Gas tube shortinig

[sgms18]

Anyone have tips for shortining a gas tube? I guess my main question would be, is the swell at the end of the tube where it goes in the gas key a must for the weapon to cycle? If so how would one recreate it? I just got 1 of spooks 7in barrels and the gas port looks to be about 1.5in shorter than pistol.

[mak91]

What I have done was put it in my drill press and while running hold a flat file against it and file it down a bit. I used a small nail in the free end and a clamp to support that end. Poor mans lathe :smile:

[Alleycat]

Cut the other side.

[sgms18]

Cut the other side.

then what do i do about the plug in the end?

[mak91]

You could IM tp555 here on the forum. He can make you a custom gas block that uses set screws to hole the gas tube in the block. With his you just cut off the plugged end.

[Alleycat]

then what do i do about the plug in the end?

Put it in the gas block. Mark for your roll pin. Drill the hole for the rollpin. Assemble. None of my tubes have a plug in them, but my guns are not what you would call normal run of the mill ARs.

[sgms18]

Put it in the gas block. Mark for your roll pin. Drill the hole for the rollpin. Assemble. None of my tubes have a plug in them, but my guns are not what you would call normal run of the mill ARs.

are your gas blocks open on the end? the hole that the tube goes in on mine goes straight through(open on both ends)

[Scalce]

are your gas blocks open on the end? the hole that the tube goes in on mine goes straight through(open on both ends)

It would be kind of hard to remove a roll pin if you only had a hole on one side.

[robrob]

He's talking about the gas tube hole--it goes all the way through the gas block so he needs a closed end gas tube.

[Alleycat]

are your gas blocks open on the end? the hole that the tube goes in on mine goes straight through(open on both ends)


No, none of them do.

[robrob]

To answer the original question, I don't know of any tool available to replicate the "bulge" on the end of the gas tube. I too assume the bulge is necessary to help seal the tube to the bolt key. You can get a custom sized gas tube made or simply replace your gas block with one that doesn't have a double open end gas tube hole.

[Alleycat]

You can get a custom sized gas tube made or simply replace your gas block with one that doesn't have a double open end gas tube hole.

This is probably best. You could try a brake line flaring tool. Gas blocks aren't all that expensive. I may even have one here I could send you.

[sgms18]

This is probably best. You could try a brake line flaring tool. Gas blocks aren't all that expensive. I may even have one here I could send you.

If you got a low pro closed end bolck that will fit under a Midwest Ind FF tube that would great. .750 ID

[mak91]

There really is no flair at the end of the gas tube. Take a good look and mic one up. I have two sitting here in front of me, I think they are from dpms. The tube diameter is .180 the tip that looks like it has a flair is .180 also. What makes it look like a flair is that two inch long section that is only .168. that starts about 3/16 from the end. My guess is that its there to reduce drag on the bolt carrier key as it moves. What I did on my 7 inch barrel with the short gas tube was cut down a rifle length gas tube to the length I needed ( I added a 1/8 inch allowing for the tube to shrink from the bends I needed to put in it). I cut this from the gas block side, this gave me a nice straight tube to start with. I put it in my drill press, supported the free end with a nail and a clamp for support and I ran a file on the tube giving me that 2 inch .168 section on the chamber side about 1/8 inch from the end. I then bent the tube by holding it in a vice and gently tapping it with a hammer. The hardest thing was bending it to the angles I needed. Here is my barrel with the gas tube I made, the gas block is open on both ends. Its not that hard you can do it :smile:

[Alleycat]

If you got a low pro closed end bolck that will fit under a Midwest Ind FF tube that would great. .750 ID

Well it meets all your criteria except its .937 ID. Sorry man.

[sgms18]

Well it meets all your criteria except its .937 ID. Sorry man.

Its all good, thanks for looking!

[JFettig]

The best way to do it is take a rifle gas tube, calculate the length you need(straight is approximately .025-.050" longer than it will be bent), chop it, turn it in a lathe, or you could try the file method I guess then bend it in a vice. I made myself a jig to bend perfect tubes every time. I've got to get back into building barrels and these tubes. hopefully soon I'll have time to do more.

Its not a flare, its just a cut behind the large diameter to keep it from sticking in the carrier key

Jon

[dick]

You could thread and plug the gas tube at the muzzle end, if you were to cut it there. Accuracy Speaks did this with a little other fine tunning to vent over gassed M-4's. Good luck!

[sgms18]

thanks for all the input guys! i ended up welding up 1 end of the gas tube hole so i now have a closed end gas bolck. now its just a matter of a little cutting, drilling and bending.

[Mike Bell]

pictures.....we need pictures.....I heard that barrel is pretty:nanabang: