Wolf A1 complete upper $559 shipped

[Shotgun Surgery]

Necrosis

So you are making the bcg a piston? That's a huge stretch of the imagination. I am not really sure how to respond to such a crazy notion.

Why do you think the bolt of an AR15 has a gas seal on it? The gasses are redirected through the gas key and into the BCG. These gasses then create an expansion chamber which applies forward pressure on the bolt itself; the bolt and carrier together act as a piston. As the bolt is pressed up against the barrel extension, the forward pressure applied on the bolt instead launches the carrier rearward. Were there no gas seal on the bolt itself then the rifle wouldn't cycle; the gasses do not directly impinge the carrier and instead indirectly impinge the carrier by using the bolt and carrier together as a piston. Read the patent which was filed for the AR15.

 

[bulletpaluza]

Why do you think the bolt of an AR15 has a gas seal on it? The gasses are redirected through the gas key and into the BCG. These gasses then create an expansion chamber which applies forward pressure on the bolt itself; the bolt and carrier together act as a piston. As the bolt is pressed up against the barrel extension, the forward pressure applied on the bolt instead launches the carrier rearward. Were there no gas seal on the bolt itself then the rifle wouldn't cycle; the gasses do not directly impinge the carrier and instead indirectly impinge the carrier by using the bolt and carrier together as a piston. Read the patent which was filed for the AR15.

I understand how the AR15 works. It is not a piston gun. You can call the bolt a piston if you like. But An AR is not a piston gun just because it has one. It's not the most pure DI design but it's certainly is not a piston gun.

 

[Necrosis]

Necrosis

So you are making the bcg a piston? That's a huge stretch of the imagination. I am not really sure how to respond to such a crazy notion.

Haha, I'm no firearms physics expert, but I've listened to a few talk. They say the standard AR15 design is not truly DI by strict definition (as most of us would consider it to be) and it's not fully a piston design (even though the BCG works as one), but instead somewhere in between. I'll try to find the video from Forgotten Weapons that breaks this down.

Here it is:

 

[bulletpaluza]

Haha, I'm no firearms physics expert, but I've listened to a few talk. They say the standard AR15 design is not truly DI by strict definition (as most of us would consider it to be) and it's not fully a piston design (even though the BCG works as one), but instead somewhere in between. I'll try to find the video from Forgotten Weapons that breaks this down.

Here it is:

It's funny how we were just talking about this the other day

 

[User170512]

I understand how the AR15 works. It is not a piston gun. You can call the bolt a piston if you like. But An AR is not a piston gun just because it has one. It's not the most pure DI design but it's certainly is not a piston gun.

What makes a piston gun?

 

[Mrs_Esterhouse]

What makes a piston gun?

Highly skilled, male, engineers.

 

[joel2000]

What makes a piston gun?

LWRC

 

[Mrs_Esterhouse]

 

[Shotgun Surgery]

I understand how the AR15 works. It is not a piston gun. You can call the bolt a piston if you like. But An AR is not a piston gun just because it has one. It's not the most pure DI design but it's certainly is not a piston gun.

The bolt and carrier work together as a piston; this isn't a matter of opinion. The gasses do not directly impinge the carrier, as without the bolt acting as a piston the carrier wouldn't cycle. The redirected gasses indirectly impinge the carrier via a gas-powered piston. Just because it's different from a traditional external-piston design doesn't change the fact that the carrier cycles via a gas powered piston.

Again, the genius of Stoner was that instead of having a bolt, carrier, and piston he made the bolt and carrier together act as the piston. Less mass reciprocating and that mass reciprocates perfectly in line with the bore.

 

[Shotgun Surgery]

Haha, I'm no firearms physics expert, but I've listened to a few talk. They say the standard AR15 design is not truly DI by strict definition (as most of us would consider it to be) and it's not fully a piston design (even though the BCG works as one), but instead somewhere in between. I'll try to find the video from Forgotten Weapons that breaks this down.

Here it is:

The redirected gasses don't directly impinge the carrier, so it's hard to say it's a DI gun. Also, the gun cycles via a gas powered piston so it's hard to argue it's not a gas piston gun.

I'm not sure if you're familiar with the Youtube channel SmallArmsSolutions, but this guy is one of the most knowledgeable people on the planet when it comes to the AR15 design. He has actually written books on the topic and his videos concerning the rifle are well worth the time to watch. Anyways, in one of his videos he mentioned how the AR15 is not direct impingement and went through the explanation as to why, but as he has many long videos on the topic I've never been able to re-find where specifically he mentions this. Here is a link to his channel if you're interested - https://www.youtube.com/channel/UCn_AGhwovzeWrnqHFJpYWaw