Feedramp issues

[oldsoldier29]

Good morning all, I have a technical question. I wnet shooting this weekend, and ran into some issues. I was getting misfeeds, and, initially, though it may be the magazines. After trying several different ones, I was STILL getting the same issues. When I got home, my brother & I started looking into it-it couldnt be the mags, as we replicated it with several different ones-ones I KNOW are reliable. So, we found out that it is a feed ramp issue. I have an M4 receiver with a rifle barrel extension. what is happening is that the rounds are catching on the lip (see attached pic), causing the misfeeds (bullet gets pushed into the cartridge itself). I thought I had seen similar issues here with other people, but couldnt find it.
Essentially, is there someone who can grind down & polish the feedramps? Or do I need to order new parts?

 

[Admin]

Pic?

 

[oldsoldier29]

http://s42.photobucket.com/albums/e328/oldsoldier29/?action=view&current=DSCN0622.jpg I dont know if the pic posted above or not, so I am hoping that this link will show it.

 

[Admin]

That could be the culprit. What brand of upper is it?

With the actual lip there I am surprised it passed QA.

 

[oldsoldier29]

I got it from Remsport, but I ORIGINALLY had a different upper on there, that was an Olympic Arms, I believe. I just had the upper receiver (not the barrel, just the actual upper) replaced, and noticed this last night. I am going to reach out to Remsport today & see what they say-I didnt think it shouldve passed either, but, not sure if its something they would even check, as I sent them the parts. They are great guys, and I am sure can help me out with this. I just was wondering if anyone else knew about this issue-hopefully, they will learn from it if they dont-check your feed ramps if you are having feed problems!!

 

[Supermoto]

you can have the receiver cut for the ramps. Its something that should have been realized prior to the build

 

[op4guy]

I am oldsoldier's brother and basically we were out shooting and started to end up with the feeding/jam issues. Originally I thought it had something to do with the bolt stop catching early due to a broken spring but after we got it home I noticed the ramp difference between the bbl extension and the receiver. We did some research and confirmed this was most likely the culprit.

Yeah he should have caught it but lets face it, he's not an armorer. The installer should have picked up on it during inspection that they were not the same. So it comes down to replace one or the other or have the ramps on the extension ground down and what we're trying to figure out is does anyone know of anyone in the NE area that will actually do this work?

 

[Supermoto]

I am oldsoldier's brother and basically we were out shooting and started to end up with the feeding/jam issues. Originally I thought it had something to do with the bolt stop catching early due to a broken spring but after we got it home I noticed the ramp difference between the bbl extension and the receiver. We did some research and confirmed this was most likely the culprit.

Yeah he should have caught it but lets face it, he's not an armorer. The installer should have picked up on it during inspection that they were not the same. So it comes down to replace one or the other or have the ramps on the extension ground down and what we're trying to figure out is does anyone know of anyone in the NE area that will actually do this work?

whomever did the build take it back to them or Larrocca or back to remsport

 

[Admin]

I am sure Remsport will make it right.

 

[mark2]

Interesting. I just bought a barrel and upper from Remsport and had exactly the same issue. I took a close look and the feed ramps are pretty sloppily ground. I have not contacted them but am considering it. Looks like a new barrel extension will be required, I just don't have the time to head back out there... Great shop but they did it in a rush and the quality suffered, my fault too.

 

[WaldoOneFive]

Good morning all, I have a technical question. I wnet shooting this weekend, and ran into some issues. I was getting misfeeds, and, initially, though it may be the magazines. After trying several different ones, I was STILL getting the same issues. When I got home, my brother & I started looking into it-it couldnt be the mags, as we replicated it with several different ones-ones I KNOW are reliable. So, we found out that it is a feed ramp issue. I have an M4 receiver with a rifle barrel extension. what is happening is that the rounds are catching on the lip (see attached pic), causing the misfeeds (bullet gets pushed into the cartridge itself). I thought I had seen similar issues here with other people, but couldnt find it.
Essentially, is there someone who can grind down & polish the feedramps? Or do I need to order new parts?

Where are you located? I can make the reciever match to the M4 feedramps on the barrel.

 

[oldsoldier29]

I am located in central MA, near Devens. I did send an email out to them, and should hear from them in the next day or so. Its about the same drive for me either way=to them, or to you. If, for some reason, they will not/can not fix, I will let you know. Thanks for the offer, I will let you know.

 

[Remsport Mfg]

Issues

I have already talked to oldsoldier29 about this by email and we will check the feed ramps and do what ever is necessary. I did not konw about the other issue. We will do whatever is necessary to fix this problem.
I will go as far as replacing the barrel for free if necessary.
Please call to let me know when you will be comming down.
Thanks I did not know about this thread.

John

 

[Remsport Mfg]

Mark2 if you are having a problem with your barrel please contact me. Send me your upper or stop in I will replace your barrel if needed.
Thanks
John
413 579 1994

 

[mark2]

John-
Thanks. I appreciate that. I have to wonder if grinding the feed ramp by hand makes a lot of sense (is that how it's done?), seemed kind of messy to me but I'm willing to give it another go. Couldn't you just replace the barrel extension if necessary?
oldsoldier29, I'm not far from you (15 minutes), if you head out maybe we can work something out? Let me know? I'll send you a PM.
Mark

 

[CHAM12]

You could polish and fit the ramp but copy all others saying take it back and have them do it.

 

[CHAM12]

REM SPORT ROCKS

 

[Remsport Mfg]

Too much of a PITA to just replace the extention. If needed I will replace the barrel.
Thanks
John

 

[op4guy]

That is some great CS by Remsport for sure!

 

[oldsoldier29]

Update-met up with John yesterday, problem resolved. John i a GREAT guy-even got to check out some of the projects he is working on. Mark, sorry, checked this a day too late. The grinding & polishing of the feedramp resolved the issue-it took John literally 5 minutes to do. He ran a bunch of rounds through it, with zero issues. I can get some after pics up, so you can see-the lip was removed, it is polished, and is good to go now.

FYI-the mismatch was MY mistake-I had sent him an upper I purchased a few months back, along with my then-current upper, to have them swapped out. It went through a local shop, who sent it to Remsport. The swap was done, he put a few rounds through it, and it worked. This issue wasnt the result of craftsmanship-it was my lack of knowledge of how important that particular piece is. That being said, he STILL stepped up & took care of it for me-and I am grateful or that. John, thank you-was great meeting you, and seeing some of your current projects!

 

[op4guy]

Glad you got it taken care of. Now take that thing out and run a few thousand rounds through it like there is no tomorrow...or you can fly out here in June for an LMS carbine course I am organizing?!?