Help!! Brand new LR-260 and it won't cycle..? Iis something I am doing?

[Birdie_in_Texas]

Took my new DPMS LR-260, 1 day old, out to the range today. First 40 rounds were "Fusion" 120gr factory cheapest thing I could get my hands on just to have something to shoot. Everything seemed fine. Ran a snake thru it every few rounds. Ran out of the 120 gr stuff and started trying to shoot Remington corelokt 140gr factory rounds, and it would fire, but not cycle. Had to run the charging lever manually, and it was some crazy work..

The barrel is 1:8.5 so 140gr should be more than "ok" right? So after 5 rounds, I stopped and put the gun up.

Now am home, but what should I do folks? I see nothing wrong in the chamber, nothing wrong up; the barell..it is a little dirty but cheap ass factory loads, I expect that, but why won't it run the 140's..?

Any help would be very much appreciated fellas..

 

[kilos]

Needs more balls. GAS

 

[Birdie_in_Texas]

i am sorry sir..I do not get the reference..

 

[remiglockoholic]

i am sorry sir..I do not get the reference..

Adjust the gas block

 

[FCS]

All has to do with port pressure, gas volume available to cycle the BCG. 120s are probably loaded with a fairly slow burn rate powder and lot of it to get velocity so plenty of GAS to cycle the BCG. 140s are clearly loaded with a burn rate that is not giving you needed port pressure, gas volume needed to cycle BCG.

 

[Birdie_in_Texas]

i am very new to the world of AR style guns. My 5.56 is an Adams, and is piston but this one is DI, and I do not see anything "adjustable" about this gas block..

Sorry for my newbness..

 

[remiglockoholic]

Post pics

 

[FCS]

Adjust the gas block

Pretty sure the DPMS LR doesn't come with an adjustable gas block.

I'm more inclined to think the ammo does not have proper burn rate powder to cycle the BCG.

 

[Birdie_in_Texas]

All has to do with port pressure, gas volume available to cycle the BCG. 120s are probably loaded with a fairly slow burn rate powder and lot of it to get velocity so plenty of GAS to cycle the BCG. 140s are clearly loaded with a burn rate that is not giving you needed port pressure, gas volume needed to cycle BCG.

Ok, so I need to cross these off the "buy" list.

We are going to reload, so we will just yank the bullet and reload with some Sierra 107gr HPBT's I saw at Gibsons earlier

 

[Birdie_in_Texas]

Post pics

ok..gimme a minute and I will post something..

 

[FCS]

Ok, so I need to cross these off the "buy" list.

We are going to reload, so we will just yank the bullet and reload with some Sierra 107gr HPBT's I saw at Gibsons earlier

I wouldn't go that route. Load heavier bullet and H4350, IMR4350, AA-4350, N-150, N-160 or similar burn rate.

107 is wrong direction IMHO. Additionally the ogive profile on the 107 SMK is probably going to give you issue verses the ogive profile of a 140 SMK, 139 Scenar, 140 Amax, or 142 SMK.

 

[FCS]

ok..gimme a minute and I will post something..

Picture of case head showing how much radius is left on primer would be helpful, both from 120 and 140 gr ammo.

Any bur or ejector swipe on case head, either type of ammo?

 

[Birdie_in_Texas]

Picture of case head showing how much radius is left on primer would be helpful, both from 120 and 140 gr ammo.

Any bur or ejector swipe on case head, either type of ammo?

uh..."ejector swipe?..?

I am sorry..I do not know what that is..

let me get pics of the casings..

 

[Birdie_in_Texas]

well..this new win8 computer doesn't want to recognize my phone!!

I got pictures of everything, but gotta get them off phone..

 

[Birdie_in_Texas]

 

[Birdie_in_Texas]

ok..now i am on the right track

 

[Birdie_in_Texas]

i got the brass laid out here in front of me..several of the casings have flat spots on the necks..and all of these brass have a pretty deep scratch down the side of them from the top of the neck..

 

[Birdie_in_Texas]

ok..the brass laying down is from the 120grain rounds.

Those 4 or 5 on the left standing are the larger 140grain casings.

See the scratch? And the flat spots? I do not think I stepped on any of these when I was picking them up..

 

[FCS]

Picture that shows case head, primer / case junction would be most helpful.

 

[FCS]

View attachment 51996View attachment 51997

ok..the brass laying down is from the 120grain rounds.

Those 4 or 5 on the left standing are the larger 140grain casings.

See the scratch? And the flat spots? I do not think I stepped on any of these when I was picking them up..

Flat spot on neck is from case hitting inside of receiver / barrel extension when extracted.
Scratch on neck is most probably from neck catching the lug raceway on barrel extension upon extraction.
Scratch on body of case is most probably from feed lips of magazine, you can knock down the sharp edge on feed lips to minimize the scratch or go to Pmags.

 

[BLDTYLRY]

You need to lube up the BCG dripping wet. The action will smooth out and everything will start to smooth out after 100-200 rounds.

 

[Birdie_in_Texas]

ok..hope this is good enough pic..

 

[fdkay]

Did you properly clean and lube the rifle before going to the range?
Clean the rifle, lube the bolt and BCG, use a chamber brush to clean the chamber then make sure to clean any debris or dirt from the chamber. By a can of carb cleaner, with the red straw installed on the carb cleaner, hose out the gas tube.
Try again. If it is still mal-functioning, you'll need to start looking else-where.
It may be an improperly sized gas port. It may be blockage in the port or the gas tube, it could be the buffer or spring.

 

[Birdie_in_Texas]

casings top left are the 140grain, the rest are the 120's..

 

[Birdie_in_Texas]

oops..i was wrong..the top left, lower row middle is one of the 120grain casings..

 

[sandwarrior]

You better check something here. Do I see burn cuts in the necks of the 120's? The bright pic to the right of the darker ones laying down. Three of those five cases look like burn cuts through the neck.

Also, what's goofy to me is the primer faces look okay. The cratering on them is deep as hell, though.

If you're gonna do .260 you might look into a lot better brass. Lapua makes the best. Then Norma. Both really expensive. If you can get Winchester, I'd take that any day over Rem. Federal is alright, but tends to be a little soft in the head. Otherwise decent brass though.

 

[oneshot onekill]

To go from functioning perfectly with one properly loaded round to ceasing to function at all with another properly loaded round (and by properly loaded I mean within SAAMI specifications) usually means that something in the gas system has failed or broken. I handle customer service and tech support at an AR Maunfacturer and here are some of the things I've seen with regard to your problem. (1)Carrier key screws broken... They can break and stay in place because they are staked. If they turn there's a problem. (2)Gas block or gas tube loose... Not too common but I've seen it. If the gas block moves in any direction it can cut off the gas. Ive seen gas blocks that moved forward from recoil and that will cut Off the gas. I've seen gas tubes that were never pinned and walked out gradually which will cut off the gas also. (3)Gas rings damaged, missing or with the cuts aligned.
For an AR to completely stop cycling where you have to charge it manually every shot, it should be pretty easy to find the problem.
...FWIW

 

[STI_1911_Guy]

You need to lube up the BCG dripping wet. The action will smooth out and everything will start to smooth out after 100-200 rounds.

^^^^^

This, I had the same exact issue with my LR-260 when i purchased it. It would cycle some of the stuff i had and not others. All that i had to do was just get the BCG dripping wet with oil ( not literally but close) and after about 100-200 rounds it now cycles everything i have tried, including reloads with 120-140gr bullets. Before you go changing anything or trying more involved troubleshooting, just get it wet and run it.

 

[Birdie_in_Texas]

not having deep pockets at all, i did get a box of 142 smk, and a 50-count of nosler brass.

i can get the powder here local, all we have are 3 pounds of cfe223 some winchester 748 and I cannot remember the other..

thanks to everyone that replied. I have learned a great deal of what I need to do, and I will report back!

hopefully tomorrow we can sneak off to TacPro in Mingus and I can run another 60 rounds thru it, dripping ass wet this time..

 

[Cnewhouse48]

I have the same setup with no issues. I have shot both rounds listed and my hand loads also. I have never had any ejection issues. I polished my bolt from day one with a dremal tool and keep my bolt lubed very well. Yours may need to be broke in more.

 

[LongArm]

Make sure its run with alot of lube on the races of the bolt carrier (there are 4 of them 1 o'clock, 5, 7, 10 o'clock) and a very small drop on the rear (butt stock side) of the bolt lugs. Buy a good adjustable gas block ( I like the ones made buy SLR rifleworks). Shoot the hell out of it. My guess is its probably going to shoot well.

 

[Newtrick]

I had cycling issues with mine also at first. Started running the BCG pretty "wet". Issues went away.

 

[sandwarrior]

Birdie_in_Texas

Good find on the Nosler Brass. Norma was the first to make it for them, but I don't know who makes it now. They are sticklers about quality.

When Nosler brass first came out about eight years ago, I talked to a reloading store owner who said it must be crap, because no one bought it after the first bunch. I told him to keep getting it, as the first batches hadn't been shot out. Those first buyers will be back and so will their friends. The stuff moves regularly off the shelves now.

 

[morganlamprecht]

OP, not sure if this is your case but the local Academy here in south tx has 260 Remington 140 Corelokt loads that are labeled 'reduced recoil'...im not sure the difference because i have never bought/shot factory 260 loads (handloads only)...the recoil reduction may be a result of lower pressure loads? idk how they do it

 

[LRRPF52]

.260 Rem is a reloader's affair when looking at gas guns. For those automatically jumping to a conclusion that this is a lack of gas factor, also consider that too much gas on the extreme end can produce the same results, where the gas runs through the system so fast, it doesn't act on the carrier/bolt impingement chamber long enough to transfer interia into the BCG, and it escapes out through the gas vents visible through the ejection port.

What is the dark coloring on your primers? If that is soot, you have major problems with pressure.

The two .260 Rem AR's that I have owned have never seen a factory round, nor will they. Read JP's technical notes on this and you will see the same thing.

.260 Remington in a gas gun = reloader's game, unless you get custom lots produced for you.

 

[Birddog6424]

You need to lube up the BCG dripping wet. The action will smooth out and everything will start to smooth out after 100-200 rounds.

This.

All this rethinking the ammo and gas block is probably premature.

New gun. Shooter new to AR platforms. I bet the farm the bolt is too dry.

99% of the time when a gun comes into the shop and won't cycle, this is the reason. Issues with ammo or too little gas are actually rare in comparison.

Grease up the buffer and spring and lube the hell out of the bolt. I bet it'll run just fine.