PMC XTAC won't feed into my DDM4

[cheeseburger1976]

I have always shot .233 and have recently switched my "stash" over to primarily .556
Any of the .556 with a green tip PMC, IMI, etc just won't feed into the chamber. The actual green tip of the bullet keeps getting stuck in between the locking lugs. If I let the charging handle fly a few times it will finally cut through and make its way into the chamber. But obviously this is not reliable, is this a common issue? How would I get this fixed?
Thanks in advance
Mike


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[ggammell]

Have you tried any other 5.56 brands?

[cheeseburger1976]

Yep, IMI, federal, Magtech. It seems to only be anything with the green tip I'm guessing due to the little bit of added length?


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[Shao]

My DDM4V1 and V7 both eat XTAC 855 like they're Skittles. What's the lot number on your PMC? If no green-tip will feed, then my guess would be that it's a byproduct of the m855 round having a pointier nose/possibly having a slightly longer OAL... How that correlates to your problem is beyond me. Someone with more knowledge on feeding/bullet shape may step in here, verify if my theory holds any water, and then probably be able to fix you up. I don't claim to be an expert, but when was the last time you changed your buffer spring? Is your gun clean?

[cheeseburger1976]

My DDM4V1 and V7 both eat XTAC 855 like they're Skittles. What's the lot number on your PMC? If no green-tip will feed, then my guess would be that it's a byproduct of the m855 round having a pointier nose/possibly having a slightly longer OAL... How that correlates to your problem is beyond me. Someone with more knowledge on feeding/bullet shape may step in here, verify if my theory holds any water, and then probably be able to fix you up. I don't claim to be an expert, but when was the last time you changed your buffer spring? Is your gun clean?

Gun is clean, it is about five years old and only has a couple thousand rounds through it I guess it cannot hurt to change the buffer spring for starters. I will take any advice that comes my way I appreciate your help.


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[ptmccain]

Weird, I'm wondering if it could be a bad lot of ammo. My DDM4 have never had any chambering problems with anything I've used, including the PMC XTAC ammo.

[markm]

Yep, IMI, federal, Magtech. It seems to only be anything with the green tip I'm guessing due to the little bit of added length?

The Ogive on SS109 bullets is very different than a 55 gr FMJ or a Sierra Matchking for example. The bullet will tend to be skinnier towards the tip and this is likely why the slots in the Barrel extension are grabbing it. That said, this should not be happening.

You need to contact DD and have them check it out.

[JBecker 72]

If it's multiple types of M855 you should contact DD and have them fix it.

[Shao]

The Ogive on SS109 bullets is very different than a 55 gr FMJ or a Sierra Matchking for example. The bullet will tend to be skinnier towards the tip and this is likely why the slots in the Barrel extension are grabbing it. That said, this should not be happening.

You need to contact DD and have them check it out.

Agreed. After reading through your posts, there seems to be about a 0% chance that it's the ammo brand that you're using. I would still swap buffer springs out first since it's a $3 part and see what that does. Maybe there isn't enough "oomph" left in your old spring. Could that be a possibility?

[fifthward]

Not feeding during live fire?? Or hanging up if hand cycled?

[markm]

I assume this is with more than one "clip" right? And is it happening on both sides of the mag feed? Right and Left?

[PA PATRIOT]

I assume from your post that this is the first time your shooting M855 (PTAC) out of this rifle, so some further information is needed for your set-up,

What style BCG are you using M-16 or a Commercial semi auto style?
What type of recoil spring are you using and who many rounds down range has the spring seen?
What buffer weight are you using?
Can you post a picture of the feed ramps and then one of the malfunction? (Please be 100% safe while doing so)

Then we maybe able to help you further.

[The M]

Is it the same problem when feeding from both sides of the mag?

[Shao]

I assume from your post that this is the first time your shooting M855 (PTAC) out of this rifle, so some further information is needed for your set-up,

What style BCG are you using M-16 or a Commercial semi auto style?
What type of recoil spring are you using and who many rounds down range has the spring seen?
What buffer weight are you using?
Can you post a picture of the feed ramps and then one of the malfunction? (Please be 100% safe while doing so)

Then we maybe able to help you further.

Well I would assume it's a FA carrier since it's DDM4. It sounds like he's never changed the spring. Agreed though, we need more info.

[GH41]

"If I let the charging handle fly a few times it will finally cut through and make its way into the chamber"

Doing this is a bad idea!!! You could be beating the bullet back into the case. You are increasing the possibility of a bad thing happening..... In your face!

[RMiller]

I'm assuming it's a factory DD rifle.

Exactly, what mags are you using? Have you used more than one? If not try another, or even a different brand.

[cheeseburger1976]

I assume this is with more than one "clip" right? And is it happening on both sides of the mag feed? Right and Left?

I have tried new pmags and it still does it


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[cheeseburger1976]

I'm assuming it's a factory DD rifle.

Exactly, what mags are you using? Have you used more than one? If not try another, or even a different brand.

It is a factory Daniels and I am using Magpul second-generation magazines I thought maybe the springs were worn out so I tried new ones and it still does the same thing


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[markm]

I have tried new pmags and it still does it


Yep... need to contact DD to get it looked at.

[cbx]

Check the bolt face to see if any thing is wrong there.

The lugs you are talking about, are they lugs for the bolt or the chamber?

[RMiller]

Yep... need to contact DD to get it looked at.

I agree.

[cheeseburger1976]

Check the bolt face to see if any thing is wrong there.

The lugs you are talking about, are they lugs for the bolt or the chamber?

Chamber lugs , I will get a photo tonight


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[Shao]

"If I let the charging handle fly a few times it will finally cut through and make its way into the chamber"

Doing this is a bad idea!!! You could be beating the bullet back into the case. You are increasing the possibility of a bad thing happening..... In your face!

Yes, I was going to mention that earlier. When I first got into the AR platform, I didn't realize that repeatedly chambering rounds was a bad idea. I ruined a perfectly good box of Winchester Ballistic Silvertip testing out a new build because I didn't have any dummy rounds on hand. I would say 18 of the 20 rounds suffered from dangerous bullet setback and 8 of the 20 ballistic tips broke off. I would either throw those rounds away or at least measure them to make sure none of the bullets got backed into the case - and even then, if they passed - I would only use them as range rounds.


Chamber lugs , I will get a photo tonight


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Excellent... Regardless of the problem, it sounds like the rifle or at least the upper needs to be sent back to DD ASAP.

[cheeseburger1976]

Thanks for the heads up, I will thrown those rounds out, only tried 2 of them


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[PA PATRIOT]

Ok, so it sounds like you switch out the buffer spring with a new one (New USGI hopefully) and you using PMag's so my last question is have you tried a plain old USGI magazine and what buffer weight are you using? Also are you running the BCG well lubed and is there any damage to the bolt lugs?

[Beat Trash]

I have three DDM4's in the safe. They all eat PMC, IMI, PU and LC M855 ammunition with no issues. I'd strongly suggest you contact DD customer service and talk with them.

[Heavy Metal]

Sounds like sharp corners on the cut-outs in the extension at the top of the feed ramps.

I would let DD deal with it.

[Singlestack Wonder]

Bottom line.....Contact Daniel Defense......

[cheeseburger1976]

Bottom line.....Contact Daniel Defense......

Just sent the email followed by a phone call, waiting for response


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[vicious_cb]

Is your buffer spring worn out? How much resistance is there when you pull back the charging handle?

[cheeseburger1976]

Joe from Daniel defense just called .....exceptional service. Sending me out a shipping label in a couple days to get it sent to them


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[ptmccain]

Excellent.

I was just about to suggest you contact DD.

:)

[Onyx Z]

Joe from Daniel defense just called .....exceptional service. Sending me out a shipping label in a couple days to get it sent to them


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You will not be disappointed when dealing with DD customer service.

[Iraqgunz]

Correct answer should have been contact DD after it was mentioned that it occurs with multiple ammunition types. We will revisit this once it is resolved.