How far does your rifle cycle with the umc ammo. Brass pulled just clear of chamber and jambed? Does it even pull the brass, or is it in there sideways to be cleared . If it pulls brass but doe not clear with umc and works with a premium ammo pickup some other ammo like federal ar223 ammo or pmc. If it works with other ammos then the problems lays with remington. Might call S*W to and see if they have had complants while remmy ammo is being used. Also get the buffer weight for your model and spring lenght and any color markings.
From another forum: M&P 15 Carbine woes.
- Thread starter Bore Rider
- Start date
OP
Bore Rider
Member
It pulls the first round completely free and slings the brass out with authority. It passes the "last round in the magazine BCG lock back" test. It will even cycle a few shots out of a magazine then it goes to ejecting the spent round and either not picking up the next round in the mag or only partially loading the next round causing the gun to jam. The gas seal rings are scrambled and not lined up either. I guess it could be the buffer and spring then since everyone thinks so. I've not changed the buffer/spring though I have an alternate heavy kit that I have yet to install. Like I said previously the original owner didn't have enough knowledge of the internal workings of the gun to change the buffer and spring. I'll get a weight on the buffer and a length of the spring and post it to see if I'm right or wrong.
It will be interesting to see what some milspec 5.56 ammo does in it. Would not be the first time remingtom ammo caused issues. How far is the rifle throwing that first caseing. Mine tends to throw them for the next county or 10 feet. If you can use another persons mag.
Last resort give S&W's CS a call. Guess it could go in for a visit.
Last resort give S&W's CS a call. Guess it could go in for a visit.
Is there a problem with the Magazine lock, if the magazine is not fully inserted or the catch is a little worn maybe it is not holding the magazine up enough to allow the bolt to pick up the next round? Has it been removed or a B.A.D. device incorrectly installed. As I am trying to understand the situation it sounds like everything is working it is just not always picking up the next round from the magazine. Since you have changed all the magazines, have you tried a USGI mag or a Magpul Pmag? You may look at the magazine catch and see if it is incorrectly installed or had the catch cracked or chipped.
Hobie1
Member
This is one for the archives. Could the gas tube gum up as it get's hot? I'm watching this for future use.
Hobie
Hobie
OP
Bore Rider
Member
I will have much more time to tinker with the carbine when I get back to Texas. Living in Illinois isn't exactly conducive to all out gun nuts. I'll keep you guys posted as I try different ammo. If it turns out that the UMC ammo is at fault I have no worries. My RRA, Remington 7615, and my CZ 527 American will digest it just fine.
rojodiablo
Member
- Joined
- Sep 17, 2011
- Messages
- 1,759
- Reaction score
- 1,190
It's possible.......
OP, I will suggest you get a can of brake cleaner and use the little tube to get it down into the gas tube and thru the gas port. It will strip any residues out of the gas port, which very possibly might be the problem.
With no knowledge of initial prep before firing by the original owner, and with no knowledge of which cleaning solvents/ substances you or he might have used, there is a decent possibility that some cleaner has 'gunked up' in there somewhere. My guess is in the gas block junction, as it is the smallest spot and most likely to give you an issue.
For general information to ALL AR users, please do not use foam bore cleaners in the rifles. It leaves a gunk residue, and this is a common issue when a barrel is treated with the foam cleaner.
When stripping out an upper, I will actually plug the barrel tip, face the barrel downward, and clean down from the top with the brake cleaner. A lot of shots down the gas tube, and then see what collects down on the cleaning patch in the tip of the barrel. If the rifle was acting like the OP's unit, you usually see some stuff coming out of that junction in the gas block, and after thorough drying, re lubing and firing, the rifles usually work properly.
OP
Bore Rider
Member
I removed the gas block and used a generous amount of Break Free to clean the gas tube. I then took a pipe cleaner to it until I had no additional signs of fouling. I reinstalled the gas block and shot another healthy load of Break Free down the tube while looking down the bore. I saw a flood of BF come out of the gas port at that point.
JaPes
Member
OP
Bore Rider
Member
Well I'm back with some good news and some bad news. I found some 223 ammo that will work in my carbine. It is made by American Eagle and it works great. On the other side, I purchased some PMC ammo and it did not function. I spoke with a gunsmith at the range and, without even looking at my M&P, he said my problem exists in the gas port on the barrel. I'll continue to fire 5.56 until I return to Texas. At that point I'll take it to my gunsmith for repair.
JaPes
Member
Bore Rider,
Even though you bought yours in a private sale, give S&W a call. They'll know the model number from the SN. They might take care of it under the lifetime service warranty.
Even though you bought yours in a private sale, give S&W a call. They'll know the model number from the SN. They might take care of it under the lifetime service warranty.
I have learned something from my own rifle. If the gas block has been moved or replaced or just not assembled right, it will short stroke and cause this same problem. FWIW it is something to think about!
Direct quote from smith and wesson as I asked them this question "The optimum configuration is for non-alignment as the gas is forced in one direction creating greater pressure and velocity.
Aligned the gas will have less pressure and velocity as it will take the path of least resistance.
Have Good Day
Michael"
Kodiakco
Member
Here is something everyone may be interested in. AR-15 Cutaway Pictures
