AR still won't work

[243winxb]

From your other thread -

OP Said- the barrel I used (10.5 inch melonite AR-Stoner). The bcg was ordered from Palmetto State on sale (not sure precisely which model, but I'm sure the problem isn't with the bcg). Buffer tube is a Phase 5 Hex-2, and I used the buffer and spring that came with it. Gas block and gas tube are from some chinaland outlet. Has block is low profile with two hex screws holding it to the barrelUpdate: So, having checked everything else, to no avail, I decided to try opening up the gas port. I discovered that the port was 0.069, so I broke out my set of machining drill bits, left over from my brief stint trying to learn metal fabrication in college, selected size 0.073 and set to work. I guess the bits were older than I had thought and become brittle with disuse. So long story short, I have an unknown length of 0.073" drill bit broken off inside a 0.069 hole, and a broken heart. So new problem. Should I try blasting it out by shooting a round through (the barrel is unobstructed), or do I just need a new barrel?

You need some expert help with your pistol. http://www.ar15.com/forums/b/3_AR_15.html Ar Pistol Systems

I dont have a guess.

 

[JeffG]

your gas tube is plugged

+1

 

[243winxb]

KAK Industries 11" bbl with carbine gas is .084 - .086"
Mega Arms 10.5" bbl with carbine gas is .080"
Green Mountain 10.5" bbl carbine gas is .087"
Anderson 10.5" bbl carbine gas is .086"
Ballistic Advantage 11.5" bbl carbine gas is .073"
Ballistic Advantage 10.3" bbl carbine gas BA HANSON with low pro gas block pinned is not public (proprietary)
Aero Precision 10.5" bbl carbine gas .0785"
Faxon 10.5" Gov't/Socom bbl with carbine gas is .080"
Faxon 11.5" Big GUNNER bbl with mid-length gas is .110"

https://www.ar15.com/forums/t_3_118/703666_Gas_Port_Sizes_on_10_5_to_11_5_Barrels.html

Where the port is located in the length of the barrel is a big factor, also.

 

[cdb1]

I'd take the gun to a gunsmith.

 

[243winxb]

10.5 inch melonite AR-Stoner

https://www.midwayusa.com/product/1...contour-1-in-7-twist-105-chrome-moly-melonite

Some Reviews say, gas port to small.


Technical Information



Barrel Length: 10.5"
Gas Tube Length: Carbine
Gas Block Diameter: 0.750"
Twist Rate: 1 in 7"
M4 Feed Ramps: Yes
Muzzle Thread: 1/2"-28

Most Helpful Positive Review


What can you say it works! Good price!

Hey it works and for $100 you can't go wrong just put 100 rounds throuh mine and was as good with it at 50yrd as my 16 inch rifle. Note: the gas port hole on mine was .063 Dia and .300 fwd of the Gas block /front sight lip , before you install the gas block measure the distance from the edge as my Yankee Hill was .270, so if you install the Gas Block flush to the lip (as I first did) you may have cycling issues! not Enough gas! I moved the block fwd leaving a .030 gap! and now its working like a chmap. so for the money and my fist AR build I am happy.

 

[wally]

So long story short, I have an unknown length of 0.073" drill bit broken off inside a 0.069 hole, and a broken heart. So new problem. Should I try blasting it out by shooting a round through (the barrel is unobstructed), or do I just need a new barrel?

There is a point of diminishing returns, although you can still learn a lot by continuing to futz with it.

Its very hard to be sure the barrel is not partially obstructed by the broken bit -- it could protrude into the groove but not above the land and thus be very hard to see. If a dry patch on a tight fitting .223 jag runs through without snagging it might be OK to try shooting it out, but I'd still advise against it.

Did you try to drill it "by hand" with a pin vise using the drill as if it were a reamer as I'd suggested? My suggestion is to get a 1/16" punch and use it to break-up and drive through the broken bit and then try to finish the hole with a new bit doing it slowly by hand, invest in some cutting oil too. The drill material is hard and brittle and driving through a broken bit stuck in a through hole you were trying to enlarge isn't as hard has it sounds as long as you were only enlarging by one drill size.

Good Luck! Although a new barrel, gas tube, and gas block might be the best way to proceed and write it off as tuition for the school of hard knocks.

 

[carbine85]

I think you found your problem, you just created a new one. Sometimes a broken bit is easy to get out. If there isn't enough to grab try punching it thru.

 

[243winxb]

. I have carbine length tube installed

How does that work with a 10.5" barrel?

US Made stainless steel AR 15 Gas tubes.

Pistol 6-5/8"
Carbine 9-3/4"
Mid-Length 11-3/4"
Rifle 15-1/4


How about a Pigtail tube?
http://www.barrierdefense.com/AR15-Pigtail-Gas-Tube-for-AR-15-Pistol-Pigtail-Tube.htm
I will not be building one, any time soon.

 

[MistWolf]

I built a 10.5" carbine gas AR and it ran fine. Of course, at .082", the gas port is much too large, but an adjustable gas block solved that. The problem isn't from the barrel being 10.5". I don't think it was because the gas port is too small. I think it has to do with the Chinese made gas port

 

[maxxhavoc]

How does that work with a 10.5" barrel?

Like this:


Mine has a .093 gas port. Works great.

Link to barrel:
https://www.classicfirearms.com/arbarrel10-5m4stainlessm4bar1in7twistcm410517ss