) is "neutered" such that you can't swap uppers and bolts; the HK416 (military) is not. And no - in terms of reliability with piston ARs - nothing comes close to HK.

 

[KevinB]

FYI the Colt gun from 68 was a Long Stroke -- I have two here.
Neat gun, but not an upgrade.

 

[greentips]

I know I won't refuse a HK416 upper LOL, but on the other hand I won't fork out 6000 bucks for one either. I like guns, but I cannot afford that kind of spending. Saw the HK submission for the Army carbine solicitation with the skinny barrel - LIKE.

The complaint over MR223 is academic. People just pick fault over HK to justify buying something like (______ insert your favourite local brand of piston gun here). All the stuff that HK did to MR223 do not affect functionality and reliability. Yes, I would prefer to have a combat type barrel instead of a competition style heavy barrel -now just see it as extra training weight to subsititute the missing weight of the 25 rounds that is supposed to be attaching to the rifle.

 

[Denka]

No - both the HK MR223 and HK416 are piston. Only the MR223 (commercial) is "neutered" such that you can't swap uppers and bolts; the HK416 (military) is not. And no - in terms of reliability with piston ARs - nothing comes close to HK.

interesting as my understanding about mr223 was that it is gas operated -
Link
I guess I was wrong then.
Both items available for civilian?

 

[blaxsun]

The complaint over MR223 is academic. People just pick fault over HK to justify buying something like (______ insert your favourite local brand of piston gun here). All the stuff that HK did to MR223 do not affect functionality and reliability. Yes, I would prefer to have a combat type barrel instead of a competition style heavy barrel -now just see it as extra training weight to subsititute the missing weight of the 25 rounds that is supposed to be attaching to the rifle.

Agreed. At the end of the day it's not like you'd necessarily want to run anything but an HK bolt/lower on an MR223 anyway. I mean you could - but really, why would you? Compared to an HK416 upper the complete MR223 package is a bargain...

 

[blaxsun]

Both items available for civilian?

Yes, although the HK416 is fairly unobtanium - so your best bet is an MR223.

 

[WAREWOLF]

Disagree, the platform was never designed around a piston system. The piston conversion was a solution for a problem that never existed. I think there's a reason some of the best AR manufacturers in the world don't bother with piston. IMO straight up gas and less moving parts seems more reliable...

You are Correct IMO. my LMT AR is a DI gun and i have had no issues, james or slow downs with it.

going piston wont solve anything for AR's except the bolt carrier group might be a little cooler in temp thats all

 

[KevinB]

Biggest falsehood on piston guns is that they run cleaner. 99% of the fouling in a gas gun comes from the round uncorking from the chamber when pressure is still in it.
Add a can and this is even more prevalent.

Changing the cam path is the best way to affect this, and its not possible to do with any sucess in the M16FOW due to the design of the bolt and carrier.

Pistons and DI systems have their own pro's and con's - myself I don't see a need to for pistons unless it is a VSBR, or a submerged firing requirement (and I dont want to get into the logic of that).

Note a key Tier 1 Maritime entity recently discussed replacement of their current cough piston cough platform and they specific DI.

 

[dizzy]

Cleaning the Gas System in a Piston. Best way to do this is to spray it with Wipeout, let it sit a day then wipe it out with a patch. You need something that dissolves the carbon, and wipeout seems to get the job done with the least hassle.

Its never a bad idea to use wipeout on a new piston as it coats the surface of the metal just enough to keep the piston from fouling.

 

[KevinB]

Point to note above, one of the biggest issues with DI guns is most still use 1958 era coatings.
You could do the same to a DI bolt and carrier that where done with a more effective coating.

 

[Dsiwy]

Biggest falsehood on piston guns is that they run cleaner. 99% of the fouling in a gas gun comes from the round uncorking from the chamber when pressure is still in it.
Add a can and this is even more prevalent.

Changing the cam path is the best way to affect this, and its not possible to do with any sucess in the M16FOW due to the design of the bolt and carrier.

Pistons and DI systems have their own pro's and con's - myself I don't see a need to for pistons unless it is a VSBR, or a submerged firing requirement (and I dont want to get into the logic of that).

Note a key Tier 1 Maritime entity recently discussed replacement of their current cough piston cough platform and they specific DI.