Ok guys here is my story… grab some popcorn and a Coke…
I bought a custom 6.8 Upper from a reputable dealer. Got it after waiting many weeks and loved it. Until I brought it to the range. When I drop the bolt release the round jams up in the feed ramps (M4 ramps) and pushes the bullet back into the case. When I pull the C-Handle back and release, it slams the bullet even further back into the case. Repeat as above again and the round chambers but is waaaay seated back into the case & honestly dangerous to shoot.
After I fire the 1st round, usually rounds feed properly but it still has malfunctions. I am using CProducts mags (6 of 'em).
I contacted the dealer and he said “sounds like mag issues. Probably not the upper because everything on the upper is pretty straightforward.” So, I contact Larry @ CProducts, send him my mags, he is testing them now but there seems to be zero problems with the mags. (BTW, CProducts has been GREAT at working with me. They have been very professional and helpful!)
I called the dealer re: my upper on Friday but have not recieved a call back yet.
It is a CMT upper /M4 feedramps. Everything looks ok.
What could it be? I understand the dealer about the upper but what are some possible problems? I’m upset that I have ruined lots of expensive 6.8 ammo w/ this upper & I still have problems. I’ve shot about 200 rounds w/ it so far. V-Max bullets feed fine, everything else jams.
CProducts has put out a lot of bad mags over the last two years. If it were me I would try some other brands regardless of what CProducts tells you is going on with their mags.
I also agree. Different mags would be the very first thing I would try differently. Do you use any of the Magpul anti-tilt followers? Did those come w/your Cproduct mags?
If you can’t answer this question, I’ll understand, whoever built this precision upper for you, did they test fire it for functioning?
This seems to be a very common problem.
One solution that has worked good is to tweak the mag lips so that the bullet tips actually hit the feedramps.
It’s common for the bullet tips to hit low.
Here are a couple pictures of what you want to end up with:
Basically, you bend the front of the lip about 0.020" upwards, tapering back to no change at the rear.
This raises the bullet tip about 0.040", making it hit the feedramps properly.
I suggest either 4" crescent wrench or needle nose pliers, whichever you are more comfortable with…
It kind of bothers me that I may need to modify and tweak my mags simply to get them to function. I like the price of the CProducts mags but if they don’t work properly…
PRI would be the only other option and they charge 2X as much for a mag and I still hear of people bending the feed lips on their mags as well.
This is quite frustrating. Thanks for the repsponses guys. When I get the mags back maybe I’ll try bending the lips.
I agree. It’s hard to know what I have tried or how experienced w/ the weapon I am.
I have the feed problems w/ 1 round loaded, 3, 5, 15, 25, it does not matter how many rounds are in the mag it still jams while feeding.
And I totally agree about the price of the PRI mags.
So fellas, is it POSSIBLE that the problem could be the upper? No one has mentioned that yet. I’m not sure how it could be but I’m not an expert which is why I ask.
Please load all 6 mags with at least 5 rounds.
Lay them all side by side, on their backs so the bullets are pointing upwards.
Take a picture of this and post it here or email it to randall@ar15barrels.com.
What I want to see is the location of the bullet tips in relation to the front of the magazine.
If the bullet tips are sitting low, that’s absolutely the problem.
The mag tweak helps uppers with or without M4 feedramps, but you have to raise the bullet tips a little more for non-M4 ramped uppers.
Here are a couple side view shots.
Notice how the round is sitting higher afterwards.
That’s about how the rounds should look sitting in the mag.
The ones that were lower were having feeding problems.
I do not. I highly doubt that all 6 mags are bad (especially shince Larry is using them without issue). Since you get the same thing with USGI mags, then I think it is your upper (most likely you BCG).
As I posted previously, we’ve seen problems with our C-Product magazine dimensions–some are very tight fitting in our Colt mag wells. On the other hand, we have not had any failures to feed with our PRI mags in Barrett, MSTN, and PRI uppers nor in our 6.8 mm Robinson. I suspect Randall’s advice is quite relevant to your problem and his council should be carefully considered…
I have been at the range with a customer having problems with his C products mags.
He had about 10 of them, maybe it was an even dozen.
ALL had the same problem.
As I tweaked a couple of them with needle nose pliers (not the optimum tool for the job), the problems went away.
The bullet tip absolutely MUST hit the feedramp in order to feed.
If it’s hitting low, you will have problems.
Look at your upper.
Are there little copper marks just below the feedramps from where the bullets were getting jammed?
That’s the tell-tale sign…
CProducts has put out a lot of bad mags over the last two years. If it were me I would try some other brands regardless of what CProducts tells you is going on with their mags.
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That certainly a very broad, general statement. Is this first hand experience or something you have heard? And in your mind, what is a lot?
We have tested the magazine in question in a Bushmaster without problems. Tuesday we are going to Stag Arms and do some testing there. As I have told the customer as well as anyone else who has a problem with one of our products…after we test it if we are wrong we will admit it and make the correction, and replace the defective magazine at no charge. Since we have introduced the 6.8 we have had a hand full that had a problem and everyone was the follower hanging up.
My intent is not to insult you but I think it is not truthful to suggest that CProducts didn’t have a lot of problems with the initial magazines. In addition, people who bought the bad mags were promised 2 good in exchange for 1 bad…and the promise was not kept. The mags I bought ended up getting thrown away rather than deal with CS.
The picture above clearly demonstrates the problem which is the feed lips, not the followers.
Like I said, try other mags before it is decided it is not a mag related issue.
And to answer the question: And in your mind, what is a lot? An entire production run.
In Larry’s defense, the first two pictures above (single mag pictures) are of a PRI mag.
I am not sure what brand the two mags in the 2nd pictures are as those pictures came from someone else.
I don’t own any C-products mags.
It’s not because I don’t want them, but because I can’t get them…
I have have had basically 100% reliability with my CProducts 6.8mm Mags. Not so with the PRI mags I had (stress had because I got rid of them in leu of all CProducts 6.8mm mags). I would try mags from a different manufacturer.
Something I would also consider is changing out the buffer to something heavier. If the bolt/bolt carrier are moving too fast I have found that the cartridge may not be in an ideal mag position when it is picked up by the bolt.
