Why not more DI guns?

[TED]

I actually really like the DI system and appreciate its benefits.

So, why don't we see more guns using it?

In particular I would love to see a DI bullpup.

TED

[georgeib]

My best guess is that the buffer tube/receiver extension part of the system that DI seems to necessitate is not nearly as popular as the DI part of it. There are more compact ways to make the rifle cycle in other words.

[Magic_Salad0892]

My best guess is that the buffer tube/receiver extension part of the system that DI seems to necessitate is not nearly as popular as the DI part of it. There are more compact ways to make the rifle cycle in other words.

Daewoo K1.

All the fixed ejector guns I’m familiar with need to have a slot cut into the bolt body and bolt carrier, preventing them from being used as a Stoner type gas cylinder and piston.

Gas port size is critical for pretty much any gas operated gun. I think the reason you hear about it so much with ARs is because of the popularity of home built guns and the possible combinations of barrel length, gas port locations, and gas port sizes.

H

Daewoo K1.

[noonesshowmonkey]

My best guess is that the buffer tube/receiver extension part of the system that DI seems to necessitate is not nearly as popular as the DI part of it. There are more compact ways to make the rifle cycle in other words.

Pretty much this.

I love how this thread included several pages of diatribe between a dude named after a Warsaw Pact round, who is obviously a fanboi of AKs, shitposting on a forum named after the M4. That love letter to the AKM was hilarious. Also, the trotting out of the supposed failures of the AR pattern was equally absurd. You can dump Mobil 1 on a BCG and it'll cycle. If you want to play games shoveling sand into the massively open action of an AK and wow everyone that it'll cycle, then cool. Youtube is your friend. Meanwhile, in reality-landia, plenty of savages are getting tamed every day by DI guns. Piston, too. But to call out a system that is blatantly effective, bordering on genius, as worthless compared to the WW2 era AK is both absurd and smacks of ego.

Is the way forward with rifle designs to have a piston? I think so. I think that solving the problem of cycling the weapon at the gas block is not a bad idea, and the SG55x series are a kind of holy grail. I'd love to get my hands on one, but I am a reasonable man, and won't spend $4000 on a rifle, and I wasn't born Swiss, so I won't get issued one. Even so, I think that the chief advantages of the SG 55x series comes with them being suppressor compatible with a switchable gas block, and with a folding stock. Those are pretty much the main features that I'd be looking for in a next-gen rifle. And, interestingly enough, it looks like the .mil world agrees with me, or rather, I with them. Thus, the MCX.

[bruin]

Easy - any new DI gun will be immediately compared to the AR, which is proven, likely much cheaper, and enjoys the broadest aftermarket support in gun history.

Plus the popular view is that pistons are more sexy than DI. There isn't any money in a new DI design.

[halmbarte]

DI does eliminate the need for an op rod and moves the gas system back to the BCG. It’s not compatible with corrosive ammo (try to get the gas block and inside of the tube clean) for field use and does require a BCG that can be pressurized, eliminating using a fixed ejector, for example.

DI also wouldn’t work with weapons that need quick barrel changes as you’d have another point for gas to leak out of.

As far as a DI bullpup goes, the Tavor is about halfway there. Gas is ported back 3~4” from the barrel tap to the long stroke piston head. From there back it’s pretty much AK like, with improvements.

H

[vicious_cb]

DI does eliminate the need for an op rod and moves the gas system back to the BCG. It’s not compatible with corrosive ammo (try to get the gas block and inside of the tube clean) for field use and does require a BCG that can be pressurized, eliminating using a fixed ejector, for example.

DI also wouldn’t work with weapons that need quick barrel changes as you’d have another point for gas to leak out of.

As far as a DI bullpup goes, the Tavor is about halfway there. Gas is ported back 3~4” from the barrel tap to the long stroke piston head. From there back it’s pretty much AK like, with improvements.

H

DI is absolutely compatible with corrosive ammo. Many of here have shot out 5.45 uppers with corrosive ammo with no cleaning of the gas tube or FSB.

DI quick change barrel uppers exist and work just fine. Look up the Dolos AR-15, there just no need for it.

DI bullpups? Im sure theres a conversion kit out there somewhere but theres not really a growing market for bullpups.

[Aries144]

Why would DI prevent the use of a fixed ejector?

[amd5007]

Not sure of the history, but Stoner moved away from it. Aside from that I can only think of 2 or 3 other DI gas designs. I think the piston system is a generally more forgiving system and easier to work around. For example, discussion of gas port sizes are almost unheard of in discussions of piston operated systems. In a DI gun, gas port size is vital.

[SteyrAUG]

Not sure of the history, but Stoner moved away from it. Aside from that I can only think of 2 or 3 other DI gas designs. I think the piston system is a generally more forgiving system and easier to work around. For example, discussion of gas port sizes are almost unheard of in discussions of piston operated systems. In a DI gun, gas port size is vital.

Unless it's a US SIG rifle.