Welding oversized gas port?

[ScottsBad]

This is a crazy thread. The only two possible answers are: 1. A new barrel and a new gas block. -OR- 2. Get and adjustable gas block. That's it.

1. Welding a barrel is crazy and could cause weakening or warping of the surrounding material. Kinda red neck shade tree gun smithing IMHO.
2. Putting a set screw in is even crazier.
3. Using the gas port reducer might be a solution, but it might cost as much as a new barrel.
4. If you do get a new barrel, you'll probably have to get a new sight/gas block, as it is very difficult to line up drilling for a taper pin through an existing taper pin hole.

5. An adjustable gas block is probably the cheapest way to solve it legitimately.

This is why I won't buy used weapons...

[sidewaysil80]

This is a crazy thread. The only two possible answers are: 1. A new barrel and a new gas block. -OR- 2. Get and adjustable gas block. That's it.

1. Welding a barrel is crazy and could cause weakening or warping of the surrounding material. Kinda red neck shade tree gun smithing IMHO.
2. Putting a set screw in is even crazier.
3. Using the gas port reducer might be a solution, but it might cost as much as a new barrel.
4. If you do get a new barrel, you'll probably have to get a new sight/gas block, as it is very difficult to line up drilling for a taper pin through an existing taper pin hole.

5. An adjustable gas block is probably the cheapest way to solve it legitimately.

This is why I won't buy used weapons...

How do you figure the gas port reducer might cost as much as a new barrel? I just ordered it for $35...

The gas port is still smaller than 90% of the 10.3-10.5 barrels on the market, it was just three thousandths more than I wanted. They offered a couple of solutions and I wanted to see if any other options were out there. Thread served me well as I learned of Clint’s inserts and will be using one of those.

If plugging the port, drilling and tapping for a set screw and then TiG welding would be the route that I'd go.

The inserts that are being discussed are on the gas block, not barrel. You drill/tap the gas block and insert reducer in there and then gas block slides on like normal. The insert can’t move or back out and it effectively gives you whatever port size you want.

[Tigwelder1971]

How do you figure the gas port reducer might cost as much as a new barrel? I just ordered it for $35...

The gas port is still smaller than 90% of the 10.3-10.5 barrels on the market, it was just three thousandths more than I wanted. They offered a couple of solutions and I wanted to see if any other options were out there. Thread served me well as I learned of Clint’s inserts and will be using one of those.



The inserts that are being discussed are on the gas block, not barrel. You drill/tap the gas block and insert reducer in there and then gas block slides on like normal. The insert can’t move or back out and it effectively gives you whatever port size you want.

I understand the inserts for the gas block.

On a side note, gas ports in bbls are successfully TiG welded and redone commonly.

[HeruMew]

This is a crazy thread. The only two possible answers are: 1. A new barrel and a new gas block. -OR- 2. Get and adjustable gas block. That's it.

1. Welding a barrel is crazy and could cause weakening or warping of the surrounding material. Kinda red neck shade tree gun smithing IMHO.
2. Putting a set screw in is even crazier.
3. Using the gas port reducer might be a solution, but it might cost as much as a new barrel.
4. If you do get a new barrel, you'll probably have to get a new sight/gas block, as it is very difficult to line up drilling for a taper pin through an existing taper pin hole.

5. An adjustable gas block is probably the cheapest way to solve it legitimately.

This is why I won't buy used weapons...

How does 35 equal 100+ for even a cheap barrel. 250+ for higher end.

I agree with the welding aspect, to an extent, but that's the only piece that made sense.

[MistWolf]

No I appreciate the insight, can you explain what you meant regarding the insert not mimicking the barrel port size? Before I read your response I ordered a .070" insert kit but I don't mind adding a smaller one to test first.

The gas flow in the barrel is supersonic. When a supersonic gas passes through a restriction, it is slowed to just less than the speed of sound. The rules for supersonic gasses flown through a restriction are different than subsonic gasses flowing thorough a restriction, affecting flow rate.

Therefore, the gas flow through the barrel port will be affected differently than the flow through the Micro Port.