AR15 Trigger / Hammer Dent

4T4MAG · November 4, 2015, 11:39 PM

I'm having issues with the trigger / hammer on my ar 15. The front of the trigger and hammer meet on one small part of the engagement where it has a small dent. It's like the hammer and trigger do not fully contact each other. The area where the hammer and trigger rub hard on one side. It is a new trigger with only 60 rounds fired. I bought it a few years ago and finally used it. It is a cmmg LPK. It makes for a really, really rough trigger pull. A lot more rough than any LPK trigger I have ever had before.

Could the issue just be the trigger and hammer were not machined straight in the beginning OR could the issue be the Spikes lower, possibly out of spec?

marine6680 · November 5, 2015, 07:39 AM

Take pictures and point out what you are referring to, that will help.

Mobuck · November 5, 2015, 07:58 AM

If it's something like a manufacturing defect. send it back to CMMG

4T4MAG · November 5, 2015, 12:51 PM

Here is a picture. On the top left there is a gouge or real rough spot. I'm sure it was not there before I fired it a few times. I would return it to CMMG, I bought it at a LGS and have no records. Not that I care about this trigger, I don't want to throw in a Geissele and have this sort of prob.

I'm trying to reason my way through it, is it bad heat treat, hammer trigger were not mfg. straight, or lower out of spec. What would trained logic say?

Edit 1. I don't feel in any way slighted toward any of the companies. I try to figure out what the problem is then find the remedy. I know things happen. I've had 4 other spikes lowers, all have been great. I've used cmmg on several other builds and they have all been great. I'm trying to rule out my own stupid mistakes.

Mobuck · November 5, 2015, 04:36 PM

There's definitely something wrong with that part but I'm having a problem understanding your real question.
If you're going to "throw" a high dollar fire control group at the lower, what diff does the current FCG make? If you're asking whether your pin holes are square, I don't know how we can help with that. It would be a very rare thing if a name brand lower had seriously out of spec trigger/hammer pin hole alignment.

rickyrick · November 5, 2015, 09:12 PM

Run of the mill hammer and triggers are cheap enough, just chuck it and put new ones

marine6680 · November 6, 2015, 12:49 AM

Contact CMMG... See if they will send out a new trigger and hammer. Just explain that after X number of rounds, the hammer and trigger sear interface has worn severely and unevenly.

Probably bad heat treat or something.

I like CMMG triggers, they have always been a step above for a mil spec trigger.

If you do not get a replacement from them, then there are options.

The ALG options are good to go. I would say that their QMS is on par or a bit better than a good CMMG... The ACT is superior to a good CMMG trigger.

Or you can just get a standard mil spec trigger, I'm sure you can find one for pretty cheap.

4T4MAG · November 17, 2015, 02:27 PM

I have used CMMG in a few builds. I've never had an issue. This time around, I contacted CMMG and they were very quick to send out a new hammer and trigger. Excellent customer service. I put my lower in a jig to make sure that all the holes line up, everything was perfect. Thanks all for your help.

November 4, 2015, 11:39 PM	#1
4T4MAG Senior Member Join Date: April 28, 2009 Posts: 162	AR15 Trigger / Hammer Dent I'm having issues with the trigger / hammer on my ar 15. The front of the trigger and hammer meet on one small part of the engagement where it has a small dent. It's like the hammer and trigger do not fully contact each other. The area where the hammer and trigger rub hard on one side. It is a new trigger with only 60 rounds fired. I bought it a few years ago and finally used it. It is a cmmg LPK. It makes for a really, really rough trigger pull. A lot more rough than any LPK trigger I have ever had before. Could the issue just be the trigger and hammer were not machined straight in the beginning OR could the issue be the Spikes lower, possibly out of spec? Last edited by 4T4MAG; November 5, 2015 at 12:00 AM.

November 5, 2015, 09:12 PM	#6
rickyrick Senior Member Join Date: March 15, 2010 Posts: 8,236	Run of the mill hammer and triggers are cheap enough, just chuck it and put new ones __________________ Woohoo, I’m back In Texas!!!

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November 5, 2015, 07:39 AM	#2
marine6680 Senior Member Join Date: July 24, 2012 Location: Parker, CO Posts: 4,594	Take pictures and point out what you are referring to, that will help.

November 5, 2015, 07:58 AM	#3
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	If it's something like a manufacturing defect. send it back to CMMG

November 5, 2015, 04:36 PM	#5
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	There's definitely something wrong with that part but I'm having a problem understanding your real question. If you're going to "throw" a high dollar fire control group at the lower, what diff does the current FCG make? If you're asking whether your pin holes are square, I don't know how we can help with that. It would be a very rare thing if a name brand lower had seriously out of spec trigger/hammer pin hole alignment.

November 6, 2015, 12:49 AM	#7
marine6680 Senior Member Join Date: July 24, 2012 Location: Parker, CO Posts: 4,594	Contact CMMG... See if they will send out a new trigger and hammer. Just explain that after X number of rounds, the hammer and trigger sear interface has worn severely and unevenly. Probably bad heat treat or something. I like CMMG triggers, they have always been a step above for a mil spec trigger. If you do not get a replacement from them, then there are options. The ALG options are good to go. I would say that their QMS is on par or a bit better than a good CMMG... The ACT is superior to a good CMMG trigger. Or you can just get a standard mil spec trigger, I'm sure you can find one for pretty cheap.

November 17, 2015, 02:27 PM	#8
4T4MAG Senior Member Join Date: April 28, 2009 Posts: 162	I have used CMMG in a few builds. I've never had an issue. This time around, I contacted CMMG and they were very quick to send out a new hammer and trigger. Excellent customer service. I put my lower in a jig to make sure that all the holes line up, everything was perfect. Thanks all for your help.