JRoss

After a bit of a break from the forum I have got the gun operating the way it should. I finally got a gas tube @ 15 1/2" and an adjustable gas block installed. I had to trim 3/16" of an inch off the muzzle end of the floating hand guard to make it possible to remove the hand guard without removing the gas block. Turned out it had an Armalite barrel installed on the upper and the gas tube was not fully seating in the gas key. I don't know if I really needed the adjustable gas block but it has one on it now. Next will be mounting a small picatilly rail on the hand guard for a sling loop and bipod. Want to get a scope on it too. I want to thank everyone for their input

Yes I surely will

That's the measurement I have been finding also, so I called FA on the phone to verify length a guess what he said he was very very wrong and they do have one to send me at 15.5". I did ask him if he was absolutely sure it was 15.5" and he confirmed that he measured it himself and it was 15.5". He said it will ship Monday of next week. Extended length national match gas tube for use with barrels with extended gas systems. Length: 17.170" (I have 2 of these if anyone is interested)

They told me it is just about 12"or so and not the 15.5" that I am looking for. I thought the 12" was a carbine length tube

Great catch survivalshop! thanks. I sent FA an email for an actual length and waiting to hear back from them.

Waiting on an Armalite AR10 rifle length gas tube ;(

Crossroads Show yesterday and no luck still waiting on backorder gas tube.............

"out of stock" and "backorder" just have to wait

Here is my last email I sent to Blackthorne (the company I bought the POS from) last Thursday and still no response. My rifle is still not working correctly. You do not answer my Email. Are you still in business or did you go under and change your business name again? It would not be a surprise if you did go out of business because your name is not good when doing a search about your company. Do you know anything about a gas key? Or a gas tube? Or a gas block screw length? Or the weight of a buffer? Or how to clearance an upper for the gas tube at the point the tube goes through the barrel nut? Or the end of the bolt carrier group protruding back beyond the end of the upper at the point where the buffer contacts the bolt carrier group? Or the difference between an AR10 Gas tube length and an AR308 gas tube length? Maybe if you did know more about these thing and checked them when you assemble an AR308 you wouldn't have soo many bad comments about your business on the internet and web forums. Send me an AR10 gas tube free of charge because the one you put in my rifle is wrong as well as all the other things listed above. Do you know what length the gas tube is for an AR10? Do you really pay someone to assemble your rifles? I bet your company doesn't show up at gun shows using any of your present or past business names either. Companies like yours give internet sales bad names.

I was going to but I spent it on a double whiskey over the rocks...........about the price of a gas tube

Cheap entertainment at its best! For another $5 bucks a could get a beer and then the fun would really begin! Maybe Blackthorne would just buy me the AR10 gas tube and write it off on their taxes under a warranty claim. I know they would have a lot of attention at their booth if I was there cheering for them.

I hope Blackthorne does, I could vent on them but probably would have to stand in a line out the door to get close enough for them to hear me!. One of my favorite songs too!

HaHaHA OK I will ask and see if its in their book. Do you want in if they got it listed?

Damn good odds I will take that bet for a ten spot

Got my new buffer and spring in the mail. Was making a trip into town so I called ahead to a shop in and asked if they had a AR10 gas tube and if it measured 15 1/2", the guy said yes so I asked if he could hold it for me and would be there in an hour. I get there and tell him I called about the tube so he hands me the tube and I get my tape measure out and guess what............. it measures 15 3/16". I wanted to say something smart a$$ but didn't knowing it wouldn't make the tube grow any. I just asked if he could get one or order one in. Don't think that will happen either. The Big Reno Show is next weekend and they advertise 1& 1/2 acres of exhibitors, anyone wanna put odds on finding a 15 1/2" gas tube in the mess?

Survivalshop.....Thanks for the length tip difference in the AR10. I found this thread here. https://forum.308ar.com/topic/7135-ar-10-vs-dpms-gas-tubes-ftf-issue/?page=1 Gonna try and get one at 15 1/2"

Been trying some Lake City Match with adjustable block

Wash.....you aint slammin that $hit hard enough! Lemme see that that thing I will show you some $hit!

I was waiting for a "no" answer so we could help someone fix their rifle ;)

The 80% lower I finished did not require any machine work involving the bolt catch mechanism or mag well machining. All the 80% lowers I have held in my hands did not require any bolt catch mechanism machining but that does not mean there are not any out there that do. I don't really consider this my "build" (as people like to refer to the assembly process and I find amusing, no offense intended) because I did not build the barrel or bolt or the trigger or the springs or the pins or the gas tube or the buffer or anything else. All I did was "assemble" the lower with parts some other people built. I attached the upper that some more people built. I installed a mag that some other people built. All this crap that was built by some other people other than myself did not work very good when the trigger I did not "build" (I am guilty of pulling it) was pulled. An automobile goes down an assembly line with many people involved, a person buys the car and drives it. They did not build it. They put gas in it and if it breaks down the mechanic who fixes it would not say " I built the car". Its like when I hear someone talk about a "re-weld" gun. It was only welded once so why would it be called a "re-weld"? So I will just keep plugging away at this rifle. I really appreciate all the input and knowledge that people here on this forum share! Remember the Johnny Cash song "One Piece at a Time" ?

OK so in fractions the 0.0900" is about 3/32" and 0.120" is about 1/8" does that sound about right? The gas tube does not extend to the middle of the Cam Pin recess. I have checked the bolt catch and everything looks right and moves easily. When the bolt is latched all the way back and held by the bolt catch the bolt can still be pulled back another 3/8" so the present buffer is not too long. The Mag follower spring is tight when Mag is empty and presses firmly on the bolt catch........... Here is something everyone should try with their AR if they already have not done so. First be sure the gun is empty of ammunition and no round in the chamber, second remove the magazine from the well, third pull the charging handle back and depress the bolt catch to keep the bolt in the open position, forth check again to be sure the gun is unloaded, and fifth grab the hand guard and slam the butt of stock on the floor.........does the bolt slam shut on your gun?

I have a DPMS Buffer and Spring coming, might have it by the weekend. They should be the 5.28 length and 5.41 ounce weight and 12.75 length and 39 coils as advertised and will check them before installing. I will follow the manufactures gas block adjustment instructions with the new parts installed. The gas tube slips into the gas key 3/8" when bolt is fully closed. My camera doesn't take very clear close up pics so cant send pic. The gas tube I have installed measures 15 3/16" and an AR10 is 15 1/2". The extra 5/16" in the AR10 tube length will be too long and would bottom out in the gas key when the bolt is fully closed from the measurements I took. A 15 3/8" would work and not bottom out in gas key. I don't know if the 3/8" engagement into the gas key (which is what the rifle has now) is correct. Maybe if I find a parts Tech. who would measure one at 15 3/8" and have them send it. I don't see any marks on the receiver extension threads. My thinking on the stop of the FTF and cycling correctly is the AR15 spring installed was 11 inches long so the pressure on the bolt changed with a shorter spring and allowed the bolt to move back farther before being pushed back forward by the spring. Also with the adjustable gas block installed the gas pressure could have changed allowing different bolt speed pushing back into the spring.

Extractor is inner and outer spring with oring, I left it alone. It was ejecting a good 4 feet. The gas block is full open and bolt does not stay open after firing last round in mag. With the 308 Standard Buffer Spring Length - 12.75'', 39 coils. and buffer at 4.8 ounces that came with the rifle and the adjustable gas block installed and following manufactures instructions on adjustment of gas the bolt did not stay open after round fired and mag empty. I should get a 5.41 ounce buffer and spring like the ones you have listed above and start all over again with the adjustment of the gas block. The buffer I have now is just over a half ounce lighter and maybe that is enough to cause problems with not holding the bolt open.

Installed spring from my ar15 that measures 11 inches but left the 308 buffer in and loaded 2 rounds in mag. Rifle cycled both rounds but did not hold bolt open with empty mag. So with a lighter spring it cycles, thinking I may have to shorten buffer