Core 15 Rifle chamber issues

gdcpony · October 30, 2017, 05:06 AM

Here's the deal. I can't seem to get a reply from the company so I will ask you all what your thoughts are.

16" barrel Carbine AR15 (their base model) from Core 15 Rifles. It belongs to another Marine in my unit and he asked me to look at it.

At first it would not chamber rounds about 75% of the time when it did, you had to use a wooden dowel and a hammer to get them out most of the time. This is 4 different types of 5.56/.223 Cycling it empty it would stick a bit (it has only successfully fired one round) but nothing hard, just like it needed polished up/broke in a bit. Swapping a bolt from my favorite AR into it resulted in a smooth cycle empty, but no change chambering/ extracting. His bolt in mine ran good all the way through. I polished a couple of the contact points with 1200 grit and her cycling smoothed out empty, no change with a round involved.

So without the ability to make a chamber cast, we went thought and measured the exact rounds that gave us the issue. They would have a shoulder base of .353-.354 (spec is .354). The ones that would cycle would be .352 and under. This leads me to think a worn reamer was used to cut the chamber as the shoulder wears the fastest with them and that also seems to be the jamming point.

I know there are "tight chambers" and have a couple, but this is in no way a match gun, and the dimensions I am looking at are way to tight for a semiauto gun to even think of running. Trying to get an answer out of the company has been frustrating at least. No reply or placed on hold forever and dropped. With the warranty being their real only selling point, I am thinking it is worthless now.

The Marine is looking at a barrel swap as his only real option to get this thing to reliably run. Before he does that, I was looking for other options.

CarJunkieLS1 · October 30, 2017, 05:52 AM

Check it with a set of head space gages. If that checks good just take the barrel to a smith and have them run a reamer in it.

gdcpony · October 30, 2017, 08:05 AM

Would a finish reamer work? My go-no go gauges check out. They measure .352 at the same point in the chamber.

G.barnes · November 1, 2017, 05:25 AM

How long have you been trying to get a hold of the company? In my opinion this is part of what defines a good company from mediocre. Everyone can put out a bad part but how they deal with it is another matter. If it was me I'd get rid of that rifle and get something new from a more reputable company. Yes you'll lose some money, but what if you spend money rebarreling it and something else isn't right with it. Then you have to spend money to fix that.

Mobuck · November 1, 2017, 05:54 AM

"Check it with a set of head space gages. If that checks good just take the barrel to a smith and have them run a reamer in it."

At that point, you have nearly the cost of a new barrel invested with a 50/50 chance of success.

2Apatriot · November 2, 2017, 06:57 AM

I had an issue like this with my Core 15. I was at the Ocala National Forest range and had a round get stuck in the chamber. I had to beat it out. Once I got it out, with the upper off, I dropped a new round into the chamber to see if it would fall out on its own. Nope, I had to knock it out. I ordered a Flex Hone and that solved the issue for me. When inspecting their chamber, it wasn’t very smooth from the factory. But now I have zero issues and it even eats steal case ammo crap.

October 30, 2017, 05:06 AM	#1
gdcpony Member Join Date: March 2, 2010 Posts: 28	Core 15 Rifle chamber issues Here's the deal. I can't seem to get a reply from the company so I will ask you all what your thoughts are. 16" barrel Carbine AR15 (their base model) from Core 15 Rifles. It belongs to another Marine in my unit and he asked me to look at it. At first it would not chamber rounds about 75% of the time when it did, you had to use a wooden dowel and a hammer to get them out most of the time. This is 4 different types of 5.56/.223 Cycling it empty it would stick a bit (it has only successfully fired one round) but nothing hard, just like it needed polished up/broke in a bit. Swapping a bolt from my favorite AR into it resulted in a smooth cycle empty, but no change chambering/ extracting. His bolt in mine ran good all the way through. I polished a couple of the contact points with 1200 grit and her cycling smoothed out empty, no change with a round involved. So without the ability to make a chamber cast, we went thought and measured the exact rounds that gave us the issue. They would have a shoulder base of .353-.354 (spec is .354). The ones that would cycle would be .352 and under. This leads me to think a worn reamer was used to cut the chamber as the shoulder wears the fastest with them and that also seems to be the jamming point. I know there are "tight chambers" and have a couple, but this is in no way a match gun, and the dimensions I am looking at are way to tight for a semiauto gun to even think of running. Trying to get an answer out of the company has been frustrating at least. No reply or placed on hold forever and dropped. With the warranty being their real only selling point, I am thinking it is worthless now. The Marine is looking at a barrel swap as his only real option to get this thing to reliably run. Before he does that, I was looking for other options.

November 1, 2017, 05:25 AM	#4
G.barnes Senior Member Join Date: June 3, 2011 Posts: 182	How long have you been trying to get a hold of the company? In my opinion this is part of what defines a good company from mediocre. Everyone can put out a bad part but how they deal with it is another matter. If it was me I'd get rid of that rifle and get something new from a more reputable company. Yes you'll lose some money, but what if you spend money rebarreling it and something else isn't right with it. Then you have to spend money to fix that. Last edited by G.barnes; November 1, 2017 at 05:35 AM.

October 30, 2017, 05:52 AM	#2
CarJunkieLS1 Senior Member Join Date: October 1, 2013 Posts: 686	Check it with a set of head space gages. If that checks good just take the barrel to a smith and have them run a reamer in it.

October 30, 2017, 08:05 AM	#3
gdcpony Member Join Date: March 2, 2010 Posts: 28	Would a finish reamer work? My go-no go gauges check out. They measure .352 at the same point in the chamber.

November 1, 2017, 05:54 AM	#5
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	"Check it with a set of head space gages. If that checks good just take the barrel to a smith and have them run a reamer in it." At that point, you have nearly the cost of a new barrel invested with a 50/50 chance of success.

November 2, 2017, 06:57 AM	#6
2Apatriot Junior Member Join Date: October 19, 2017 Posts: 1	I had an issue like this with my Core 15. I was at the Ocala National Forest range and had a round get stuck in the chamber. I had to beat it out. Once I got it out, with the upper off, I dropped a new round into the chamber to see if it would fall out on its own. Nope, I had to knock it out. I ordered a Flex Hone and that solved the issue for me. When inspecting their chamber, it wasn’t very smooth from the factory. But now I have zero issues and it even eats steal case ammo crap.