LMT 10.5's rock

Slavex

Slavex

Morning Star, The Lightbringer
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oh wait no, they don't. at least not the brand new one at the range today.
so what's the most common reason for them to not cycle properly? I don't think it ever managed to eject and feed the next round once. about 5 different types of ammo were used in it. all factory stuff too, no reloads. Gun is brand new as mentioned, lubed up a ton, bolts were swapped, still no joy. I know that it ejected some times, but never fed. So gas block not lined up with the hole in the barrel is my guess. or #### in the hole maybe?
 
I pumped 200 rounds non stop through my 10.5 at the other end of the range with no probs and got her smoking hot.

Was that the MRP with the fixed sight?
 
Seems like -

Seems like its short stroking - lots of info here using search-

:ar15:
swingerlh.gif
 
Get your gas port checked, definitely sounds like its undersized.
What types of ammo and what type of buffer are you running? I believe LMT reccomends a CAR buffer for the 10.5" guns but im not 100% on that. Phone them up.

I would head over to Lightfighter, they have a large knowledge base that would probably get you squared away.
 
I run both H and car buffers interchangeably in my 10.5 and 14.5 LMTs and never had a hiccup other than with 5.56 75gr TAP in the 10.5 (slow burning powder doesn't like super short barrels and heavy buffers).

Another thought: was this a complete sold gun? They would have been test fired at the factory, if so.
 
Odd, maybe a gas problem. You check the carrier? or is the key lose? I have a couple of 10.5s LMTs and a MRP never had any issues with them with all sorts of different types of ammo.
 
Have a 10.5" Defender bought off the EE 8 months ago. Loves any factory ammo and my reloads using 55 grn FMJBT. Never had an issue.
If the "new LMT" mentioned is a complete upper & lower, instead of guessing, one may suggest to the owner to bring it back to his selling dealer. LMT down south has excellent customer service and I assume the same goes true for LMT dealers in Canada. From my experience, Questar's staff are extremely helpful. Happy shooting!!!:canadaFlag::ar15:
 
Slavex said:
oh wait no, they don't. at least not the brand new one at the range today.
so what's the most common reason for them to not cycle properly? I don't think it ever managed to eject and feed the next round once. about 5 different types of ammo were used in it. all factory stuff too, no reloads. Gun is brand new as mentioned, lubed up a ton, bolts were swapped, still no joy. I know that it ejected some times, but never fed. So gas block not lined up with the hole in the barrel is my guess. or s**t in the hole maybe?
Click to expand...

If you "lubed up a ton" it is probably over oiled. Clean and degrease and try it again.
 
LMT 10.5 barrels have a relatively smaller gas port ( .071 ) compared to other barrels I have gauged. For example, Noveske and WOA 10.5s are a much larger .079 to .080 )

You mentioned you tried 5 different types of ammo. Where they all .223 SAMMI or 5.56 pressure stuff ?

I had the same problem you are having with a new LMT 10.5 . When I called LMT they informed me that the gas port is the size it is to optimize use with 5.56 NATO and with or without a suppressors. I got the "why are you not running 5.56 NATO pressure ammo in that rifle"

I have been running only 5.56 and my LMT 10.5 runs like a top now even with a heavy Enidine ( between a H and H2 in weight )

I highly doubt your gas block is misalign in your LMT
 
Never had an issue with my 10.5 LMT upper with a Full Auto Carrier and a ST-T2 buffer, pretty much the heaviest combo shooting garbage AE 55 grain (and others) with no issues.
 
Slavex said:
oh wait no, they don't. at least not the brand new one at the range today.
so what's the most common reason for them to not cycle properly? I don't think it ever managed to eject and feed the next round once. about 5 different types of ammo were used in it. all factory stuff too, no reloads. Gun is brand new as mentioned, lubed up a ton, bolts were swapped, still no joy. I know that it ejected some times, but never fed. So gas block not lined up with the hole in the barrel is my guess. or s**t in the hole maybe?
Click to expand...

Sounds like undergassing.

loose gas key, misaligned gas tube (that creates drags on the bolt carrier) and undersized gas port. FSB is aligned by a jig, they are usually aligned properly.
 
First off, not my gun. Next, first attempts were with factory lube, then as testing progressed more lube. I've never seen an AR that won't run wet so I doubt over lubing is the issue.
Apparently using 5.56 is the next test. Although as mentioned there was another down the line running fine.
Complete factory new gun. I'm guessing gas issue too.
 
i had the same problem shooting 223 at the beggining. After a couple boxes of 556 it has not had a single problem in 1500 or so rounds. At first it couldnt cycle at all.
 
Not my gun either, but I took a few stabs at it.

It's something on the front end.
I ran some zippy LE 5.56 though it, different buffer, different bolt carrier assembly. There is not enough gas making it to the carrier to cycle the action completely. The bolt is coming back enough to reset the trigger, but not far enough to eject the fired casing. The gas tube seemed aligned.
It probably didn't help that the owner had not cleaned it at all prior to shooting it.
 
Mike K said:
Not my gun either, but I took a few stabs at it.

It's something on the front end.
I ran some zippy LE 5.56 though it, different buffer, different bolt carrier assembly. There is not enough gas making it to the carrier to cycle the action completely. The bolt is coming back enough to reset the trigger, but not far enough to eject the fired casing. The gas tube seemed aligned.
It probably didn't help that the owner had not cleaned it at all prior to shooting it.
Click to expand...


This :HR:
 
After mulling over it a bit more, one thing that I did not check was if the barrel was properly aligned. That quick change feature of the MRP barrel adds another possible problem area. Yanking it all apart and putting it back together and torquing everything back into place would be worth doing.
 
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