DPMS LR-308

Rsquared · June 13, 2016

And GM won't void the warranty if you mod one of theirs? Don't bet on it.

And....my 150 came with almost 400 factory horses. No hot-rodding needed.

But.....the Ford/Chevy pissing match has been going on for decades. :laffs:

DD_Raptor · June 13, 2016

Oh man, you mean I bought a FORD DPMS rifle? CRAP!!!

Edited June 13, 2016 by DD_Raptor

survivalshop · June 13, 2016

1 hour ago, mrmackc said:

Are we now talking about apples and oranges being the same?

APPLES?

DPMS Gas Tube/AR 15/16

  Pistol 6-5/8

Carbine 9-3/4

Mid-Length 11-3/4

Rifle 15-1/4

          ORANGES?

Armalite lengths,

Rifle ( 308 ) ----- 15.5 "

Carbine ( 308 )--12 1/16"

super SASS Carbine ( 308 )--11"

Super SASS< Rife (308 ) ?

Mid ,( 223 )------------------ 11 3/4"

Carbine ( 223) --------------- 9 3/4 "

Rifle ( 223 ) ------------------- 15 3/16"

National Match--------------- ?

Whats your point ?

DD_Raptor · June 13, 2016

AH I see your point survivalshop on the mid hence 16" barrel. 11 3/4" it is.

mrmackc · June 13, 2016

Maybe I should have used a Tundra in the example of voiding a warranty pickey.. pickey,NIT PICKEY. Found on the road dead, Fix or repair daily folks are really thin skinned. I wonder why?

Edited June 13, 2016 by mrmackc

DD_Raptor · June 13, 2016

Some pictures for you.. Looks like it's 9 3/4" to me, I put it ~ where you said it should be an it was ~ 3/8" off. Making the total length 10 1/8"???? That's not a listing. lol Does look like some blow by on the tube.

Edited June 13, 2016 by DD_Raptor

DD_Raptor · June 13, 2016

And one more. Look at the stake marks...

DD_Raptor · June 14, 2016

Ok a few more pictures for you peeps.

In the 1st picture on just my eye balling, I think this is where the block and tube should be to align which is a little different from the setting they installed. But that would make the gas tube even shorter in the upper. In the second picture if you can tell, the indents in the barrel are way off from the alignment holes of the block. I am wondering if they installed the wrong block on this setup. I mean I would think the barrel indents would mean that's where the Allen screws should go when tightening. Maybe I'm wrong.

I had to file the barrel a little bit just to get the gas block back on... WOW.

mrmackc · June 14, 2016

5 hours ago, survivalshop said:

Whats your point ?

It was a question. One table is for DPMS AR 15 and the other for Armalite .308 ,his rifle is a DPMS LR308. Will either gas tube fit a DPMS 308 rifle of his barrel length?

washguy · June 14, 2016

DD if your serial number has a k in the serial number its not a factory rifle ...it was a stripped lower that someone built up Wash

On 3/26/2015 at 10:33 AM, washguy said:

The answer is easy. DPMS adds a "K" to the serial number of lower received that are sold as parts.

Yep, last digit in the serial is a K if it was made as a stripped lower. They don't deviate from that.

Edited June 14, 2016 by washguy

survivalshop · June 14, 2016

12 hours ago, mrmackc said:

Maybe I should have used a Tundra in the example of voiding a warranty pickey.. pickey,NIT PICKEY. Found on the road dead, Fix or repair daily folks are really thin skinned. I wonder why?

I think he was pointing out that any manufacturer will void a warranty if product is molested .

7 hours ago, mrmackc said:

It was a question. One table is for DPMS AR 15 and the other for Armalite .308 ,his rifle is a DPMS LR308. Will either gas tube fit a DPMS 308 rifle of his barrel length?

AR 15 & LR 308 use the same Gas Tubes , but Armalite AR 10 & Armalite 5.56 use different ones , the only Tube length used in any Armalite rifle that is the same as an AR 15 is the Carbine used in both AR 15 & Armalite Carbine in 5.56 rifles, is the point of the list & is shown for comparison , so yes , its why I said there is something not right in with the posters Gas Tube length or Barrel.

The list should read DPMS LR308/AR15 for clarification. What I copied & pasted read that way , but some how got left out , I'm sure it was me , that did something to screw it up . :laffs:

We have seen here over the years , some Barrel makers even have their own Proprietary Gas Tube lengths on their rifle builds .

Edited June 14, 2016 by survivalshop

survivalshop · June 14, 2016

I purchased a complete DPMS LR 308 Lower Receiver assembly , no Upper assembly & it doesn't have a "K" in the serial number , but unknown if it was part of a complete rifle , so you never know .

Where are the Components that were removed from this rifle ? What type of Gas Block was on the Barrel to begin with.

The pockets drilled for the Gas Block do not look factory made , if they are off , the gas Block can never be aligned properly, a Clamp on type will remedy the issue . Some Barrels have the Gas Block stop flange on the Barrel , set to be able to use A2 Hand Guards & will have the Gas Block set away from it for the front HG cap , a small gap , I will have to measure the thickness of the Cap to show the measurement , but in most after market Barrels are made so the Gas Block seats right against the Barrels stop Flange for the Gas Block. It may not be much , but can throttle the Gas port enough to cause issues .

I would still look further into the Barrel Nut , just to make sure the Barrels Extension Flange is seated correctly & the alignment Pin is seated into it grove in the Upper Receiver.

Your issue is one of a couple of things ,

-Barrel has a Gas Block area or gas Port incorrect . if its a true unmolested DPMS LR 308 , Carbine Gas system ,Barrel , this is kinda doubtful , regardless of Gas Block change .

- Hand Guard assembly incorrectly assembled ( Barrel Nut assembly ) . It has to be removed to inspect.

- DPMS did some strange stuff some times & this may require proprietary components .

DD_Raptor · June 14, 2016

9 hours ago, washguy said:

DD if your serial number has a k in the serial number its not a factory rifle ...it was a stripped lower that someone built up Wash

Yep, last digit in the serial is a K if it was made as a stripped lower. They don't deviate from that.

There isn't a K in the serial number. So I assume its factory as I have the box it came in and the serial number on the box and lower match.

Edited June 14, 2016 by DD_Raptor

DD_Raptor · June 14, 2016

Since I don't have the tools to do that, guess I'll put it back together and let the pawn shop dude handle it. If he can't figure it out then I want my money back. :cool:

I will point him to this thread.

mrmackc · June 14, 2016

3 hours ago, survivalshop said:

I think he was pointing out that any manufacturer will void a warranty if product is molested .

AR 15 & LR 308 use the same Gas Tubes , but Armalite AR 10 & Armalite 5.56 use different ones , the only Tube length used in any Armalite rifle that is the same as an AR 15 is the Carbine used in both AR 15 & Armalite Carbine in 5.56 rifles, is the point of the list & is shown for comparison , so yes , its why I said there is something not right in with the posters Gas Tube length or Barrel.

The list should read DPMS LR308/AR15 for clarification. What I copied & pasted read that way , but some how got left out , I'm sure it was me , that did something to screw it up .

We have seen here over the years , some Barrel makers even have their own Proprietary Gas Tube lengths on their rifle builds .

Okay, thanks for the clarification,

Are we now talking about apples and oranges being the same?

APPLES?

DPMS Gas Tube/AR 15/16

Pistol 6-5/8

Carbine 9-3/4

Mid-Length 11-3/4

Rifle 15-1/4

ORANGES?

Armalite lengths,

Rifle ( 308 ) ----- 15.5 "

Carbine ( 308 )--12 1/16"

super SASS Carbine ( 308 )--11"

Super SASS< Rife (308 ) ?

Mid ,( 223 )------------------ 11 3/4"

Carbine ( 223) --------------- 9 3/4 "

Rifle ( 223 ) ------------------- 15 3/16"

National Match--------------- ?

COBrien · June 14, 2016

I read it this way:

One could, if need be, use an Armalite gas tube on a DPMS rifle to get the needed length if something non-standard is required.

For example, a DPMS rifle with a mid-length gas system would have a gas tube 11 3/4" in length. If someone were to install an Armalite gas block, there is a chance an Armalite .308 carbine gas tube (12 1/16" in length) could be used to make up the approximately 3/8" difference -- it would actually be more like 5/16".

However, the OP's rifle has a 9 3/4" gas tube, which would require a 10 1/8" gas tube. That is, if it is, in fact, 3/8" too short. I don't see 10 1/8" listed as a "standard length" for either DPMS or Armalite rifles of any caliber.

I am still new to all AR rifles, so I may be way off base here, but that's what it looked like to my admittedly uneducated brain.

survivalshop · June 14, 2016

7 minutes ago, COBrien said:

I read it this way:

One could, if need be, use an Armalite gas tube on a DPMS rifle to get the needed length if something non-standard is required.

For example, a DPMS rifle with a mid-length gas system would have a gas tube 11 3/4" in length. If someone were to install an Armalite gas block, there is a chance an Armalite .308 carbine gas tube (12 1/16" in length) could be used to make up the approximately 3/8" difference -- it would actually be more like 5/16".

However, the OP's rifle has a 9 3/4" gas tube, which would require a 10 1/8" gas tube. That is, if it is, in fact, 3/8" too short. I don't see 10 1/8" listed as a "standard length" for either DPMS or Armalite rifles of any caliber.

I am still new to all AR rifles, so I may be way off base here, but that's what it looked like to my admittedly uneducated brain.

Your not off base , its apparent something is not right with the DD_Raptor's set up , we have seen Barrel Manufacturers or Firearms companies that have the Barrels spec'ed to AR 10 Spec's , for instance , Fulton Armory's early Kreiger Criterion Barrels , of which I have two with rifle length Gas systems , that use the std AR 15 Rifle length Gas Tubes , that's not the case any more , they are using Criterion Barrels now, but require an AR 10 , Rifle length Gas Tube & some how failed to mention the change when they did it . We had several here that had to change to the AR 10 rifle length size ( they offer a longer Gas Tube now & say on their sight its needed ) to rectify the same issue DD_Raptor is experiencing now , but his seems to be something else , which has not been pin pointed as of yet .

Rsquared · June 14, 2016

21 hours ago, DD_Raptor said:

Oh man, you mean I bought a FORD DPMS rifle? CRAP!!!

Nope. You're alright. Everybody knows that Fords are the Armalite's. :laffs:

survivalshop · June 14, 2016

34 minutes ago, Rsquared said:

Nope. You're alright. Everybody knows that Fords are the Armalite's.

:lmao:

DD_Raptor · June 15, 2016

18 hours ago, Rsquared said:

Nope. You're alright. Everybody knows that Fords are the Armalite's.

Now that funny... :laffs:

DD_Raptor · June 15, 2016

Update: I took it to the pawn shop dude and showed him the gas tube length. He agreed it look short. He immediately (not busy there) took the gun back to their gun shop while I waited.

About 30 minutes later he came back and said he changed the gas block to a YHM and gas tube to a CMMG. He said at first the though it was a littles longer but it wasn't, so he changed it anyway. He said he fired off 5 rounds without problems and it locked back after last shot.

In the picture below the tube looks even shorter, it looks like he moved the block back a bit. Now I am just comparing it to the little circle on the bottom there. So the is really no change in the length of the tube. I guess I'll just have to wait to see for my self one I can get back to the farm, which right now is looking like about the 8th of July. :-(

Top picture now Bottom before

blue109 · June 15, 2016

Could have just been the gas block. Get 'er out and do some shooting!

survivalshop · June 15, 2016

Gas Block may have been not centered over the Gas Port correctly , but I'm not very confident with your Gun Smith . Carbine Gas system has a lot of Gas signature pressure , so it may work that way , but again , we have no idea what it was before or really what he did . Please keep us informed .

DD_Raptor · June 15, 2016

1 hour ago, survivalshop said:

Gas Block may have been not centered over the Gas Port correctly , but I'm not very confident with your Gun Smith . Carbine Gas system has a lot of Gas signature pressure , so it may work that way , but again , we have no idea what it was before or really what he did . Please keep us informed .

I don't think he's an actual gun smith by trade, seems knowledgeable, but that doesn't make a gun smith no doubt. I am thinking he put the block about where I had it eyeballed on one of the above pictures. Anyway we shall see. Also I mentioned the barrel nut extension area but he just kind of blew that off. It was like Really!

If I still have problems I guess I'll spring for an armorers wrench and upper or lower vice block or both? And Suggestions would be appreciated.

And I appreciate you peeps taking the time to assist me figuring this out.

Edited June 15, 2016 by DD_Raptor

survivalshop · June 16, 2016

Upper vice Block for an AR 308 & Head Space Gages are some things to have in your tool box . Your Hand Guard may have come with a Nut Wrench, depends , could need just a DPMS LR 308 Nut wrench , hard to say , you could always email or call Troy or even check their Web sight for the info .